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DAB Performance of different makes?
Jim Lesurf wrote:
In article , DAB sounds worse than FM wrote: Jim Lesurf wrote: If it *is* the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming. I really do hope you're not trying to suggest what I think you might be trying to suggest. I'm afraid I don't know what you have in mind, so can't comment. Please expand on the above sentence. Not sure what expansion could add as I think I pretty much said what I meant. I thought it would be obvious, but I'll re-phrase it... start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements Judgements about what? About audio quality or reception quality? If the former, get a grip. based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. OTOH if they all use identical, or functionally identically equivalent, circuits in every respect, there may be no such variations, so no such variables would affect what people get. In the absence of detailed information on this point, we can'r really say one way or the other. Can't say what one way or the other? end of re-phrasing So far as I can tell, the above simply puts what I wrote before into rather more words. I hope it is now clear. Indeed, it seems to me to be no more than a fairly standard view of how engineered systems actually work in practice. The way I took what you'd written was that you were trying to suggest that we're hearing bad audio quality because we have poor reception or poor receivers. Am I right? Yeah, Jim, we've all got ****e reception with ****e receivers, and the audio quality is fantastic on everybody else's receivers because they're wonderful and they've got wonderful reception. There you go. That's what you wanted to hear, no? My experience with real engineered systems is that the performances vary to some extent, and with RF RXs the way they may be affected by reception conditions also varies. What, you mean reception quality varies from location to location? Bloody hell. That's a shocker. Not aware of any "suggestions" beyond what I wrote. But if you think there are, please start a new thread on that topic and explain what you had in mind. I can then either confirm what you thought I was "suggesting" or explain that I did not have it in mind. Oh, so now you want some suggestions? Really? I see. Good luck. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Jim Lesurf wrote:
*If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. Here's a good place to start: http://www.digitalradiotech.co.uk/im...io_quality.gif The curve for MP2 is labelled 'LII'. 128kbps is classified as "Annoying". 98% of stereo stationson DAB in the UK use 128kbps. Hope that helps. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Jim Lesurf wrote:
Is there info anywhere on which sets/makers use which chipsets? Or do they regard this as a dark and shameful secret? ;- I suppose manufacturers don't often mention it in specs because it's pretty low-level and most consumers don't care. If you go to the suppliers of the chipsets/modules, though, you may find lists. For example, this lot are a good bunch - worked for them myself for a while, so I'm biased: http://www.frontier-silicon.com/company/success.htm FWIW I've also been interested in seeing if chipsets are available for 'amateur' use as it would be interesting to experiment with them. Anyone know of a source, etc? Nope. When Frontier were smaller - they've expanded almost beyond recognition in just the last year alone - you might've been able to give them a call and ask if you could get a sample of a module. These days they might be, er, a bit too busy to worry about such requests! I suspect it would be pretty expensive as a one-off too. Never hurts to ask mind you. Do they also tend to use the same RF frontend? AFAIK most customers tend to take complete modules including the front end, though the connection from aerial to that front end can be a big source of problems - you'd be amazed how nasty it can be, considering you're basically just after a bit of in-spec wire to get from A to B. Thus an individual user may decide that a more expensive or different RX was justified in their case. Perhaps, though I wouldn't agree personally. At 128kbps, MPEG 1 layer 2 audio really does sound pretty rough, and that's top-end for most stations in the UK. At about 160kbps or over it sounds from OK to pretty good to me; the over-use of dynamic compression is usually much more of a problem than the bitrate. But for the most part, you can hear artefacts on cheap sets, never mind expensive ones; all they'll do is reduce background noise or overall analogue path distortion, which just makes the digital problems easier to hear...! :-) I suppose that, just as with digital TV, some people find digital artefacts from radio much harder to listen to than analogue glitches, whereas other people decide it's the other way around. -- TTFN, Andrew Hodgkinson Find some electronic music at: All sorts of other bits and pieces at: http://www.ampcast.com/pond http://pond.org.uk/ |
DAB Performance of different makes?
Jim Lesurf wrote:
start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. Here's a brief explanation on the type of joint stereo coding MP2 uses (intensity stereo): http://www.audiocoding.com/modules/w...tensity+stereo And in this document BBC R&D say what they think is the "typical" bit rate required for MP2: http://www.bbc.co.uk/rd/pubs/brochur...udiocoding.pdf And it aint 128kbps. And every TV channel on Freeview uses a bit rate of 256kbps or 192kbps. And the German public service broadcaster, ARD, recently added 54 stereo stations to satellite using 320kbps MP2. Why did they do this? Surely if 128kbps is soooo fantastic then 320kbps is simply an incredible waste of bandwidth. Basically, you're looking at completely the wrong place; it's the fking awful codec that's the problem. Sure, poor reception won't help, but so long as you get reception quality in the high-90s then that shows that the BER is okay -- which is the important issue with regards reception quality, obviously. And I may not always agree with Agamemnon, but on this issue he's got it about right: comparing fking slight differences in S/PDIF bitstreams is ridiculous when you've got ****e audio being broadcast. MP2 decoders have to pass stringent accuracy tests, so one decoder that's passed the test will produce virtually identical bitstreams to another that's also passed the test, and I'd expec that they'll all have passed the test. So, overall, so long as you've got a low BER (i.e. high reception quality) and you're using S/PDIF to a reasonable quality DAC then you can really forget the rest. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Andrew Hodgkinson wrote:
Jim Lesurf wrote: Thus an individual user may decide that a more expensive or different RX was justified in their case. Perhaps, though I wouldn't agree personally. At 128kbps, MPEG 1 layer 2 audio really does sound pretty rough, and that's top-end for most stations in the UK. At about 160kbps or over it sounds from OK to pretty good to me; I agree that it *can* sound from okay to pretty good at 160k+, but audio quality is highly variable depending on how difficult the audio is to encode, and 160k and 192k still struggle a lot of the time. the over-use of dynamic compression is usually much more of a problem than the bitrate. I disagree. I think audio processing has a small effect, but a difference in stereo bit rates is a jump of 32kbps, and moving up one bit rate level would be, IMO, a lot better than reducing the audio processing level. I suppose that, just as with digital TV, some people find digital artefacts from radio much harder to listen to than analogue glitches, whereas other people decide it's the other way around. Bloody hell, do they even have brainwash the staff in Frontier-Silicon? ;-) -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
In article ,
DAB sounds worse than FM wrote: It obviously satisfies the listeners it's aimed at otherwise they simply wouldn't use those stations - it's hardly like there's no choice. Thanks for your expert insight. To be perfectly honest, arguing with you or Jeremy is like hitting my head against a brick wall, so I think I'll pass today, thanks. Thank gawd for that. Everyone who cares about ultimate audio quality already knows that DAB isn't for them. And use one of the several alternatives. In the same way as they wouldn't *choose* to use AM. Although might be happy with DAB on a portable radio etc. So why don't you get a life and find something worthwhile to worry about? -- *You never really learn to swear until you learn to drive * Dave Plowman London SW To e-mail, change noise into sound. |
DAB Performance of different makes?
