"Wally" wrote in message


Stewart Pinkerton wrote:

Will the presence or otherwise of bass frequencies affect how the
cable transfers the high frequencies?

No. This *has* been tried experimentally, and even with ten amps of
bass frequency current flowing, no artifact above -140dB could be
observed in treble tones.

So, what sort of artifact was there in the treble tones?

Nothing audible. -140 dB corresponds to one part in ten million. Pinkerton's
point is even with measurements with that incredible level of sensitivity,
there are no artifacts to be seen.

Once upon a time, a well-known expert in audio perception (James Johnson,
then of AT&T labs, now of Microsoft) was asked for an unconditional limit to
audibility, and he said -100 dB.

This would be under absolutely ideal listening conditions, including an
unbelievably quiet room.

100 dB is the unconditional limit, for sure.

With the usual real-world messiness, the 100 dB almost always falls to
something like 60 to 80 dB, and can be as poor as 20 dB.

IOW if a spurious response is 20 dB or less down, you'll probably hear it
regardless. In typical studio or listening room conditions, you might hear
something that is 70 dB down. Under the most ideal conditions imaginable,
something 100 dB just might be audible.

Hearting something 140 dB down is really unimaginable, in real-world terms.

I can measure artifacts up to about 120 dB down, and at that point copper is
still a *perfect* conductor of audio signals, as are most common metals -
brass, aluminum, tin, nickel, gold, silver, lead, steel... However, add a
little surface contamination at the contact point, and all bets are off!

Arny Krueger wrote:

"Nick Gorham" wrote in message


Stewart Pinkerton wrote:


On Sat, 13 Dec 2003 17:01:09 -0000, "RJH"
wrote:



Well, thanks for all the opinions. I can't really argue with the
technical knowledge you all have, and I looked at Jim Lesurf's (I
think) page a while back and that seemed to say 'no measurable
difference'. I've given it a go with some old qed 79 strand biwire
stuff I happen to have, and I'm afraid I think it sounds a bit
better, particularly extremes - bass and treble.


Interesting, since it's only around the crossover that biwiring has
even the slightest theoretical advantage.


I can't convince myself that this may (or may not) make a difference,
but one point is that while both wires see the same voltage, the cable
to the treble posts are only carrying the current produced by the
treble part of the signal.


However, since copper wire is highly linear, there are few if any
consequences - nothing audible as long as either cable is itself a competent
piece of work.


Agreed, however if there are any problems with poor or dirty connectors
then maybe this could make a difference.

--
Nick

Arny Krueger wrote:

"Nick Gorham" wrote in message


Stewart Pinkerton wrote:


On Sat, 13 Dec 2003 17:01:09 -0000, "RJH"
wrote:



Well, thanks for all the opinions. I can't really argue with the
technical knowledge you all have, and I looked at Jim Lesurf's (I
think) page a while back and that seemed to say 'no measurable
difference'. I've given it a go with some old qed 79 strand biwire
stuff I happen to have, and I'm afraid I think it sounds a bit
better, particularly extremes - bass and treble.


Interesting, since it's only around the crossover that biwiring has
even the slightest theoretical advantage.


I can't convince myself that this may (or may not) make a difference,
but one point is that while both wires see the same voltage, the cable
to the treble posts are only carrying the current produced by the
treble part of the signal.


However, since copper wire is highly linear, there are few if any
consequences - nothing audible as long as either cable is itself a competent
piece of work.


Agreed, however if there are any problems with poor or dirty connectors
then maybe this could make a difference.

--
Nick

RJH wrote:

"Form@C" wrote in message
news
On Fri, 12 Dec 2003 09:11:18 +0000, RJH wrote:


Hi - I've just bought some speakers, JMLab Chorus 715, marvellous.

Anyway,

something in the setup instructions intrigued me - bi-wiring "reduces or
eliminates any problem caused by the bass drivers feeding any signal

back to

the amplifier. This signal intermodulates and spoils the sound quality

of

the midrange and treble". Er, what?!

