Connecting subwoofers to a 2-channel audio amp.
 

Hi guys,

I was recently caught up with a friend who is planning to upgrade his
main speakers to one with responses between 20Hz-20KHz.

I was told that one of the sales guys mentioned an alternative - Buy a
good pair subwoofers to support the pair of lovely Whatmough (40
HZ-20KHz) mains my friend already has.

I was wondering how could subwoofers be connected to a two channel amp
as it is primarily a 5-channel equipment. The amp is a 20yrs old denon
with phono inputs, CD direct etc.

Is this sales guy just bull-****ting or can this really be done?

cheers

Max

Connecting subwoofers to a 2-channel audio amp.
 

"max graff" wrote in message
ups.com...


** Groper from Hell alert !


I was recently caught up with a friend who is planning to upgrade his
main speakers to one with responses between 20Hz-20KHz.

I was told that one of the sales guys mentioned an alternative - Buy a
good pair subwoofers to support the pair of lovely Whatmough (40
HZ-20KHz) mains my friend already has.

I was wondering how could subwoofers be connected to a two channel amp
as it is primarily a 5-channel equipment. The amp is a 20yrs old denon
with phono inputs, CD direct etc.

Is this sales guy just bull-****ting or can this really be done?



** So you have never heard of an "active" sub woofer ??

Use Google - there are hundreds of them on the market.,




....... Phil

Connecting subwoofers to a 2-channel audio amp.
 

Phil Alison wrote:

I was wondering how could subwoofers be connected to a two channel
amp
as it is primarily a 5-channel equipment. The amp is a 20yrs old
denon
with phono inputs, CD direct etc.

Is this sales guy just bull-****ting or can this really be done?

** So you have never heard of an "active" sub woofer ??

Needs line level output/s from the amp? Maybe not got?

Ian

"Phil Allison" wrote in message
...

"max graff" wrote in message
ups.com...


** Groper from Hell alert !


I was recently caught up with a friend who is planning to upgrade
his
main speakers to one with responses between 20Hz-20KHz.

I was told that one of the sales guys mentioned an alternative -
Buy a
good pair subwoofers to support the pair of lovely Whatmough (40
HZ-20KHz) mains my friend already has.


Use Google - there are hundreds of them on the market.,




...... Phil

Connecting subwoofers to a 2-channel audio amp.
 

"Ian Iveson the ****ing Idiot "



Needs line level output/s from the amp? Maybe not got?


** Speaker level is provided for in nearly all cases.





........ Phil

Connecting subwoofers to a 2-channel audio amp.
 

Hi Phil,

Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.

Cheers

Max

Connecting subwoofers to a 2-channel audio amp.
 

"max graff" wrote in message
oups.com...


** Groper with NO USENET CLUE alert !



Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.



** You connect them as shown in the operator's manual !!!!

Could be linked by RCA leads to the pre-amp outputs on the amp or via the
speaker outputs.

Commonly, active subs are simply linked with short wires to the existing
speakers.


BTW:


Do NOT post in "mid air" like this !!!!!!!!!!!!!!!!!!!!

ALWAYS quote the post and poster you are responding to.




........ Phil

Connecting subwoofers to a 2-channel audio amp.
 

max graff wrote:

Hi Phil,

Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.

Connect them to the two channels !

Graham

Connecting subwoofers to a 2-channel audio amp.
 

Eeyore wrote:
max graff wrote:

Hi Phil,

Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.

Connect them to the two channels !

Graham

Graham,

You mean in series with the mains?

Connecting subwoofers to a 2-channel audio amp.
 

max graff wrote:

Eeyore wrote:
max graff wrote:

Hi Phil,

Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.

Connect them to the two channels !

Graham

Graham,

You mean in series with the mains?

They would go in parallel but you need a crossover somewhere too.

I suggest you listen to the nice man in the shop. He seems to know what he's
talkking about.

Graham

Connecting subwoofers to a 2-channel audio amp.
 

"max graff" wrote in message
ups.com...
Hi guys,

I was recently caught up with a friend who is planning to upgrade his
main speakers to one with responses between 20Hz-20KHz.


:-)

Nice theory......

(The 'audible range' is more 16 Hz - 16 kHz, btw....)



I was told that one of the sales guys mentioned an alternative - Buy a
good pair subwoofers to support the pair of lovely Whatmough (40
HZ-20KHz) mains my friend already has.

I was wondering how could subwoofers be connected to a two channel amp
as it is primarily a 5-channel equipment. The amp is a 20yrs old denon
with phono inputs, CD direct etc.

Is this sales guy just bull-****ting or can this really be done?