In article ,
DAB sounds worse than FM wrote: You missed out advertising costs. The higher the advertising costs the higher the retail price. The advertising costs for DAB are borne by the BBC... They pay for the adverts of brands of radios? You knew what I meant; don't get clever, it doesn't suit you. It's also very you to not read what has been said but simply trot out your standard responses. Some graduate. Obviously the questions set in your finals were exactly what you expected. -- *If a pig loses its voice, is it disgruntled? Dave Plowman London SW To e-mail, change noise into sound. |
DAB Performance of different makes?
In article ,
DAB sounds worse than FM wrote: It obviously satisfies the listeners it's aimed at otherwise they simply wouldn't use those stations - it's hardly like there's no choice. Actually, there is no choice for what I want. When I first bought DAB I bought it because it was advertised as providing CD-quality sound, and I definitely expected it to be better than FM. I now listen via FM. This isn't good enough. Sorry. So you're having another bite at the cherry? Now you *claim* to be an expert in all things digital. Degrees in this and that. But expected a data reduced transmission system to be as good as CD? And I would have thought one with your claimed intelligence would know not to take every advert at face value. -- *Why do the two "sanction"s (noun and verb) mean opposites?* Dave Plowman London SW To e-mail, change noise into sound. |
DAB Performance of different makes?
DAB sounds worse than FM wrote:
Mark Carver wrote: wrote: Okay, I'll rephrase it: If you were on a desert island and you were allowed to watch one TV channel and the choice was out of any of the shopping channels on Freeview or Channel 4, which would you choose? I'm totally Lost on that question. Is Lost good? I watched the first episode and I thought it looked too corny, so I didn't continue, but other people do seem to have been pretty positive about it. TBH I've not seen it myself. Anyway, I'll stop mucking around, given a choice between Freeview shopping channels and C4 I'd of course go for the latter. digital spy poster mode If you could only have one channel, what would it be ? /digital spy poster mode -- Mark Please replace invalid and invalid with gmx and net to reply. |
DAB Performance of different makes?
Dave Plowman (News) wrote:
In article , DAB sounds worse than FM wrote: It obviously satisfies the listeners it's aimed at otherwise they simply wouldn't use those stations - it's hardly like there's no choice. Thanks for your expert insight. To be perfectly honest, arguing with you or Jeremy is like hitting my head against a brick wall, so I think I'll pass today, thanks. Thank gawd for that. Everyone who cares about ultimate audio quality already knows that DAB isn't for them. And use one of the several alternatives. In the same way as they wouldn't *choose* to use AM. Although might be happy with DAB on a portable radio etc. So why don't you get a life and find something worthwhile to worry about? STFU & FO YK. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
DAB sounds worse than FM wrote:
Jim Lesurf wrote: In article , DAB sounds worse than FM wrote: Jim Lesurf wrote: If it *is* the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming. I really do hope you're not trying to suggest what I think you might be trying to suggest. I'm afraid I don't know what you have in mind, so can't comment. Please expand on the above sentence. Not sure what expansion could add as I think I pretty much said what I meant. I thought it would be obvious, but I'll re-phrase it... start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements Judgements about what? About audio quality or reception quality? If the former, get a grip. See, it just goes to show, The Three Degrees and reading all those papers was a waste of time. You can't read. If you can read the individual words, you don't seem to able to recognise them as a coherent whole as a meaningful sentence. And if you do recognise them as a meaningful sentence, you're obviously tooooo thick, The Three Degrees or no, to comprehend what they're saying. I didn't have any problem understanding what Jim meant, either the first or the remedial version, and I'd suspect anyone else still reading this thread didn't have much trouble either. That's the problem - you don't have any comprehension of all the issues, which makes your opinion largely irrelevant. There is much more to delivering DAB from the bradcaster to the end user than kust the choice of bitrate. Until you can understand that, and put your gripes about bitrate into some sort of meaningful context, you're on a hiding to nothing. Like many single-issue objectors you don't base your wants or abjectives on any sort of meaningful framework, and you're wasting your and everyone else's time. Oh, and pointing to crap you've written yourself as some sort of justification for a point of view is, ummm, just stupid. Which magazine was it you've supposedly been writing for, again? -- Nobby |
DAB Performance of different makes?
Dave Plowman (News) wrote:
In article , DAB sounds worse than FM wrote: It obviously satisfies the listeners it's aimed at otherwise they simply wouldn't use those stations - it's hardly like there's no choice. Actually, there is no choice for what I want. When I first bought DAB I bought it because it was advertised as providing CD-quality sound, and I definitely expected it to be better than FM. I now listen via FM. This isn't good enough. Sorry. So you're having another bite at the cherry? Now you *claim* to be an expert in all things digital. Not *all* things digital. Degrees in this and that. But expected a data reduced transmission system to be as good as CD? Oh dear. Sorry, I thought you were aware of the term "transparent"? I thought you were an expert on audio? Sigh. Basically, if you use high enough bit rates the act of encoding becomes effectively transparent (i.e. it doesn't add any perceptible artefacts). *That* is what I was referring to, because it is to all intents and purposes CD-quality. Here's a test for you: Rip a track from a CD. Encode it to 320kbps MP3 using a decent MP3 encoder. Decode the MP3 back to WAV. Load the original WAV and the WAV that's been encoded to and decoded from MP3 into http://ff123.net/abchr/abchr.html. Then see if you can tell the difference. If you can then you'll likely have excellent hearing. And I would have thought one with your claimed intelligence would know not to take every advert at face value. Do be quiet. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Dave Plowman (News) wrote:
In article , DAB sounds worse than FM wrote: You missed out advertising costs. The higher the advertising costs the higher the retail price. The advertising costs for DAB are borne by the BBC... They pay for the adverts of brands of radios? You knew what I meant; don't get clever, it doesn't suit you. It's also very you to not read what has been said but simply trot out your standard responses. Some graduate. Obviously the questions set in your finals were exactly what you expected. Believe me, Dave, you wouldn't have stood a chance in some of the exams I've taken. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Mark Carver wrote:
DAB sounds worse than FM wrote: Mark Carver wrote: wrote: Okay, I'll rephrase it: If you were on a desert island and you were allowed to watch one TV channel and the choice was out of any of the shopping channels on Freeview or Channel 4, which would you choose? I'm totally Lost on that question. Is Lost good? I watched the first episode and I thought it looked too corny, so I didn't continue, but other people do seem to have been pretty positive about it. TBH I've not seen it myself. Anyway, I'll stop mucking around, given a choice between Freeview shopping channels and C4 I'd of course go for the latter. digital spy poster mode If you could only have one channel, what would it be ? /digital spy poster mode C4. Although I'd miss sport. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
"Mark Carver" wrote in message ... snip digital spy poster mode If you could only have one channel, what would it be ? /digital spy poster mode Probably BBC2 Circa 1980 '85, including the Saturday (and Sunday?) morning OU programmes. |
DAB Performance of different makes?
