Minimum specs for a decent subwoofer ?

Hi. Please help this newbie with some reference point.
For the main purpose of watching movies (home-theater), in a very
small room, what specifications should I look for in a Subwoofer ?
I can't go over more details o the rest of equipment since I'm trying
to help my brother in building an affordable system.

I understand a decent Sub should be "active" (self-powered). So:

1- How many Watts RMS should it be rated, at minimum ? 100w, 150w,
200w,250w, ... ?

2- What frequency range should it cover for not too
unnatural/unpleasant sensation? 20hz, 30hz, 40hz, ...?

I guess some Subs that are too cheap enphasize the response in the
frequencies they handle, to generate some kind of impression effect
since they can't reach lower, is this so ?

3- Is there any JBL model that does a decent job ? Where I live, the
higher regarded names like Velodyne, Paradigm, etc, can't be found or
else cost too much for my budget. Waht about Infinity, Yamaha,
occasionally seen around ?
Again, this is not the US, where you can find other brands easily, and
the intention here is watching movies quite more than listening to
music.

Many thanks for reading.

wrote in message
...
Hi. Please help this newbie with some reference point.
For the main purpose of watching movies (home-theater), in a very
small room, what specifications should I look for in a Subwoofer ?
I can't go over more details o the rest of equipment since I'm trying
to help my brother in building an affordable system.

I understand a decent Sub should be "active" (self-powered). So:

1- How many Watts RMS should it be rated, at minimum ? 100w, 150w,
200w,250w, ... ?

Output power has little relevance, as driver efficiency, whether the cabinet
is sealed or ported, mutiple IB will also come into effect. Also required
SPL, material is being played (ie really low sub sonic bass), plus the size
of room another consideration



2- What frequency range should it cover for not too
unnatural/unpleasant sensation? 20hz, 30hz, 40hz, ...?

Better is lower, however also want a rough estimation just how loud at
required low frequency, and at what distortion. Most 8" subs will be able to
reproduce 20hz, but not at a very high SPL, or with low distortion. However
a high quality 12", 15" or 18" driver with 500W-2000W will most likely be
able to reproduce 100dB at 20hz at under 10%THD.

The overall frequency response is important too. Check it has +/-3dB. Avoid
anything with +/-6 or 10dB. Usually these subs are hyped up and overrated.

Look here for tested subs..

http://members.cox.net/frankcarter/T...Sub%20Data.htm

I guess some Subs that are too cheap enphasize the response in the
frequencies they handle, to generate some kind of impression effect
since they can't reach lower, is this so ?

Yes, usually have a mid-bass boost to give the effect of superior sound.
Also those with high THD seem to sound "nice" to unexperienced users.


3- Is there any JBL model that does a decent job ?

Quite a few use 18" JBL drivers in a multiple IB array, they do a very good
job. The seperate subs don't seem that highly regarded.

Where I live, the
higher regarded names like Velodyne, Paradigm, etc, can't be found or
else cost too much for my budget. Waht about Infinity, Yamaha,
occasionally seen around ?
Again, this is not the US, where you can find other brands easily, and
the intention here is watching movies quite more than listening to
music.

The Velodyne HGS/DD range are very good, but pricey. Paradigm Servo is a
great sub too. Don't bother with the PDR line. Consider PW-2200. Haven't
used Infinity. Avoid Yamaha.

I've got a SVS sub, and recommend them..

http://www.svsubwoofers.com/

wrote in message
...
Hi. Please help this newbie with some reference point.
For the main purpose of watching movies (home-theater), in a very
small room, what specifications should I look for in a Subwoofer ?
I can't go over more details o the rest of equipment since I'm trying
to help my brother in building an affordable system.

I understand a decent Sub should be "active" (self-powered). So:

1- How many Watts RMS should it be rated, at minimum ? 100w, 150w,
200w,250w, ... ?