Yes, see:

http://www.apah69.dsl.pipex.com/show/subbie.JPG


For how it goes....

But you don't need 2 subs, the sound is omnidirectional at those
frequencies - apart from the unnecessary expense, using 2 subs will give no
benefit and might well allow problems to creep in if they are not perfectly
matched...

Connecting subwoofers to a 2-channel audio amp.
 

On 11 Jan 2007 23:30:11 -0800, "max graff" wrote:


Eeyore wrote:
max graff wrote:

Hi Phil,

Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.

Connect them to the two channels !

Graham

Graham,

You mean in series with the mains?

Not exactly. What your friend needs is 1 or 2 subs with a
speaker-level crossover. Then, he can connect the main amp outputs to
the sub(s) and then connect the main L/R speakers to the crossover
outputs on the subs. Thus, the crossovers will divide the frequency
spectrum appropriately.

For this, I prefer powered (built-in amp) subs so that they do not
draw any significant power from the main amp. Whether he needs one or
two depends on how low he can make the crossover and his room
arrangement/acoustics. Most can do just fine with one better sub than
two cheaper ones. I personally recommend those with equalization to
compensate somewhat for room modes.

Kal

Connecting subwoofers to a 2-channel audio amp.
 

On 12 Jan 2007 14:02:58 GMT, Kalman Rubinson wrote:

On 11 Jan 2007 23:30:11 -0800, "max graff" wrote:


Eeyore wrote:
max graff wrote:

Hi Phil,

Yes I am aware of 'active' subbys and have a couple at my place.Al of
them however have been connected to my Marantz 6.1 integrated amp .

In my friend's case the only two speaker outputs are left and right.
Hence my question how do I get subbys to work on a two channel amp.

Connect them to the two channels !

Graham

Graham,

You mean in series with the mains?

Not exactly. What your friend needs is 1 or 2 subs with a
speaker-level crossover. Then, he can connect the main amp outputs to
the sub(s) and then connect the main L/R speakers to the crossover
outputs on the subs. Thus, the crossovers will divide the frequency
spectrum appropriately.

For this, I prefer powered (built-in amp) subs so that they do not
draw any significant power from the main amp. Whether he needs one or
two depends on how low he can make the crossover and his room
arrangement/acoustics. Most can do just fine with one better sub than
two cheaper ones. I personally recommend those with equalization to
compensate somewhat for room modes.

Kal

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

d

--
Pearce Consulting
http://www.pearce.uk.com

Connecting subwoofers to a 2-channel audio amp.
 

"Kalman Rubinson = Brainless Pile of Kike **** "


Not exactly. What your friend needs is 1 or 2 subs with a
speaker-level crossover. Then, he can connect the main amp outputs to
the sub(s) and then connect the main L/R speakers to the crossover
outputs on the subs. Thus, the crossovers will divide the frequency
spectrum appropriately.


** No such passive sub x-over * really * exists - you PITA ****wit.

Any specs or web pages that suggest otherwise a total FICTION !!



For this, I prefer powered (built-in amp) subs so that they do not
draw any significant power from the main amp


** Which UTTERLY contradicts your previous para.


APPARENTLY: There is absolutely no upper limit to the * asinine *****
that know nothing poseurs like this cretin will attempt promulgate.

But I am more than happy to stick a giant spanner in the dumb ****'s works.





......... Phil

Connecting subwoofers to a 2-channel audio amp.
 

"Don Pearce ****ing MORON "


I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible.


** APPARENTLY: There is absolutely no upper limit to the * asinine *****
that know nothing poseurs like this cretin will attempt promulgate.

But I am more than happy to stick a giant spanner in the dumb ****'s works.


Provided there is
very little distortion and the crossover frequency is sensible,


** Reads like some dumb**** " get out of jail free " card.



there
is no benefit to having a pair of subs - you can't locate the sound
anyway.


** ROTFL.

What a deceitful STRAW MAN !!!

What a ****ing dickwad moron propped it up.



Pearce ****sulting
http://www.pearce.uk.com


** Avoid this ASD ****ed pommy FAKE at all costs.





......... Phil

Connecting subwoofers to a 2-channel audio amp.
 

Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

Oh yes you can !

That's just an old wives' tale.

Graham

Connecting subwoofers to a 2-channel audio amp.
 

On Fri, 12 Jan 2007 18:43:39 +0000, Eeyore
wrote:



Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

Oh yes you can !

That's just an old wives' tale.