Nobody Here wrote:
DAB sounds worse than FM wrote: Jim Lesurf wrote: In article , DAB sounds worse than FM wrote: Jim Lesurf wrote: If it *is* the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming. I really do hope you're not trying to suggest what I think you might be trying to suggest. I'm afraid I don't know what you have in mind, so can't comment. Please expand on the above sentence. Not sure what expansion could add as I think I pretty much said what I meant. I thought it would be obvious, but I'll re-phrase it... start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements Judgements about what? About audio quality or reception quality? If the former, get a grip. See, it just goes to show, The Three Degrees and reading all those papers was a waste of time. Hahahhahahahahahahahahahahaha. You can't read. If you can read the individual words, you don't seem to able to recognise them as a coherent whole as a meaningful sentence. Be quiet you moron. And if you do recognise them as a meaningful sentence, you're obviously tooooo thick, The Three Degrees or no, to comprehend what they're saying. Yawn. I didn't have any problem understanding what Jim meant, I wanted to make sure before I slagged off his hypothesis. either the first or the remedial version, and I'd suspect anyone else still reading this thread didn't have much trouble either. That's the problem - you don't have any comprehension of all the issues, Do be quiet analogue man. Come back when you've got a clue about digital technology. Okay? which makes your opinion largely irrelevant. In your dreams fat boy. There is much more to delivering DAB from the bradcaster to the end user than kust the choice of bitrate. My God, I can see how you got all those imaginary journal papers published. You really are an incredibly intelligent person to figure that one out. Until you can understand that, and put your gripes about bitrate into some sort of meaningful context, you're on a hiding to nothing. You see, that shows how little you do understand this issue. Like many single-issue objectors you don't base your wants or abjectives on any sort of meaningful framework, and you're wasting your and everyone else's time. Try and lecture someone else that actually gives a **** about what you think. Let's face it, all your views on me are now tainted to the extent that they're meaningless drivel being written out of spite. Nothing more, nothing less. The vast majority of what you're coming out with are generic criticisms that could be thrown at anybody in any field, and the rest is just systems ******** along the lines of "oh, if you knew all the things about all the subsystems" blah de blah. It's irrelevant, I'm afraid. With a digital radio system, if you have a BER (bit error rate) of zero, or near zero, then you're receiving exactly, or virtually exactly, the bitstream that was output from the MPEG encoder. All your RF **** is irrelevant when there's no bit errors. Sorry. Oh, and pointing to crap you've written yourself as some sort of justification for a point of view is, ummm, just stupid. Be quiet. Which magazine was it you've supposedly been writing for, again? I'll tell you after you've answered one of my previous questions to you: what's your name? -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
DAB sounds worse than FM wrote:
Nobody Here wrote: DAB sounds worse than FM wrote: Jim Lesurf wrote: In article , DAB sounds worse than FM wrote: Jim Lesurf wrote: If it *is* the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming. I really do hope you're not trying to suggest what I think you might be trying to suggest. I'm afraid I don't know what you have in mind, so can't comment. Please expand on the above sentence. Not sure what expansion could add as I think I pretty much said what I meant. I thought it would be obvious, but I'll re-phrase it... start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements Judgements about what? About audio quality or reception quality? If the former, get a grip. See, it just goes to show, The Three Degrees and reading all those papers was a waste of time. Hahahhahahahahahahahahahahaha. You can't read. If you can read the individual words, you don't seem to able to recognise them as a coherent whole as a meaningful sentence. Be quiet you moron. And if you do recognise them as a meaningful sentence, you're obviously tooooo thick, The Three Degrees or no, to comprehend what they're saying. Yawn. I didn't have any problem understanding what Jim meant, I wanted to make sure before I slagged off his hypothesis. either the first or the remedial version, and I'd suspect anyone else still reading this thread didn't have much trouble either. That's the problem - you don't have any comprehension of all the issues, Do be quiet analogue man. Come back when you've got a clue about digital technology. Okay? which makes your opinion largely irrelevant. In your dreams fat boy. There is much more to delivering DAB from the bradcaster to the end user than kust the choice of bitrate. My God, I can see how you got all those imaginary journal papers published. You really are an incredibly intelligent person to figure that one out. Until you can understand that, and put your gripes about bitrate into some sort of meaningful context, you're on a hiding to nothing. You see, that shows how little you do understand this issue. Like many single-issue objectors you don't base your wants or abjectives on any sort of meaningful framework, and you're wasting your and everyone else's time. Try and lecture someone else that actually gives a **** about what you think. Let's face it, all your views on me are now tainted to the extent that they're meaningless drivel being written out of spite. Nothing more, nothing less. The vast majority of what you're coming out with are generic criticisms that could be thrown at anybody in any field, and the rest is just systems ******** along the lines of "oh, if you knew all the things about all the subsystems" blah de blah. It's irrelevant, I'm afraid. With a digital radio system, if you have a BER (bit error rate) of zero, or near zero, then you're receiving exactly, or virtually exactly, the bitstream that was output from the MPEG encoder. All your RF **** is irrelevant when there's no bit errors. Sorry. Oh, and pointing to crap you've written yourself as some sort of justification for a point of view is, ummm, just stupid. Be quiet. Which magazine was it you've supposedly been writing for, again? I'll tell you after you've answered one of my previous questions to you: what's your name? You see, all you can do is either tell people who think you're full of crap to shut up, slag them off as in "fat boy", or call them a moron without bothering to justify why you think I'm a moron. You've absolutely no answers for the criticisims I've made of you other than that. Somehow you seem to on the one hand expect the rest of us to believe you because you've apparently got The Three Degrees, because you've said so, but you're not prepared to believe I've had lots of journal publications, even though I've said so. How do you reconcile that, then? I've no need to tell you my name. I'm not trying to prove anything based on my qualifications, I'm quite happy that my posts are internally complete and I don't need to lean on anything external in "proof". You, on the other hand, are using your qualifications in part as a "proof" of your superiority to many others here. If you want to do that, you'll have to supply some external refernce, or you just make yourself look (really) stupid. One of those "proofs" might be a pointer to the HiFi magazine you've alledgedly written for. Otherwise, people might think you were lying, and that would undermine you just a bit, wouldn't it? -- Nobby |
DAB Performance of different makes?