Output power has little relevance, as driver efficiency, whether the cabinet
is sealed or ported, mutiple IB will also come into effect. Also required
SPL, material is being played (ie really low sub sonic bass), plus the size
of room another consideration



2- What frequency range should it cover for not too
unnatural/unpleasant sensation? 20hz, 30hz, 40hz, ...?

Better is lower, however also want a rough estimation just how loud at
required low frequency, and at what distortion. Most 8" subs will be able to
reproduce 20hz, but not at a very high SPL, or with low distortion. However
a high quality 12", 15" or 18" driver with 500W-2000W will most likely be
able to reproduce 100dB at 20hz at under 10%THD.

The overall frequency response is important too. Check it has +/-3dB. Avoid
anything with +/-6 or 10dB. Usually these subs are hyped up and overrated.

Look here for tested subs..

http://members.cox.net/frankcarter/T...Sub%20Data.htm

I guess some Subs that are too cheap enphasize the response in the
frequencies they handle, to generate some kind of impression effect
since they can't reach lower, is this so ?

Yes, usually have a mid-bass boost to give the effect of superior sound.
Also those with high THD seem to sound "nice" to unexperienced users.


3- Is there any JBL model that does a decent job ?

Quite a few use 18" JBL drivers in a multiple IB array, they do a very good
job. The seperate subs don't seem that highly regarded.

Where I live, the
higher regarded names like Velodyne, Paradigm, etc, can't be found or
else cost too much for my budget. Waht about Infinity, Yamaha,
occasionally seen around ?
Again, this is not the US, where you can find other brands easily, and
the intention here is watching movies quite more than listening to
music.

The Velodyne HGS/DD range are very good, but pricey. Paradigm Servo is a
great sub too. Don't bother with the PDR line. Consider PW-2200. Haven't
used Infinity. Avoid Yamaha.

I've got a SVS sub, and recommend them..

http://www.svsubwoofers.com/

wrote in message
...
Hi. Please help this newbie with some reference point.
For the main purpose of watching movies (home-theater), in a very
small room,

What's a small room? Dimensions. How loud do you listen to the system? Is
your current subwoofer calibrated hot, or would you set your new subwoofer
hot? (by that I mean the subwoofer is set louder than the others via the
test tones generated by the amp, and measured with a SPL meter. Usually
you'll set it slightly lower due to RS meter being off. Some bass heads set
it +6dB or even higher) If so you'll need a better subwoofer

what specifications should I look for in a Subwoofer ?
I can't go over more details o the rest of equipment since I'm trying
to help my brother in building an affordable system.

I understand a decent Sub should be "active" (self-powered).

By the way, you can buy very high quality passive subs too. Most people
associate passive subs to really cheap units like those in a HTIB.
Servodrive Contrabass is passive, so is the SVS B4+. Certainly high end
subs. What it means is you can decide what amplifier to use, you're not
limited and fixed to the sub panel (connections too). So you could buy a
cheap Samson S700 (2ch) for a budget passive dual sub system (ie DIY with
Peerless XLRS10 driver) or perhaps top end system with Crown K1 or K2 with
aforementioned Contrabass/B4+

What's his budget?

wrote in message
...
Hi. Please help this newbie with some reference point.
For the main purpose of watching movies (home-theater), in a very
small room,

What's a small room? Dimensions. How loud do you listen to the system? Is
your current subwoofer calibrated hot, or would you set your new subwoofer
hot? (by that I mean the subwoofer is set louder than the others via the
test tones generated by the amp, and measured with a SPL meter. Usually
you'll set it slightly lower due to RS meter being off. Some bass heads set
it +6dB or even higher) If so you'll need a better subwoofer

what specifications should I look for in a Subwoofer ?
I can't go over more details o the rest of equipment since I'm trying
to help my brother in building an affordable system.

I understand a decent Sub should be "active" (self-powered).