Ok - I'm an old wife then, cos I can't. Nor could the BBC acoustic
research chaps at Kingswood Warren when they demonstrated their ultra
wideband system to me - the sub was about thirty feet from the main
speakers and neither they nor I could locate it aurally, even though
we could see where it was.

d


--
Pearce Consulting
http://www.pearce.uk.com

Connecting subwoofers to a 2-channel audio amp.
 

Eeyore wrote:

Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

Oh yes you can !

That's just an old wives' tale.

Graham


I'm not so sure. I did some tests a couple of months ago after reading
that in the early days of stereo, Philips reckoned that anything below
200 Hz was non-directional, and consequently, a sub and two satellites
was perfectly acceptable for stereo. EMI insisted on two full-range
loudspeakers.

Using sine waves into left only, right only or equally into both, below
220 Hz it was increasingly difficult to decide which was playing, and
impossible below 150 Hz. That of course is in my room, and other rooms
may be different.

However, when using a single subwoofer located to the right of the
right-hand 'speaker and with a crossover of 70Hz, it was disturbing to
hear the extreme bass separate from the 'speakers, possibly as a result
of hearing harmonics from the sub. The disturbing effect went away when
the sub was positioned between the main 'speakers.

I currently use two subs to fill in the bottom half-octave below my main
'speakers, and I have them located as close as possible to the mains to
create effectively a pair of larger 'speakers. Works for me.

S.

Connecting subwoofers to a 2-channel audio amp.
 

"Serge Auckland" wrote in message
...
Eeyore wrote:

Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

Oh yes you can !

That's just an old wives' tale.

Graham


I'm not so sure. I did some tests a couple of months ago after reading
that in the early days of stereo, Philips reckoned that anything below 200
Hz was non-directional, and consequently, a sub and two satellites was
perfectly acceptable for stereo. EMI insisted on two full-range
loudspeakers.

Using sine waves into left only, right only or equally into both, below
220 Hz it was increasingly difficult to decide which was playing, and
impossible below 150 Hz. That of course is in my room, and other rooms may
be different.

However, when using a single subwoofer located to the right of the
right-hand 'speaker and with a crossover of 70Hz, it was disturbing to
hear the extreme bass separate from the 'speakers, possibly as a result of
hearing harmonics from the sub. The disturbing effect went away when the
sub was positioned between the main 'speakers.

I currently use two subs to fill in the bottom half-octave below my main
'speakers, and I have them located as close as possible to the mains to
create effectively a pair of larger 'speakers. Works for me.



This is interesting. This very thread has prompted me to set the 'sub ball'
rolling (finally) and I've scrounged a sub to play with for a few days:

http://www.apah69.dsl.pipex.com/show/subbie2.JPG

http://www.apah69.dsl.pipex.com/show/subbie3.JPG


....with a view to building one (or one like it) and am considering these
atm:

http://www.bkelec.com/HiFi/Sub_Woofers.htm

http://www.iplacoustics.co.uk/SW5%20...0subwoofer.htm


...unless anyone knows better?

But my point is that there is no way of locating the single sub by ear in my
small room and, as the sub in the photos (BK Electronics) has a *variable*
phase adjustment between 0 and 180 deg, is there not a danger of phase
cancellation with two subs, given that they seem to need a lot of adjustment
and faffing with to suit the various different types of music....??

IOW, is a pair of subs a possible complication that might be best *not*
bothered with....??

Connecting subwoofers to a 2-channel audio amp.
 

Lads,

Thanks a lot to all for your comments and valued inputs. This has
helped me a great deal personally and has saved my mate a lot of money.

Cheers

Max

Connecting subwoofers to a 2-channel audio amp.
 

Phil Allison wrote:
"Kalman Rubinson = Brainless Pile of Kike **** "


Not exactly. What your friend needs is 1 or 2 subs with a
speaker-level crossover. Then, he can connect the main amp outputs to
the sub(s) and then connect the main L/R speakers to the crossover
outputs on the subs. Thus, the crossovers will divide the frequency
spectrum appropriately.


** No such passive sub x-over * really * exists - you PITA ****wit.


Well that's EXACTLY how my Harbeth subs work.

Now who's brainless, gob****e?

Roy.

Connecting subwoofers to a 2-channel audio amp.
 

Keith G wrote:
"Serge Auckland" wrote in message
...
Eeyore wrote:
Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.
Oh yes you can !

That's just an old wives' tale.

Graham

I'm not so sure. I did some tests a couple of months ago after reading
that in the early days of stereo, Philips reckoned that anything below 200
Hz was non-directional, and consequently, a sub and two satellites was
perfectly acceptable for stereo. EMI insisted on two full-range
loudspeakers.