Nobody Here wrote:
You see, all you can do is either tell people who think you're full of crap to shut up, slag them off as in "fat boy", or call them a moron without bothering to justify why you think I'm a moron. You've absolutely no answers for the criticisims Au contraire. I wrote this which does answer your criticism: "With a digital radio system, if you have a BER (bit error rate) of zero, or near zero, then you're receiving exactly, or virtually exactly, the bitstream that was output from the MPEG encoder. All your RF **** is irrelevant when there's no bit errors. Sorry." I've made of you other than that. Somehow you seem to on the one hand expect the rest of us to believe you because you've apparently got The Three Degrees, because you've said so, but you're not prepared to believe I've had lots of journal publications, even though I've said so. How do you reconcile that, then? I know I'm honest, whereas I don't know whether you're honest. I've no need to tell you my name. Sure, you don't have to. But I don't see why you want to know which hi-fi magazine I write for if you won't tell me your name. How do you reconcile that, then? I'm not trying to prove anything based on my qualifications, I'm quite happy that my posts are internally complete Hardly. You know jack**** about the digital technologies, or you would have at least tested out to see if I really do know what I'm talking about. But you can't, because that's not your field, so you had to resort to generic criticisms, although you don't actually understand the system, so you even screwed up those criticisms. and I don't need to lean on anything external in "proof". You, on the other hand, are using your qualifications in part as a "proof" of your superiority to many others here. As I've said a few times now, I only use them when I'm actually being called thick. Sorry if you don't like that practice. If you want to do that, you'll have to supply some external refernce, or you just make yourself look (really) stupid. As I said last time, your views on me are just bitter bile, and as such it's water off a duck's back. One of those "proofs" might be a pointer to the HiFi magazine you've alledgedly written for. I don't need to prove jack****. I know I write for a hi-fi magazine (hi-fi shouldn't be capitalised - why did you do that?), and that's all that matters. Otherwise, people might think you were lying, I know that some people on this newsgroup could vouch for me. and that would undermine you just a bit, wouldn't it? If I was lying then it would obviously undermine whatever I say. But I'm not lying. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
DAB sounds worse than FM wrote:
Bloody hell, do they even have brainwash the staff in Frontier-Silicon? ;-) Heh :-) I wish, then I'd actually be able to get a DAB radio and not spend the whole time being annoyed by the sound quality. But in truth - for me, dynamic compression is the thing I notice. Like, it seems, an awful lot of other software engineers, I dabble in synths for fun now and again. So I'm very much an amateur but know a small amount more than average about what goes on when mixing tracks; I'm a bit more critical about audio as a result. Consequently I really do find many commercial channels practically unlistenable on any transport mechanism. The likes of 1Xtra just sound out and out distorted - as in, really heavily very distorted - on DAB or Freeview. The likes of Q103 in Cambridge on FM is a simlar story. All I can hear is volume pumping, and a total absence of whatever energy might have once been mixed into the track resulting from it being compressed to a uniform LOUD. Quite a few CDs these days are going the same way. For example, Beautiful South's carefully mastered acoustic output used to be wonderful, but the subtleties have been compressed away in later albums, ever since round about Blue Is The Colour. I've never been able to listen to Texas albums for very long for a similar reason. It just bugs me. One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. -- TTFN, Andrew Hodgkinson Find some electronic music at: All sorts of other bits and pieces at: http://www.ampcast.com/pond http://pond.org.uk/ |
DAB Performance of different makes?
Andrew Hodgkinson wrote:
DAB sounds worse than FM wrote: Bloody hell, do they even have brainwash the staff in Frontier-Silicon? ;-) Heh :-) I wish, then I'd actually be able to get a DAB radio and not spend the whole time being annoyed by the sound quality. That's not a very good advert if their ex-engineers say that. :-) But in truth - for me, dynamic compression is the thing I notice. Yeah, I certainly dislike stations that use high levels of processing. I suppose it has its uses for listening on a small portable radio, portable stereo or in the car, but on a hi-fi system it's just far too in yer face. Like, it seems, an awful lot of other software engineers, I dabble in synths for fun now and again. So I'm very much an amateur but know a small amount more than average about what goes on when mixing tracks; I'm a bit more critical about audio as a result. Consequently I really do find many commercial channels practically unlistenable on any transport mechanism. The likes of 1Xtra just sound out and out distorted - as in, really heavily very distorted - on DAB or Freeview. Heart and Galaxy always seem to be ultra-loud as well. The likes of Q103 in Cambridge on FM is a simlar story. All I can hear is volume pumping, and a total absence of whatever energy might have once been mixed into the track resulting from it being compressed to a uniform LOUD. Absolutely. I've always listened to Radio 1 quite a bit, and I think it used to be quite a bit louder than it is now, and it's a lot better as a result. Quite a few CDs these days are going the same way. For example, Beautiful South's carefully mastered acoustic output used to be wonderful, but the subtleties have been compressed away in later albums, ever since round about Blue Is The Colour. I've never been able to listen to Texas albums for very long for a similar reason. It just bugs me. I don't know how widespread this is, but someone said that albums released on DVD-Audio aren't compressed to buggery whereas the CD versions are. As I say, I'm not sure whether he was referring to DVD-Audio releases in general or just a few he'd bought. You can imagine they'd do this though, because it would be more the audiophile market buying DVD-Audio at the moment, so they would far prefer it if there's a wide dynamic range. One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. I once quoted a sentence from the DAB spec to Lindsay Cornell where it said something along the lines of "the full dynamic range must be preserved", and his answer was simply "we don't have to stick to the DAB specification." ;-) Since then Robert Orban (Mr Optimod himself) told me the DRC on DAB isn't really good enough for wideband music. Obviously he's got a major vested interest in this being true, so I don't know how much truth there is in it, but at the end of the day no pop or rock stations on DAB use DRC, which suggests that he was right, or he's got very persuasive salesmen. Personally, I think they should've specified DRC but make it flexible so that companies like Omnia and Optimod can generate their own streams that they've optimised. The thing is though it would consume bit rate, and we all know that the broadcasters don't like to waste bit rate unless absolutely necessary. ;-) -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Bored of this, so I'll be brief.