By the way, you can buy very high quality passive subs too. Most people
associate passive subs to really cheap units like those in a HTIB.
Servodrive Contrabass is passive, so is the SVS B4+. Certainly high end
subs. What it means is you can decide what amplifier to use, you're not
limited and fixed to the sub panel (connections too). So you could buy a
cheap Samson S700 (2ch) for a budget passive dual sub system (ie DIY with
Peerless XLRS10 driver) or perhaps top end system with Crown K1 or K2 with
aforementioned Contrabass/B4+

What's his budget?

wrote in message
...

3- Is there any JBL model that does a decent job ?

I have just bought the JBL 150P (Northridge series) subwoofer and it's a
stunning sub and great value for money. Plenty of slam and punch without
even a hint of distortion (105W RMS inbuilt amplifier, 225W peak), great for
music and movies and no 'humming' (digital inbuilt amplifier), I highly
recommend it.

--
Italo

wrote in message
...

3- Is there any JBL model that does a decent job ?

I have just bought the JBL 150P (Northridge series) subwoofer and it's a
stunning sub and great value for money. Plenty of slam and punch without
even a hint of distortion (105W RMS inbuilt amplifier, 225W peak), great for
music and movies and no 'humming' (digital inbuilt amplifier), I highly
recommend it.

--
Italo

"Nath" wrote :
Output power has little relevance, as driver efficiency, whether the cabinet
is sealed or ported, mutiple IB will also come into effect. Also required
SPL, material is being played (ie really low sub sonic bass), plus the size
of room another consideration

Many thanks for these tips.
Material being played should be rented DVDs and maybe mpeg-4 videos
with either AC-3 or mp3 audio.
The room I'd say is about 4 meters long by 6 meters wide and 2.5
meters high. I understand this is a very small room size for a HT
system and thus there shouldn't be a requirement for lots of power.
Could a 12-inch sub do a decent job regardless of how many Watts RMS
it is rated at ? How many Watts minimum in a real world?

The overall frequency response is important too. Check it has +/-3dB. Avoid
anything with +/-6 or 10dB.

OK. I'll keep a not of that too.

http://members.cox.net/frankcarter/T...Sub%20Data.htm
Yes, usually have a mid-bass boost to give the effect of superior sound.
Also those with high THD seem to sound "nice" to unexperienced users.

The site you provided suggests that the response of the lower end can
be compromised if it isn't as loud as the upper bass range (around
63hz). What would be an acceptable difference between the two ends ?
How can one minimize the effects of the above discrepancy, is there
any variable control that allows for some trimming-off of undesired
level emphasis ?

(JBL). The seperate subs don't seem that highly regarded.
The Velodyne HGS/DD range are very good, but pricey. Paradigm Servo is a
great sub too. Don't bother with the PDR line. Consider PW-2200. Haven't
used Infinity. Avoid Yamaha. I've got a SVS sub, and recommend them..

As I said, options aren't many. As far as models being sold nearby I
have seen these:
Acoustic Research AR PR1212
JBL E250P
Velodyne CHT-12

Are you familiar with any of these ? Could any do the job ?
Thanks, again,

"Nath" wrote :
Output power has little relevance, as driver efficiency, whether the cabinet
is sealed or ported, mutiple IB will also come into effect. Also required
SPL, material is being played (ie really low sub sonic bass), plus the size
of room another consideration

Many thanks for these tips.
Material being played should be rented DVDs and maybe mpeg-4 videos
with either AC-3 or mp3 audio.
The room I'd say is about 4 meters long by 6 meters wide and 2.5
meters high. I understand this is a very small room size for a HT
system and thus there shouldn't be a requirement for lots of power.
Could a 12-inch sub do a decent job regardless of how many Watts RMS
it is rated at ? How many Watts minimum in a real world?

The overall frequency response is important too. Check it has +/-3dB. Avoid
anything with +/-6 or 10dB.

OK. I'll keep a not of that too.

http://members.cox.net/frankcarter/T...Sub%20Data.htm
Yes, usually have a mid-bass boost to give the effect of superior sound.
Also those with high THD seem to sound "nice" to unexperienced users.