Using sine waves into left only, right only or equally into both, below
220 Hz it was increasingly difficult to decide which was playing, and
impossible below 150 Hz. That of course is in my room, and other rooms may
be different.

However, when using a single subwoofer located to the right of the
right-hand 'speaker and with a crossover of 70Hz, it was disturbing to
hear the extreme bass separate from the 'speakers, possibly as a result of
hearing harmonics from the sub. The disturbing effect went away when the
sub was positioned between the main 'speakers.

I currently use two subs to fill in the bottom half-octave below my main
'speakers, and I have them located as close as possible to the mains to
create effectively a pair of larger 'speakers. Works for me.



This is interesting. This very thread has prompted me to set the 'sub ball'
rolling (finally) and I've scrounged a sub to play with for a few days:

http://www.apah69.dsl.pipex.com/show/subbie2.JPG

http://www.apah69.dsl.pipex.com/show/subbie3.JPG


...with a view to building one (or one like it) and am considering these
atm:

http://www.bkelec.com/HiFi/Sub_Woofers.htm

http://www.iplacoustics.co.uk/SW5%20...0subwoofer.htm


..unless anyone knows better?

But my point is that there is no way of locating the single sub by ear in my
small room and, as the sub in the photos (BK Electronics) has a *variable*
phase adjustment between 0 and 180 deg, is there not a danger of phase
cancellation with two subs, given that they seem to need a lot of adjustment
and faffing with to suit the various different types of music....??

IOW, is a pair of subs a possible complication that might be best *not*
bothered with....??




Should work wonderfully well using one of your 4W SETs............

Seriously, in your room, a single sub should be more than ample. As to
phasing, I really don't understand the point of a variable phase
control. 0 & 180 switched should be provided to phase up the sub with
the mains (which hopefully will be in phase with each other), but apart
from that, I can't see it's possible to match the phase of the main LF,
as it will be frequency dependant. As you suggest, with two subs, trying
to get the phase right would be a nightmare.

Other controls needed are a crossover frequency selector and a level
control. Ideally, if the main speakers are small (say don't go below
70Hz) then the extreme bass should be rolled-off to the mains
considerably improving their power handling and lowering distortion.



S.

Connecting subwoofers to a 2-channel audio amp.
 

Roy wrote:

Phil Allison wrote:

"Kalman Rubinson = Brainless Pile of Kike **** "


Not exactly. What your friend needs is 1 or 2 subs with a
speaker-level crossover. Then, he can connect the main amp outputs to
the sub(s) and then connect the main L/R speakers to the crossover
outputs on the subs. Thus, the crossovers will divide the frequency
spectrum appropriately.



** No such passive sub x-over * really * exists - you PITA
****wit.


Well that's EXACTLY how my Harbeth subs work.

Now who's brainless, gob****e?

Which model of Harbeth subwoofer do you have?

--
Eiron.

Connecting subwoofers to a 2-channel audio amp.
 

Guys,

I am not sure if Whatmough sub's are available in UK.

I strongly suggest having a look at them. Its not the patriotic Aussie
in me blantantly favoring it, but they are really good. I have used
their entire range of speakers for almost 6 years now. Here is the
configuration for the Tornado range I own -

Configuration 1x300mm (12") cellulose fibre cone with a very long throw
suspension. This driver has a rubber surround and high temperature
voice coil.
Enclosure 25mm thick cabinet walls, fully braced bass enclosure with
bass reflex loading.
Amplifier 240 Watts continuous power output. Line and speaker level
outputs and inputs. Auto on/off switch. Thermal output protection.
Continuously variable gain (volume) control.
Electronic low-pass crossover from 40 to 160Hz.
Bass Extension 22Hz -3dB, usable bass to well below 20Hz
Average levels of 50 Watts.
Dimensions 500H x 470W x 570D mm.
Weight 30kg
Finish Bubinga real wood veneer

More information on their entire range is available on -

http://whatmough-whise.com/subwoofers.htm

I had the pleasure to meet up with the chief designer of the Impulse
range and understand the philosophy behind the design. Bloody awesome.
Cheers

Max

Keith G wrote:
"Serge Auckland" wrote in message
...
Eeyore wrote:

Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

Oh yes you can !

That's just an old wives' tale.

Graham


I'm not so sure. I did some tests a couple of months ago after reading
that in the early days of stereo, Philips reckoned that anything below 200
Hz was non-directional, and consequently, a sub and two satellites was
perfectly acceptable for stereo. EMI insisted on two full-range
loudspeakers.

Using sine waves into left only, right only or equally into both, below
220 Hz it was increasingly difficult to decide which was playing, and
impossible below 150 Hz. That of course is in my room, and other rooms may
be different.