Nobody Here wrote: DAB sounds worse than FM wrote: Nobody Here wrote: You see, all you can do is either tell people who think you're full of crap to shut up, slag them off as in "fat boy", or call them a moron without bothering to justify why you think I'm a moron. You've absolutely no answers for the criticisims Au contraire. I wrote this which does answer your criticism: "With a digital radio system, if you have a BER (bit error rate) of zero, or near zero, then you're receiving exactly, or virtually exactly, the bitstream that was output from the MPEG encoder. All your RF **** is irrelevant when there's no bit errors. Sorry." Eh? When did I day anything about bit errors, RF **** or anything else? I've never mentioned any of that even once in any post. Ever. You're getting yourself confused, lad. I've never, ever, made a single comment about any of that stuff to you (or anyone else here, for that matter). Oops, says a bit about your credibility and comprehension skills, eh? I've made of you other than that. Somehow you seem to on the one hand expect the rest of us to believe you because you've apparently got The Three Degrees, because you've said so, but you're not prepared to believe I've had lots of journal publications, even though I've said so. How do you reconcile that, then? I know I'm honest, whereas I don't know whether you're honest. Exactly. You've said he words, now see if you can get the point. I've no need to tell you my name. Sure, you don't have to. But I don't see why you want to know which hi-fi magazine I write for if you won't tell me your name. How do you reconcile that, then? Because, quite simply, (and I mean really really simply) you are telling us that *you* have some special abilities *because* you have The Three Degrees, read The Thousands of Papers, and Write for The HiFi Magazine. On the other hand, I'm not claiming that my education and qualifications gives me *any* special abilities - I'm claiming nothing based on *my* education. I mentioned them simply as a counterpoint to your assertion that somehow your alleged education gives you some sort of superiority over other contributors here. You apparently don't see any potential flaws in your expectation that others should accept your putative qualifications at face value while at the same time disbelieving mine. That'd be because you're thick. I'm not trying to prove anything based on my qualifications, I'm quite happy that my posts are internally complete Hardly. You know jack**** about the digital technologies, or you would have at least tested out to see if I really do know what I'm talking about. But you can't, because that's not your field, so you had to resort to generic criticisms, although you don't actually understand the system, so you even screwed up those criticisms. Oh, so I have a "field" do I? And you know what that is how? You asked for some advice about reversing video or something, and from a cursory read of what you wrote it looked like you do analogue electronics. I might be wrong, but I very, very much doubt you know much about digital. Have I given you one inkling of my "field"? Or are you jumping to conclusions based on your own sad little preconceptions? Do I need to test you to see if you know what you're talking about? You ever so comprehensive website My website is aimed at the average man in the street, not engineers. It's not supposed to be comprehensive. that you point people to as the proof of all your blather gives plenty enough information for me to see how much you really understand of the stuff you're blathering on about. Where exactly have I mentioned my website as being proof of my understanding of the subject? As I've already pointed out I've never engaged you in one iota of debate about the technicalities of DAB. Neither am I interested in doing so, not at least until you gain a little maturity, experience, and understanding. That'll be a long time. and I don't need to lean on anything external in "proof". You, on the other hand, are using your qualifications in part as a "proof" of your superiority to many others here. As I've said a few times now, I only use them when I'm actually being called thick. Sorry if you don't like that practice. If you want to do that, you'll have to supply some external refernce, or you just make yourself look (really) stupid. As I said last time, your views on me are just bitter bile, and as such it's water off a duck's back. And so why do you keep responding? Why do you? You said you would ignore me... Also, I could be wrong, but I don't remember you writing "bitter bile" or "water off a duck's back" in any previous post directed at me. Fertile imagination? Or perhaps you're confusing we with someone else. What? One of those "proofs" might be a pointer to the HiFi magazine you've alledgedly written for. I don't need to prove jack****. I know I write for a hi-fi magazine (hi-fi shouldn't be capitalised - why did you do that?), and that's all that matters. Apparently not, or you wouldn't try to use it as proof you're not thick. I didn't use that as proof that I'm not thick, I used it because old Jeremy said everybody was laughing at what I wrote, so I asked him why I've been asked to write for a hi-fi mag. Otherwise, people might think you were lying, I know that some people on this newsgroup could vouch for me. Oh, yeah, they've been shouting loud and long from the rooftops. Ask Bill Wright then (he of Rigger's Diary threads. As for not shouting loud etc, they're probably as bored with this thread as I am, and haven't bothered to read your crap. I bet you know hundreds of people who think you're a real card, and loads of girls want to sleep with you, too! and that would undermine you just a bit, wouldn't it? If I was lying then it would obviously undermine whatever I say. But I'm not lying. Of course not. That's why, seeing as you're so proud of your contributions to a HiFi magazine, you're so unwilling to show us where they are. They're usually found in newsagents. Where else would they be? Why would that be? Anyone with an axe the size of yours to grind would be pointing all and sundry towards a published version of their opinion. But you won't tell anyone which magazine was *so impressed* with your website that they asked you to write articles for them. Is it published on some other planet, like Uranus? I see. So you don't want to give your name, but you want me to say which hi-fi mag I write for? No, I don't want to, sorry. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
On Tue, 25 Oct 2005 23:42:49 GMT, DAB sounds worse than FM wrote:
Nobody Here wrote: Oh, so I have a "field" do I? And you know what that is how? You asked for some advice about reversing video or something, and from a cursory read of what you wrote it looked like you do analogue electronics. I might be wrong, but I very, very much doubt you know much about digital. Oh dear, that's clearly the same cursory read you've applied to the Thousands of Papers. Do you often draw such wide-reaching inferences from so little information? Oh, yeah, perhaps you do. My website is aimed at the average man in the street, not engineers. It's not supposed to be comprehensive. And yet you use it as illustration of your views to people here, many of whome are clearly engineers, and in submissions to Ofcom. I wonder if you made the people at Ofcom aware that you were the author of the site you used for 3 of the 5 references in your, umm, submission? Why would that be? Anyone with an axe the size of yours to grind would be pointing all and sundry towards a published version of their opinion. But you won't tell anyone which magazine was *so impressed* with your website that they asked you to write articles for them. Is it published on some other planet, like Uranus? I see. So you don't want to give your name, but you want me to say which hi-fi mag I write for? No, I don't want to, sorry. That's because there *is* no magazine, is there. It's just a figment of your imagination, isn't it. Either that or a down-right lie used in a sad attept to boost your own credibility. Neither of which shows you in a very positive light, do they? I wonder now if The Three Degrees are real? Do I care? Nope. You're clearly a twerp, sounds like your unemployable (probably overqualified for most jobs, eh?), and gotta lotta growing up to do. I am truly sorry I dragged myself back into this, coz how you live your sad little life is no concern of mine, so I really do promise I'll leave it there. I'll leave the last word to you, so that you can bolster your self-esteem again. Tata. -- Nobby |
DAB Performance of different makes?