The site you provided suggests that the response of the lower end can
be compromised if it isn't as loud as the upper bass range (around
63hz). What would be an acceptable difference between the two ends ?
How can one minimize the effects of the above discrepancy, is there
any variable control that allows for some trimming-off of undesired
level emphasis ?

(JBL). The seperate subs don't seem that highly regarded.
The Velodyne HGS/DD range are very good, but pricey. Paradigm Servo is a
great sub too. Don't bother with the PDR line. Consider PW-2200. Haven't
used Infinity. Avoid Yamaha. I've got a SVS sub, and recommend them..

As I said, options aren't many. As far as models being sold nearby I
have seen these:
Acoustic Research AR PR1212
JBL E250P
Velodyne CHT-12

Are you familiar with any of these ? Could any do the job ?
Thanks, again,

wrote in message
m...

Many thanks for these tips.
Material being played should be rented DVDs and maybe mpeg-4 videos
with either AC-3 or mp3 audio.
The room I'd say is about 4 meters long by 6 meters wide and 2.5
meters high.

A 20-39 PCi would be plenty in that sized room. I use a 20-39 PC Plus in a
4m x 4m room :-) overkill I know, but I wasn't sure just how much headroom
the Plus has over my Rel Storm. I'd say quite a bit now ;-)

http://www.svsubwoofers.com/subs_pci_20-39.htm

Looking at £480 all-in price, and with the good exchance rate (1.7) it's a
good time to buy.

SVS have great customer service. Contact Tom V at SVS. He will not oversell
you, or tell you BS, in fact if you mention some other subs he sometimes
will recommend them over his own products (ie a Canadian can get a Servo 15
at a much better price compared to it's SVS competitor, the PCi)

I understand this is a very small room size for a HT
system and thus there shouldn't be a requirement for lots of power.
Could a 12-inch sub do a decent job regardless of how many Watts RMS
it is rated at ?

A good quality subwoofer should do fine, a decent 10 or 12". Again watts RMS
is another issue. A ported efficient large box subwoofer would require much
less power with no EQ, comapared to a small sealed box with a high amount of
EQ to correct the driver/cab issues. If you've got the money though, and
want lots of headroom (or like it loud) then buy the best subwoofer you can
afford, it's definetly worth spending £100-£200 more from a budget model to
one-up.

For example there's a huge multiple IB subwoofer with something like 32 x
18" drivers, a 18W tube amp is being used to drive it.

Compare a SVS PCi (300W) versus a Sunfire Junior (1.5KW) The Sunfire has a
much bigger amp. But in reality the SVS goes much louder, plays cleaner,
plays lower, with much lower distortion. The SVS is also cheaper too.

How many Watts minimum in a real world?

Can't answer that.

The site you provided suggests that the response of the lower end can
be compromised if it isn't as loud as the upper bass range (around
63hz). What would be an acceptable difference between the two ends ?
How can one minimize the effects of the above discrepancy, is there
any variable control that allows for some trimming-off of undesired
level emphasis ?

If you want a subwoofer to be flat(er), then consider a Behringer Feedback
Destroyer Pro. It's also a 12 band stereo parametric EQ. Read up here..you
might not need a BFD but it's worth considering later on. About £100.

http://www.snapbug.ws/bfd.htm

As I said, options aren't many. As far as models being sold nearby I
have seen these:
Acoustic Research AR PR1212
JBL E250P
Velodyne CHT-12

I would consider that SVS above that list. From other users the PCi is
superior to that of the CHT-12. Haven't really heard much about the JBL or
AR.

I take it you're looking around £350 for a subwoofer? What's the rest of the
system?


Are you familiar with any of these ? Could any do the job ?
Thanks, again,

Do the job, yes. So could a mid-range Yamaha subwoofer or Rel Quake. But do
you want something to "do the job" or do you want a great sounding
subwoofer?