However, when using a single subwoofer located to the right of the
right-hand 'speaker and with a crossover of 70Hz, it was disturbing to
hear the extreme bass separate from the 'speakers, possibly as a result of
hearing harmonics from the sub. The disturbing effect went away when the
sub was positioned between the main 'speakers.

I currently use two subs to fill in the bottom half-octave below my main
'speakers, and I have them located as close as possible to the mains to
create effectively a pair of larger 'speakers. Works for me.



This is interesting. This very thread has prompted me to set the 'sub ball'
rolling (finally) and I've scrounged a sub to play with for a few days:

http://www.apah69.dsl.pipex.com/show/subbie2.JPG

http://www.apah69.dsl.pipex.com/show/subbie3.JPG


...with a view to building one (or one like it) and am considering these
atm:

http://www.bkelec.com/HiFi/Sub_Woofers.htm

http://www.iplacoustics.co.uk/SW5%20...0subwoofer.htm


..unless anyone knows better?

But my point is that there is no way of locating the single sub by ear in my
small room and, as the sub in the photos (BK Electronics) has a *variable*
phase adjustment between 0 and 180 deg, is there not a danger of phase
cancellation with two subs, given that they seem to need a lot of adjustment
and faffing with to suit the various different types of music....??

IOW, is a pair of subs a possible complication that might be best *not*
bothered with....??

Connecting subwoofers to a 2-channel audio amp.
 

correction ... i own the Typhoon range more information is available on
-

http://www.pymblehifi.com.au/Whatmough%20Subwoofers.htm


max graff wrote:
Guys,

I am not sure if Whatmough sub's are available in UK.

I strongly suggest having a look at them. Its not the patriotic Aussie
in me blantantly favoring it, but they are really good. I have used
their entire range of speakers for almost 6 years now. Here is the
configuration for the Tornado range I own -

Configuration 1x300mm (12") cellulose fibre cone with a very long throw
suspension. This driver has a rubber surround and high temperature
voice coil.
Enclosure 25mm thick cabinet walls, fully braced bass enclosure with
bass reflex loading.
Amplifier 240 Watts continuous power output. Line and speaker level
outputs and inputs. Auto on/off switch. Thermal output protection.
Continuously variable gain (volume) control.
Electronic low-pass crossover from 40 to 160Hz.
Bass Extension 22Hz -3dB, usable bass to well below 20Hz
Average levels of 50 Watts.
Dimensions 500H x 470W x 570D mm.
Weight 30kg
Finish Bubinga real wood veneer

More information on their entire range is available on -

http://whatmough-whise.com/subwoofers.htm

I had the pleasure to meet up with the chief designer of the Impulse
range and understand the philosophy behind the design. Bloody awesome.
Cheers

Max

Keith G wrote:
"Serge Auckland" wrote in message
...
Eeyore wrote:

Don Pearce wrote:

I would add that finding an ideal position for one sub is hard, and
right positions for two are near enough impossible. Provided there is
very little distortion and the crossover frequency is sensible, there
is no benefit to having a pair of subs - you can't locate the sound
anyway.

Oh yes you can !

That's just an old wives' tale.

Graham


I'm not so sure. I did some tests a couple of months ago after reading
that in the early days of stereo, Philips reckoned that anything below 200
Hz was non-directional, and consequently, a sub and two satellites was
perfectly acceptable for stereo. EMI insisted on two full-range
loudspeakers.

Using sine waves into left only, right only or equally into both, below
220 Hz it was increasingly difficult to decide which was playing, and
impossible below 150 Hz. That of course is in my room, and other rooms may
be different.

However, when using a single subwoofer located to the right of the
right-hand 'speaker and with a crossover of 70Hz, it was disturbing to
hear the extreme bass separate from the 'speakers, possibly as a result of
hearing harmonics from the sub. The disturbing effect went away when the
sub was positioned between the main 'speakers.

I currently use two subs to fill in the bottom half-octave below my main
'speakers, and I have them located as close as possible to the mains to
create effectively a pair of larger 'speakers. Works for me.



This is interesting. This very thread has prompted me to set the 'sub ball'
rolling (finally) and I've scrounged a sub to play with for a few days:

http://www.apah69.dsl.pipex.com/show/subbie2.JPG

http://www.apah69.dsl.pipex.com/show/subbie3.JPG


...with a view to building one (or one like it) and am considering these
atm:

http://www.bkelec.com/HiFi/Sub_Woofers.htm

http://www.iplacoustics.co.uk/SW5%20...0subwoofer.htm


..unless anyone knows better?

