Distortion of sound with music channels
 

I an using a Portland (Labgear) Freeview box which works great apart
from lots of distortion on some of the music channels (things like
Kiss & Kerang). The sound is like you would get if an FM radio was not
tuned properly with lots of sibilance. All the other TV channels sound
fine & music on TV channels is OK. I have tried differnent volume
settings with no change. Does anyone have any ideas. What sort of
signal strength & SNR levels should I need for good qualiy as the
strength is between 78 on channel 21 & 66 on channel 42. The SNR is
between 25 & 27 all from Bilsdale

In article , John
writes
I an using a Portland (Labgear) Freeview box which works great apart
from lots of distortion on some of the music channels (things like
Kiss & Kerang). The sound is like you would get if an FM radio was not
tuned properly with lots of sibilance. All the other TV channels sound
fine & music on TV channels is OK. I have tried differnent volume
settings with no change. Does anyone have any ideas. What sort of
signal strength & SNR levels should I need for good qualiy as the
strength is between 78 on channel 21 & 66 on channel 42. The SNR is
between 25 & 27 all from Bilsdale

The audio quality on some services like Kerrang isn't noted for the
shall we say "fi"....
--
Tony Sayer

John said the following on 2005-04-16 10:23:
I an using a Portland (Labgear) Freeview box which works great apart
from lots of distortion on some of the music channels (things like
Kiss & Kerang). The sound is like you would get if an FM radio was not
tuned properly with lots of sibilance. All the other TV channels sound
fine & music on TV channels is OK. I have tried differnent volume
settings with no change. Does anyone have any ideas. What sort of
signal strength & SNR levels should I need for good qualiy as the
strength is between 78 on channel 21 & 66 on channel 42. The SNR is
between 25 & 27 all from Bilsdale

All the Emap radio services (epecially Heat and Mojo) are distored on
Freeview and DAB (and presumably Dsat).

On Sat, 16 Apr 2005 13:21:51 GMT, Kev wrote:

John said the following on 2005-04-16 10:23:
I an using a Portland (Labgear) Freeview box which works great apart
from lots of distortion on some of the music channels (things like
Kiss & Kerang). The sound is like you would get if an FM radio was not
tuned properly with lots of sibilance. All the other TV channels sound
fine & music on TV channels is OK. I have tried differnent volume
settings with no change. Does anyone have any ideas. What sort of
signal strength & SNR levels should I need for good qualiy as the
strength is between 78 on channel 21 & 66 on channel 42. The SNR is
between 25 & 27 all from Bilsdale

All the Emap radio services (epecially Heat and Mojo) are distored on
Freeview and DAB (and presumably Dsat).

Any Idea why

John said the following on 2005-04-16 15:06:
On Sat, 16 Apr 2005 13:21:51 GMT, Kev wrote:


John said the following on 2005-04-16 10:23:

I an using a Portland (Labgear) Freeview box which works great apart
from lots of distortion on some of the music channels (things like
Kiss & Kerang). The sound is like you would get if an FM radio was not
tuned properly with lots of sibilance. All the other TV channels sound
fine & music on TV channels is OK. I have tried differnent volume
settings with no change. Does anyone have any ideas. What sort of
signal strength & SNR levels should I need for good qualiy as the
strength is between 78 on channel 21 & 66 on channel 42. The SNR is
between 25 & 27 all from Bilsdale

All the Emap radio services (epecially Heat and Mojo) are distored on
Freeview and DAB (and presumably Dsat).


Any Idea why
Emap say they are set up correctly
(But this is the group that speed up all the songs on the FM ILRs and
think 64kbps (i.e. sub-AM quality) stations are acceptible)

Kev wrote:
John said the following on 2005-04-16 15:06:
On Sat, 16 Apr 2005 13:21:51 GMT, Kev wrote:


John said the following on 2005-04-16 10:23:

I an using a Portland (Labgear) Freeview box which works great
apart from lots of distortion on some of the music channels
(things like Kiss & Kerang). The sound is like you would get if an
FM radio was not tuned properly with lots of sibilance. All the
other TV channels sound fine & music on TV channels is OK. I have
tried differnent volume settings with no change. Does anyone have
any ideas. What sort of signal strength & SNR levels should I need
for good qualiy as the strength is between 78 on channel 21 & 66
on channel 42. The SNR is between 25 & 27 all from Bilsdale

All the Emap radio services (epecially Heat and Mojo) are distored
on Freeview and DAB (and presumably Dsat).