Nobody Here wrote:
On Tue, 25 Oct 2005 23:42:49 GMT, DAB sounds worse than FM wrote: Nobody Here wrote: Oh, so I have a "field" do I? And you know what that is how? You asked for some advice about reversing video or something, and from a cursory read of what you wrote it looked like you do analogue electronics. I might be wrong, but I very, very much doubt you know much about digital. Oh dear, that's clearly the same cursory read you've applied to the Thousands of Papers. Do you often draw such wide-reaching inferences from so little information? Oh, yeah, perhaps you do. Oh, and another thing: you also said that you did a degree in Electronics. I'm not saying I know what you do, but you have given hints towards what you do for a living. I wouldn't expect you to own up to what you actually do even if I hit the nail on the head, because your whole argument-style is to throw generic insults and criticisms while claiming that you're somehow knowledgable about the subject but without actually saying what your field of expertise is -- i.e. leave it open in order to suggest expertise in the field being discussed. As I say, I don't know for a fact what you do, but based on the evidence I think it's a reasonable guess that you're an analogue or RF electronics engineer. In which case, don't lecture me about digital stuff. Okay? My website is aimed at the average man in the street, not engineers. It's not supposed to be comprehensive. And yet you use it as illustration of your views to people here, many of whome whome? Are you thick or sumfing? are clearly engineers, and in submissions to Ofcom. I wonder if you made the people at Ofcom aware that you were the author of the site you used for 3 of the 5 references in your, umm, submission? I can't remember if I did or not, but I know that Mark Thomas (who's in charge of "regulating" broadcasting technical quality) is perfectly aware of who I am and which website I write. Anyway, although I can't remember what the referenes were for, I don't see any problem with referring to my own website. Why would that be? Anyone with an axe the size of yours to grind would be pointing all and sundry towards a published version of their opinion. But you won't tell anyone which magazine was *so impressed* with your website that they asked you to write articles for them. Is it published on some other planet, like Uranus? I see. So you don't want to give your name, but you want me to say which hi-fi mag I write for? No, I don't want to, sorry. That's because there *is* no magazine, is there. Have you asked Bill Wright yet? It's just a figment of your imagination, isn't it. Either that or a down-right lie used in a sad attept to boost your own credibility. Neither of which shows you in a very positive light, do they? Yawn. I wonder now if The Three Degrees are real? They're far more real than your supposed journal papers. Do I care? Nope. Really? If it wasn't bothering you you wouldn't be arguing with me here and now, sunshine. You're clearly a twerp, sounds like your That should be 2 words: "you're". Are you thick of sumfink? unemployable (probably overqualified for most jobs, eh?), and gotta lotta growing up to do. I am truly sorry I dragged myself back into this, coz how you live your sad little life *My* sad little life? is no concern of mine, so I really do promise I'll leave it there. I'll leave the last word to you, so that you can bolster your self-esteem again. Oh, *I'm* the one with self-esteem issues, am I? I think not. BTW, doesn't it strike you as ironic that your rants are all written under the assumption that you're inherently superior to me, which is the precise thing that you slag me off for? Oh well. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
One of the things that excited me most about DAB when the specs were
being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... -- Tony Sayer |
DAB Performance of different makes?
In article ,
tony sayer wrote: One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... It did/does include the ability to do a fairly straightforward dynamic range compression intended for use in cars, etc. However, most of the broadcasters have decided to do this at source these days. Which can often have a worse effect on sound quality than low bit rate DAB... -- *If I throw a stick, will you leave? Dave Plowman London SW To e-mail, change noise into sound. |
DAB Performance of different makes?
Dave Plowman (News) wrote:
In article , tony sayer wrote: One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... It did/does include the ability to do a fairly straightforward dynamic range compression intended for use in cars, etc. However, most of the broadcasters have decided to do this at source these days. Which can often have a worse effect on sound quality than low bit rate DAB... WTF do you know about that? You haven't got the first idea about bit rate reduced MPEG audio coding, so don't try and suggest that you do. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
I see. So you don't want to give your name, but you want me to say which
hi-fi mag I write for? No, I don't want to, sorry. That's because there *is* no magazine, is there. It's just a figment of your imagination, isn't it. Either that or a down-right lie used in a sad attept to boost your own credibility. Neither of which shows you in a very positive light, do they? In fact Steve Green does write for a hi-fi mag. Every month. It's an interesting read as well. If Steve isn't going to tell you which mag then I won't either, but it's one of the upmarket, intelligent ones. You'd better get down to WH Smiths! Bill |
DAB Performance of different makes?
"DAB sounds worse than FM" wrote in message ... Dave Plowman (News) wrote: In article , tony sayer wrote: One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... It did/does include the ability to do a fairly straightforward dynamic range compression intended for use in cars, etc. However, most of the broadcasters have decided to do this at source these days. Which can often have a worse effect on sound quality than low bit rate DAB... WTF do you know about that? You haven't got the first idea about bit rate reduced MPEG audio coding, so don't try and suggest that you do. You really so think you are Gods gift, FFS boy, grow up. |
DAB Performance of different makes?
wrote:
I see. So you don't want to give your name, but you want me to say which hi-fi mag I write for? No, I don't want to, sorry. That's because there *is* no magazine, is there. It's just a figment of your imagination, isn't it. Either that or a down-right lie used in a sad attept to boost your own credibility. Neither of which shows you in a very positive light, do they? In fact Steve Green does write for a hi-fi mag. Every month. It's an interesting read as well. If Steve isn't going to tell you which mag then I won't either, but it's one of the upmarket, intelligent ones. You'd better get down to WH Smiths! Thanks Bill. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
In article , DAB sounds worse
than FM wrote: Jim Lesurf wrote: In article , DAB sounds worse than FM wrote: [snip] start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements Judgements about what? About what I described. For example: If two different RXs have different sensitivities one may make errors in data recovery in circumstances when another does not. This may mean they do not deliver the same results for some users. About audio quality or reception quality? If the former, get a grip. Perhaps you should "get a grip" on what I am actually raising, as opposed to making assumptions and jumping to conclusions which may be irrelevant to what I am trying to find out about.... :-) based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. OTOH if they all use identical, or functionally identically equivalent, circuits in every respect, there may be no such variations, so no such variables would affect what people get. In the absence of detailed information on this point, we can'r really say one way or the other. Can't say what one way or the other? Can't say which RX might function better than another in difficult reception situations of various kinds. Sorry, but I thought this would be clear from what I had written. end of re-phrasing So far as I can tell, the above simply puts what I wrote before into rather more words. I hope it is now clear. Indeed, it seems to me to be no more than a fairly standard view of how engineered systems actually work in practice. The way I took what you'd written was that you were trying to suggest that we're hearing bad audio quality because we have poor reception or poor receivers. Am I right? No. I'm afraid that you had not understood what I wrote, and are jumping to an incorrect conclusion about what I had in mind. I trust this is now clear. However *some* people may not get the same results as others, thus until we have some information on that point we need to proceed with some caution. Yeah, Jim, we've all got ****e reception with ****e receivers, and the audio quality is fantastic on everybody else's receivers because they're wonderful and they've got wonderful reception. There you go. That's what you wanted to hear, no? No. It might help you to discuss things if you took care not to jump to conclusions and then make such statements as the above. My experience with real engineered systems is that the performances vary to some extent, and with RF RXs the way they may be affected by reception conditions also varies. What, you mean reception quality varies from location to location? Bloody hell. That's a shocker. Since it is obvious that reception conditions do vary, it follows that the questions I have been asking can be expected to have some relevance for some users. Thus my interest in answers to those questions. Not aware of any "suggestions" beyond what I wrote. But if you think there are, please start a new thread on that topic and explain what you had in mind. I can then either confirm what you thought I was "suggesting" or explain that I did not have it in mind. Oh, so now you want some suggestions? Really? I see. Good luck. My "luck" seems to have been mixed. :-) "Good" in that you said what you suspected, and I could then point out you have jumped to an erronious conclusion. I did not write what you seem to be assuming. Nor do I think it. "Bad" in that this thread has still be taken up with your concerns about the use of DAB by the BBC (and other broadcasters). Whereas my questions relate to the performance of RXs, not the behaviour of the BBC (and other broadcasters). I have been interested in finding some answers for the points I raised. Ideally, some useful measurements, etc, on DAB RXs. Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
DAB Performance of different makes?