But my point is that there is no way of locating the single sub by ear in my
small room and, as the sub in the photos (BK Electronics) has a *variable*
phase adjustment between 0 and 180 deg, is there not a danger of phase
cancellation with two subs, given that they seem to need a lot of adjustment
and faffing with to suit the various different types of music....??

IOW, is a pair of subs a possible complication that might be best *not*
bothered with....??

Connecting subwoofers to a 2-channel audio amp.
 

Posts like this do not deserve any response but, in the small
possibility that someone takes him seriously, I will add that there
are several powered subwoofers which
(1)take speaker-level inputs,
(2)have a passive speaker-level crossover,
(3)feed the high-pass output to terminals for the left/right speakers
and,
(4)via a resistive network, pass the LP output to the built-in power
amp and subwoofer driver.

Kal

On Sat, 13 Jan 2007 01:15:54 +1100, "Phil Allison"
wrote:


"Kalman Rubinson = Brainless Pile of Kike **** "


Not exactly. What your friend needs is 1 or 2 subs with a
speaker-level crossover. Then, he can connect the main amp outputs to
the sub(s) and then connect the main L/R speakers to the crossover
outputs on the subs. Thus, the crossovers will divide the frequency
spectrum appropriately.


** No such passive sub x-over * really * exists - you PITA ****wit.

Any specs or web pages that suggest otherwise a total FICTION !!



For this, I prefer powered (built-in amp) subs so that they do not
draw any significant power from the main amp


** Which UTTERLY contradicts your previous para.


APPARENTLY: There is absolutely no upper limit to the * asinine *****
that know nothing poseurs like this cretin will attempt promulgate.

But I am more than happy to stick a giant spanner in the dumb ****'s works.





........ Phil

Connecting subwoofers to a 2-channel audio amp.
 

Kalman Rubinson wrote:

Posts like this do not deserve any response but, in the small
possibility that someone takes him seriously, I will add that there
are several powered subwoofers which
(1)take speaker-level inputs,
(2)have a passive speaker-level crossover,
(3)feed the high-pass output to terminals for the left/right speakers
and,
(4)via a resistive network, pass the LP output to the built-in power
amp and subwoofer driver.

I think you will find that they
1) take speaker-level inputs
2) which are directly connected to terminals for the left/right speakers
3) via a resistive network, combine L+R and feed it to an electronic
LP filter and thence to the built-in power amp and subwoofer driver.

Please feel free to give an example of one that works your way.

--
Eiron.

Connecting subwoofers to a 2-channel audio amp.
 

"Serge Auckland" wrote in message
...
Keith G wrote:


IOW, is a pair of subs a possible complication that might be best *not*
bothered with....??




Should work wonderfully well using one of your 4W SETs............



Well, on my *8W* SET/InFidelios the results are astounding - 'listening' by
leaning my head back against the (drywall partition) wall, the bass from
Bjork's 'Headphones' without the sub rattles my head anyway. With the sub
though, it is not really bearable for long and quite queasy but there is
some 'wuffa wuffa wuffa' roll-off after a seriously deep bit!

Interestingly, the bass with the sub doesn't actually really sound any
deeper than the speakers on their own, only *feels* it...!!

More, much more, to do yet - mebbe even some recording comparisons....



Seriously, in your room, a single sub should be more than ample.


Sure, I don't think I could stand more than the one!!


As to
phasing, I really don't understand the point of a variable phase control.
0 & 180 switched should be provided to phase up the sub with the mains
(which hopefully will be in phase with each other), but apart from that, I
can't see it's possible to match the phase of the main LF, as it will be
frequency dependant. As you suggest, with two subs, trying to get the
phase right would be a nightmare.


I've twiddled it back and forth and can't say it makes a lot of difference
anyway and it ends up back at 0 deg!



Other controls needed are a crossover frequency selector and a level
control. Ideally, if the main speakers are small (say don't go below 70Hz)
then the extreme bass should be rolled-off to the mains considerably
improving their power handling and lowering distortion.


Not sure I understood that....??

Connecting subwoofers to a 2-channel audio amp.
 

"Keith G" wrote


Well, on my *8W* SET/InFidelios the results are astounding - 'listening'
by leaning my head back against the (drywall partition) wall, the bass
from Bjork's 'Headphones' without the sub rattles my head anyway. With the
sub though, it is not really bearable for long and quite queasy but there
is some 'wuffa wuffa wuffa' roll-off after a seriously deep bit!

Interestingly, the bass with the sub doesn't actually really sound any
deeper than the speakers on their own, only *feels* it...!!

More, much more, to do yet - mebbe even some recording comparisons....


