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

"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

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

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

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.

"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....??

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

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.

"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....??

"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'.....

??

?