In article , DAB sounds worse than
FM wrote: Jim Lesurf wrote: *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. Here's a good place to start: http://www.digitalradiotech.co.uk/im...io_quality.gif The curve for MP2 is labelled 'LII'. 128kbps is classified as "Annoying". 98% of stereo stationson DAB in the UK use 128kbps. Hope that helps. Afraid not. When you wrote the above you were apparently misunderstanding the questions I have been raising. I am not asking about bit rates or data reduction schemes. Nor about the subjective results of them. Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
DAB Performance of different makes?
In article , Andrew Hodgkinson
wrote: Jim Lesurf wrote: Is there info anywhere on which sets/makers use which chipsets? Or do they regard this as a dark and shameful secret? ;- I suppose manufacturers don't often mention it in specs because it's pretty low-level and most consumers don't care. If you go to the suppliers of the chipsets/modules, though, you may find lists. For example, this lot are a good bunch - worked for them myself for a while, so I'm biased: http://www.frontier-silicon.com/company/success.htm Thanks for the above. :-) FWIW I've also been interested in seeing if chipsets are available for 'amateur' use as it would be interesting to experiment with them. Anyone know of a source, etc? Nope. When Frontier were smaller - they've expanded almost beyond recognition in just the last year alone - you might've been able to give them a call and ask if you could get a sample of a module. These days they might be, er, a bit too busy to worry about such requests! I suspect it would be pretty expensive as a one-off too. Never hurts to ask mind you. OK. I may try my luck sometime. FWIW I am hoping sometime to add DAB/DTTV/CODFM/etc to the subjects I lecture upon and include in the 'Scots Guide'. Might be nice to have some chips for the undergrad teaching labs as well... Maybe I can blag some on that sort of basis... :-) Do they also tend to use the same RF frontend? AFAIK most customers tend to take complete modules including the front end, though the connection from aerial to that front end can be a big source of problems - you'd be amazed how nasty it can be, considering you're basically just after a bit of in-spec wire to get from A to B. I can understand the above, having investigated some FM tuners and radios in the past. :-) Thus an individual user may decide that a more expensive or different RX was justified in their case. Perhaps, though I wouldn't agree personally. At 128kbps, MPEG 1 layer 2 audio really does sound pretty rough, and that's top-end for most stations in the UK. At about 160kbps or over it sounds from OK to pretty good to me; the over-use of dynamic compression is usually much more of a problem than the bitrate. But for the most part, you can hear artefacts on cheap sets, never mind expensive ones; all they'll do is reduce background noise or overall analogue path distortion, which just makes the digital problems easier to hear...! :-) I have no reason to disagree with the above. However my interest in this thread is in areas like those where the user finds the signal levels are low or there is RF interference. Thus where one RX may produce more uncorrected errors than another, etc. Thus making things worse. Also in the possibility that different RXs may deal with reception errors in different ways. Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
DAB Performance of different makes?
In article , Andrew Hodgkinson
wrote: DAB sounds worse than FM wrote: Bloody hell, do they even have brainwash the staff in Frontier-Silicon? ;-) Heh :-) I wish, then I'd actually be able to get a DAB radio and not spend the whole time being annoyed by the sound quality. But in truth - for me, dynamic compression is the thing I notice. I can't as yet really compare with DAB. But I have spent some time comparing FM with DTTV R3, etc. This has seemed to show up when FM is level compressed, and also makes the FM background noise level more noticable. Years of listening to FM seem to have made me become 'acclimatised' to these things.[1] But comparing with DTTV helps show them up. Thus for R3 DTTV/FM the imperfections differ in practice. As you wrote in a previous posting, the decision would then vary with the user's sensitivities and preferences. Slainte, Jim [1] I have also been transferring old R3 recordings (mostly 20-25 years old) onto CD recently, and these old recordings also sometimes show less level compression than recent broadcasts, albiet with the noise being more obvious. So I have the impression that practice in this respect has changed over the years. -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
DAB Performance of different makes?
In article , DAB sounds worse
than FM wrote: [snip] I don't know how widespread this is, but someone said that albums released on DVD-Audio aren't compressed to buggery whereas the CD versions are. Can't comment on DVD-A. However I recently did an analysis of a Hendrix CD re-issue with a fancy label. This showed the sounds spent an alarming fraction of the time within 1dB of clipping. Nothing like the statistics of any real sounds or older CDs I've analysed in the same way. Looked very much like being heavily processed for re-issue to give a sound level stuck at max all the time. This is wandering a bit OT for this group, though... :-) Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
DAB Performance of different makes?
On 2005-10-26, Dave Plowman (News) wrote:
In article , tony sayer wrote: One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... It did/does include the ability to do a fairly straightforward dynamic range compression intended for use in cars, etc. However, most of the broadcasters have decided to do this at source these days. Which can often have a worse effect on sound quality than low bit rate DAB... Apart from the bad effects on music, doing the dynamic range compression at source is reported to have a significant effect on the MPEG layer 2 codec. "This audio codec, used in DAB, performs very poorly when processing dynamically compressed audio. typically 1 grading point below the figures quoted in section 1.2.3. When dynamic range compression is removed, the performance of DAB improves significantly." Dr David J M Robinson, Department of Electronic Systems Engineering, University of Essex. The grading points referred to are the oft quoted "not annoying", "slightly annoying", "annoying" etc. grading points. I think he gets much of his data from Soulodre et al, in the March 1998 volume of JAES. -- John Phillips |
DAB Performance of different makes?
In article ,
DAB sounds worse than FM wrote: Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... It did/does include the ability to do a fairly straightforward dynamic range compression intended for use in cars, etc. However, most of the broadcasters have decided to do this at source these days. Which can often have a worse effect on sound quality than low bit rate DAB... WTF do you know about that? You haven't got the first idea about bit rate reduced MPEG audio coding, so don't try and suggest that you do. Very good, pet. Now go back to the nursery and annoy the other toddlers. -- *Why does the sun lighten our hair, but darken our skin? Dave Plowman London SW To e-mail, change noise into sound. |
DAB Performance of different makes?