Footnote:

Swim has been subjected to brief snatches of extreme bass on a with/without
sub basis throughout the evening. I have just asked her for a snap answer to
the 'Do I need a sub?' question!

Immediate answer - 'Nope'.....

??

?

Connecting subwoofers to a 2-channel audio amp.
 

"Roy"

Well that's EXACTLY how my Harbeth subs work.


** You have totally failed to take account of the context - ****wit.





........ Phil

Connecting subwoofers to a 2-channel audio amp.
 

"Kalman Rubinson ****ing MORON "



Posts like this do not deserve any response but, in the small
possibility that someone takes him seriously,


** I am ABSOLUTELY RIGHT !!

YOU are know nothing, brain dead audiophool arsehole.



I will add that there
are several powered subwoofers which
(1)take speaker-level inputs,
(2)have a passive speaker-level crossover,


** No they do not.

Ever pulled one apart to see what is ACTUALLY fitted inside??

Their maker's lie.




......... Phil

Connecting subwoofers to a 2-channel audio amp.
 

"Eiron"


I think you will find that they
1) take speaker-level inputs
2) which are directly connected to terminals for the left/right speakers
3) via a resistive network, combine L+R and feed it to an electronic
LP filter and thence to the built-in power amp and subwoofer driver.

Please feel free to give an example of one that works your way.



** Don't ask the STEAMING GREAT IDIOT to do that.

All the useless cretin will do is post links to false and misleading
information.




....... Phil

Connecting subwoofers to a 2-channel audio amp.
 

On Sat, 13 Jan 2007 00:13:08 +0000, Eiron wrote:

Kalman Rubinson wrote:

Posts like this do not deserve any response but, in the small
possibility that someone takes him seriously, I will add that there
are several powered subwoofers which
(1)take speaker-level inputs,
(2)have a passive speaker-level crossover,
(3)feed the high-pass output to terminals for the left/right speakers
and,
(4)via a resistive network, pass the LP output to the built-in power
amp and subwoofer driver.

I think you will find that they
1) take speaker-level inputs
2) which are directly connected to terminals for the left/right speakers
3) via a resistive network, combine L+R and feed it to an electronic
LP filter and thence to the built-in power amp and subwoofer driver.

Please feel free to give an example of one that works your way.

I take your correction for point #3 which is functionally equivalent.
As for point #4, see
http://www.definitivetech.com/specs/...ml#poweredsubs
for an example.

Kal

Connecting subwoofers to a 2-channel audio amp.
 

"Kalman Rubinson Bloody IDIOT "

I take your correction for point #3 which is functionally equivalent.
As for point #4, see
http://www.definitivetech.com/specs/...ml#poweredsubs
for an example.


** An example of what ?

Falsifying specifications ?

Or totally meaningless specifications.





........ Phil

Connecting subwoofers to a 2-channel audio amp.
 

Kalman Rubinson wrote:

On Sat, 13 Jan 2007 00:13:08 +0000, Eiron wrote:


Kalman Rubinson wrote:


Posts like this do not deserve any response but, in the small
possibility that someone takes him seriously, I will add that there
are several powered subwoofers which
(1)take speaker-level inputs,
(2)have a passive speaker-level crossover,
(3)feed the high-pass output to terminals for the left/right speakers
and,
(4)via a resistive network, pass the LP output to the built-in power
amp and subwoofer driver.

I think you will find that they
1) take speaker-level inputs
2) which are directly connected to terminals for the left/right speakers
3) via a resistive network, combine L+R and feed it to an electronic
LP filter and thence to the built-in power amp and subwoofer driver.

Please feel free to give an example of one that works your way.


I take your correction for point #3 which is functionally equivalent.
As for point #4, see
http://www.definitivetech.com/specs/...ml#poweredsubs
for an example.

Thanks for the example. First one I've seen.
That one does feed the speakers via a first order HP crossover,
or in other words, through a capacitor. The turnover frequency varies
according to your speakers, their impedance and Q of any bass resonances
and the tolerance of the capacitor.
A bit of a lottery really.

--
Eiron.

Connecting subwoofers to a 2-channel audio amp.
 

In article , Serge Auckland
wrote:


I really don't understand the point of a variable phase
control. 0 & 180 switched should be provided to phase up the sub with
the mains (which hopefully will be in phase with each other), but apart
from that, I can't see it's possible to match the phase of the main LF,
as it will be frequency dependant. As you suggest, with two subs, trying
to get the phase right would be a nightmare.

I found the variable 'phase' control on the sub I use to be useful. It
allowed me to adjust the response in the region where both the sub and the
main speakers were producing similar output levels. No idea how useful
others would find this, 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

Connecting subwoofers to a 2-channel audio amp.
 