Any Idea why
Emap say they are set up correctly
(But this is the group that speed up all the songs on the FM ILRs and
think 64kbps (i.e. sub-AM quality) stations are acceptible)

It's called Optimod. A system designed to make stations sound 'louder' by
reducing dynamic range and raising audio levels of whatever audio frequencies
are left. Problem is, a lot of music companies have cottoned on to this stupid
idea and started producing CDs that don't just *sound* louder, but actually
*are* louder, to the extent that there is noticeable clipping and distortion on
playback. Combine this with the optimodded audio output on stations like Kerrang
and a bitrate that offers limited audio headroom in the first place and you got
audio playback that sounds loud, clipped, distorted and washed out. On cable,
almost all radio stations are distorted in this way and it's beginning to go
this way on my old OnDigital box as well, no matter what volume setting I have
it at. This is supposed to be the 'future' of radio too!

Well, at least there's FM...

Paul.

In article , Paul Evans uknorthernerSPA
writes
Kev wrote:
John said the following on 2005-04-16 15:06:
On Sat, 16 Apr 2005 13:21:51 GMT, Kev wrote:


John said the following on 2005-04-16 10:23:

I an using a Portland (Labgear) Freeview box which works great
apart from lots of distortion on some of the music channels
(things like Kiss & Kerang). The sound is like you would get if an
FM radio was not tuned properly with lots of sibilance. All the
other TV channels sound fine & music on TV channels is OK. I have
tried differnent volume settings with no change. Does anyone have
any ideas. What sort of signal strength & SNR levels should I need
for good qualiy as the strength is between 78 on channel 21 & 66
on channel 42. The SNR is between 25 & 27 all from Bilsdale

All the Emap radio services (epecially Heat and Mojo) are distored
on Freeview and DAB (and presumably Dsat).


Any Idea why
Emap say they are set up correctly
(But this is the group that speed up all the songs on the FM ILRs and
think 64kbps (i.e. sub-AM quality) stations are acceptible)

It's called Optimod. A system designed to make stations sound 'louder' by
reducing dynamic range and raising audio levels of whatever audio frequencies
are left. Problem is, a lot of music companies have cottoned on to this stupid
idea and started producing CDs that don't just *sound* louder, but actually
*are* louder, to the extent that there is noticeable clipping and distortion on
playback. Combine this with the optimodded audio output on stations like Kerrang
and a bitrate that offers limited audio headroom in the first place and you got
audio playback that sounds loud, clipped, distorted and washed out. On cable,
almost all radio stations are distorted in this way and it's beginning to go
this way on my old OnDigital box as well, no matter what volume setting I have
it at. This is supposed to be the 'future' of radio too!

Well, at least there's FM...

Paul.



Which is Optimoded well to. What doesn't help is the sourcing of
materiel from reduced bitrate hard disk players and the other cross
contaminants for sample rate conversion etc, all add together;(....
--
Tony Sayer

Paul Evans said the following on 2005-04-16 18:25:
It's called Optimod. A system designed to make stations sound
'louder' by
reducing dynamic range and raising audio levels of whatever audio frequencies
are left. Problem is, a lot of music companies have cottoned on to this stupid
idea and started producing CDs that don't just *sound* louder, but actually
*are* louder, to the extent that there is noticeable clipping and distortion on
playback. Combine this with the optimodded audio output on stations like Kerrang
and a bitrate that offers limited audio headroom in the first place and you got
audio playback that sounds loud, clipped, distorted and washed out. On cable,
almost all radio stations are distorted in this way and it's beginning to go
this way on my old OnDigital box as well, no matter what volume setting I have
it at. This is supposed to be the 'future' of radio too!

Well, at least there's FM...

Which is screwed as well, if your favourite station has been Emapped

That's
Kiss and Magic in London
Metro and TFM in the North East
Viking, Hallam and Aire in Yorkshire
Rock, City and Key in the North West
Kerrang in the West Midlands

Magic must be the only emap station where the songs arn't speeded up.

Welcome to 'over-compression', something audio pro's have been complaining
about for years, but now it's getting silly, to the point when Joe Public
notices.
All CD's are compressed way to far these days to make them sound 'louder',
then radio stations compress them even further to make their station louder
on the dial. Obviously this doesn't work, and just ends up sucking all the
feel out of the music, and when it goes too far the compressors actually
distort the sound, because they are being driven too far. Then couple that
with a low bit-rate data compression leads to a truly awful sound, and it's
only going to get worse!!


"John" wrote in message
...
I an using a Portland (Labgear) Freeview box which works great apart
from lots of distortion on some of the music channels (things like
Kiss & Kerang). The sound is like you would get if an FM radio was not
tuned properly with lots of sibilance. All the other TV channels sound
fine & music on TV channels is OK. I have tried differnent volume
settings with no change. Does anyone have any ideas. What sort of
signal strength & SNR levels should I need for good qualiy as the
strength is between 78 on channel 21 & 66 on channel 42. The SNR is
between 25 & 27 all from Bilsdale