Jim Lesurf wrote:
In article , DAB sounds worse than FM wrote: Jim Lesurf wrote: In article , DAB sounds worse than FM wrote: [snip] start of re-phrasing *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements Judgements about what? About what I described. For example: If two different RXs have different sensitivities one may make errors in data recovery in circumstances when another does not. This may mean they do not deliver the same results for some users. About audio quality or reception quality? If the former, get a grip. Perhaps you should "get a grip" on what I am actually raising, as opposed to making assumptions and jumping to conclusions which may be irrelevant to what I am trying to find out about.... :-) Really? This is what you said originally: "If it is the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming." By that I read it that you're trying to cast doubt on the assessments myself and some others that are critical about DAB. There will always be bit errors, and different DAB modules will perform differently. But if the BER is low, then the differences in the AUDIO bitstream coming out of the decoder will be slight. And considering that 98% of stereo stations on DAB use 128kbps, which is known to provide poor audio quality, then I would suggest you're barking up the completely wrong tree. based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. OTOH if they all use identical, or functionally identically equivalent, circuits in every respect, there may be no such variations, so no such variables would affect what people get. In the absence of detailed information on this point, we can'r really say one way or the other. Can't say what one way or the other? Can't say which RX might function better than another in difficult reception situations of various kinds. Sorry, but I thought this would be clear from what I had written. You seem to be changing your tune. You originally said this: "If it is the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming." end of re-phrasing So far as I can tell, the above simply puts what I wrote before into rather more words. I hope it is now clear. Indeed, it seems to me to be no more than a fairly standard view of how engineered systems actually work in practice. The way I took what you'd written was that you were trying to suggest that we're hearing bad audio quality because we have poor reception or poor receivers. Am I right? No. I'm afraid that you had not understood what I wrote, THIS is what you wrote: "If it is the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming." Now you're changing your tune or you simply worded it badly in the first place. Which is it? and are jumping to an incorrect conclusion about what I had in mind. I trust this is now clear. No, it's very unclear, because you're changing what you originally said. However *some* people may not get the same results as others, thus until we have some information on that point we need to proceed with some caution. You say *some* people, so who are these people you were referring to when you said this: "If it is the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming." I'd love to know. Yeah, Jim, we've all got ****e reception with ****e receivers, and the audio quality is fantastic on everybody else's receivers because they're wonderful and they've got wonderful reception. There you go. That's what you wanted to hear, no? No. It might help you to discuss things if you took care not to jump to conclusions and then make such statements as the above. If you're changing your tune then say that you worded what you did badly, because as it stands it sounds very much like you're trying to cast doubt on the complaints about the audio quality that many of us have of DAB. You're looking at tiny imperfections and missing out the gross distortions. Not aware of any "suggestions" beyond what I wrote. But if you think there are, please start a new thread on that topic and explain what you had in mind. I can then either confirm what you thought I was "suggesting" or explain that I did not have it in mind. Oh, so now you want some suggestions? Really? I see. Good luck. My "luck" seems to have been mixed. :-) "Good" in that you said what you suspected, and I could then point out you have jumped to an erronious conclusion. I did not write what you seem to be assuming. Nor do I think it. You wrote this: "If it is the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming." Are you admitting that it was badly worded? As that sentence stands, it suggests that people that people may be making erroneous assessments of the audio quality. Don't tell me I'm jumping to conclusions, because it was YOUR wording that led me to those conclusions, because your wording is general rather than specific. "Bad" in that this thread has still be taken up with your concerns about the use of DAB by the BBC (and other broadcasters). Whereas my questions relate to the performance of RXs, not the behaviour of the BBC (and other broadcasters). Oh, so now the bit rate is irrelevant to the audio quality that we hear??? Try again from the beginning. In fact, try writing unambiguously what you're trying to investigate. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
Jim Lesurf wrote:
In article , DAB sounds worse than FM wrote: Jim Lesurf wrote: *If* it is the case that the performance of DAB RXs vary, and their sensitivities to various sorts of interference, etc, or poor reception conditions, etc, also vary, then it may follow that judgements based on measurements or listening using one RX in one set of circumstances might not always apply to the use of another, different, RX. Ditto for circumstances of use. Here's a good place to start: http://www.digitalradiotech.co.uk/im...io_quality.gif The curve for MP2 is labelled 'LII'. 128kbps is classified as "Annoying". 98% of stereo stationson DAB in the UK use 128kbps. Hope that helps. Afraid not. When you wrote the above you were apparently misunderstanding the questions I have been raising. I am not asking about bit rates or data reduction schemes. Nor about the subjective results of them. Start by explaining exactly what you mean by this: If it is the case that different DAB RXs give differing outputs when fed with the same DAB signal, then it may have some impact on the assessment of DAB that people keep making/assuming. In particular, explain what you meant by THIS: "the assessment of DAB that people keep making/assuming" Don't patronise me by telling me that I've mis-understood what you've written when what you've written is ambiguous. Okay? -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
DAB Performance of different makes?
John Phillips wrote:
On 2005-10-26, Dave Plowman (News) wrote: In article , tony sayer wrote: One of the things that excited me most about DAB when the specs were being drawn up was the alleged ability to choose whether or not you had compression at the receiver end. So one of my biggest disappointments is how this isn't actually the case for most stations in practice. Its not described as compression as such in broadcast circles. Audio "processing" is more the mark which of course includes compression, but the are other things which are done that would make your hair grey in a premature fashion...... It did/does include the ability to do a fairly straightforward dynamic range compression intended for use in cars, etc. However, most of the broadcasters have decided to do this at source these days. Which can often have a worse effect on sound quality than low bit rate DAB... Apart from the bad effects on music, doing the dynamic range compression at source is reported to have a significant effect on the MPEG layer 2 codec. "This audio codec, used in DAB, performs very poorly when processing dynamically compressed audio. typically 1 grading point below the figures quoted in section 1.2.3. When dynamic range compression is removed, the performance of DAB improves significantly." Dr David J M Robinson, Department of Electronic Systems Engineering, University of Essex. The grading points referred to are the oft quoted "not annoying", "slightly annoying", "annoying" etc. grading points. I think he gets much of his data from Soulodre et al, in the March 1998 volume of JAES. I've not seen him post for a week or so, but I'd be interested to see if David still thinks that audio processing degrades the audio quality by 1 diff-grade point. -- Steve - www.digitalradiotech.co.uk - Digital Radio News & Info Please sign the petition asking the BBC to provide better audio quality on its radio stations on DAB, Freeview, satellite and cable: http://tinyurl.com/a68e4 |
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