Eiron wrote:


Which model of Harbeth subwoofer do you have?


MS1 (a pair of)

Roy.

Connecting subwoofers to a 2-channel audio amp.
 

"Roy"
Eiron wrote:


Which model of Harbeth subwoofer do you have?


MS1 (a pair of)



** Specifically designed to accompany a particular Harbeth bookshelf
speaker.

Learn to read - ANYTIME - ****WIT.




........ Phil

Connecting subwoofers to a 2-channel audio amp.
 

"Eiron"

Some Kike Idiot posted.

http://www.definitivetech.com/specs/...ml#poweredsubs


Thanks for the example. First one I've seen.


** Chinese sub-woofer " plate amplifiers " are nearly all made like this.

A total scam.



That one does feed the speakers via a first order HP crossover,
or in other words, through a capacitor.


** A very cheap and nasty bi-polar electro of about 250 uF.


The turnover frequency varies
according to your speakers, their impedance and Q of any bass resonances
and the tolerance of the capacitor.


** The x-over frequency is basically non existent with most bookshelf
speakers - whether tuned reflex or sealed.

All bass resonance damping is * completely lost * and little if any of the
desired reduction in cone excursion at sub bass frequencies is supplied by
such a series cap.

A total scam.


A bit of a lottery really.


** Might be OK with a pair of Quad ESL57s.

Nothing else.




....... Phil

Connecting subwoofers to a 2-channel audio amp.
 

Keith G wrote:
"Serge Auckland" wrote in message
...
Keith G wrote:


IOW, is a pair of subs a possible complication that might be best *not*
bothered with....??




Should work wonderfully well using one of your 4W SETs............



Well, on my *8W* SET/InFidelios the results are astounding - 'listening' by
leaning my head back against the (drywall partition) wall, the bass from
Bjork's 'Headphones' without the sub rattles my head anyway. With the sub
though, it is not really bearable for long and quite queasy but there is
some 'wuffa wuffa wuffa' roll-off after a seriously deep bit!

Interestingly, the bass with the sub doesn't actually really sound any
deeper than the speakers on their own, only *feels* it...!!

More, much more, to do yet - mebbe even some recording comparisons....


Seriously, in your room, a single sub should be more than ample.


Sure, I don't think I could stand more than the one!!


As to
phasing, I really don't understand the point of a variable phase control.
0 & 180 switched should be provided to phase up the sub with the mains
(which hopefully will be in phase with each other), but apart from that, I
can't see it's possible to match the phase of the main LF, as it will be
frequency dependant. As you suggest, with two subs, trying to get the
phase right would be a nightmare.


I've twiddled it back and forth and can't say it makes a lot of difference
anyway and it ends up back at 0 deg!


Other controls needed are a crossover frequency selector and a level
control. Ideally, if the main speakers are small (say don't go below 70Hz)
then the extreme bass should be rolled-off to the mains considerably
improving their power handling and lowering distortion.


Not sure I understood that....??


If the main 'speakers are small, they won't reproduce deep bass. Feeding
them with deep bass from the power amp will only serve to stress the
bass unit suspension and heat up the voice coil without actually
producing any sound. It is therefore better to limit the bass drive to
small speakers so that they are only given what they can deal with. It
is actually much better if the bass reduction can be done *before* the
power amplifier so that the PA isn't being asked to generate unusable
volts. This way, the power amp driving the small 'speakers will be able
to generate more volts that the 'speakers *can* handle, and so
effectively produce a higher output.

For my son's Christmas present some years ago, I built him a subwoofer
system consisting of an electronic filter removing bass below a preset
frequency, a mono combiner and filter providing a balanced output to a
single subwoofer. The filter frequencies were selectable as was levels
to the subwoofer. The main 'speakers (small Missions) were connected to
the L&R output of a Quad 303 and were driven from 70Hz upwards. 70Hz
downwards was monoed to a balanced output driving a 100wpc AIWA power
amp in bridge mode into the subwoofer which was a large bass-reflex box
tuned to 20Hz. It was most successful, and saw him through his
University days and afterwards, not always to the pleasure of his
neighbours however....

S.

Connecting subwoofers to a 2-channel audio amp.
 

Phil Allison wrote:
"Roy"
Eiron wrote:

Which model of Harbeth subwoofer do you have?

MS1 (a pair of)



** Specifically designed to accompany a particular Harbeth bookshelf
speaker.

Learn to read - ANYTIME - ****WIT.


But if they work well with others too, then why not?

Halfwit.