I don't bother with biwiring as a rule, but should this cause a rethink?


Some say better, some say no difference, some say worse.
Try it - it's only the cost of a bit of speaker cable! Make decent stands

a

priority though. Personally, I have bi-wired a (heavily modified) old pair

of

Kef Codas & I *think* they sound better. That's enough for me. It may be
just in my mind, but so what?

--
Mick
http://www.nascom.info for Nascom & Gemini information
Also at http://www.mixtel.co.uk where the collection started.
Currently deserting M$ for linux... :-)


Well, thanks for all the opinions. I can't really argue with the technical
knowledge you all have, and I looked at Jim Lesurf's (I think) page a while
back and that seemed to say 'no measureable difference'. I've given it a go
with some old qed 79 strand biwire stuff I happen to have, and I'm afraid I
think it sounds a bit better, particularly extremes - bass and treble. There
could be other variables - the cable itself, or the fact that I cleaned
everything while I was at it. Being gullible isn't too bad if it doesn't
cost anything! You may note that some of Focus-JMLabs' really expensive
speakers (well, £5k) don't have biwire facility. Wonder why?


Well assuming for one moment that biwiring did make a difference, and I
don't think it does myself, then it would only make sense for a two way
speaker. Tri or quad would be needed, and I think I remember that the
bigger JML are like that.

--
Nick

RJH wrote:

"Form@C" wrote in message
news
On Fri, 12 Dec 2003 09:11:18 +0000, RJH wrote:


Hi - I've just bought some speakers, JMLab Chorus 715, marvellous.

Anyway,

something in the setup instructions intrigued me - bi-wiring "reduces or
eliminates any problem caused by the bass drivers feeding any signal

back to

the amplifier. This signal intermodulates and spoils the sound quality

of

the midrange and treble". Er, what?!

I don't bother with biwiring as a rule, but should this cause a rethink?


Some say better, some say no difference, some say worse.
Try it - it's only the cost of a bit of speaker cable! Make decent stands

a

priority though. Personally, I have bi-wired a (heavily modified) old pair

of

Kef Codas & I *think* they sound better. That's enough for me. It may be
just in my mind, but so what?

--
Mick
http://www.nascom.info for Nascom & Gemini information
Also at http://www.mixtel.co.uk where the collection started.
Currently deserting M$ for linux... :-)


Well, thanks for all the opinions. I can't really argue with the technical
knowledge you all have, and I looked at Jim Lesurf's (I think) page a while
back and that seemed to say 'no measureable difference'. I've given it a go
with some old qed 79 strand biwire stuff I happen to have, and I'm afraid I
think it sounds a bit better, particularly extremes - bass and treble. There
could be other variables - the cable itself, or the fact that I cleaned
everything while I was at it. Being gullible isn't too bad if it doesn't
cost anything! You may note that some of Focus-JMLabs' really expensive
speakers (well, £5k) don't have biwire facility. Wonder why?


Well assuming for one moment that biwiring did make a difference, and I
don't think it does myself, then it would only make sense for a two way
speaker. Tri or quad would be needed, and I think I remember that the
bigger JML are like that.

--
Nick

"Nick Gorham" wrote in message

Arny Krueger wrote:

"Nick Gorham" wrote in message


Stewart Pinkerton wrote:


On Sat, 13 Dec 2003 17:01:09 -0000, "RJH"
wrote:



Well, thanks for all the opinions. I can't really argue with the
technical knowledge you all have, and I looked at Jim Lesurf's (I
think) page a while back and that seemed to say 'no measurable
difference'. I've given it a go with some old qed 79 strand biwire
stuff I happen to have, and I'm afraid I think it sounds a bit
better, particularly extremes - bass and treble.

Interesting, since it's only around the crossover that biwiring has
even the slightest theoretical advantage.

I can't convince myself that this may (or may not) make a
difference, but one point is that while both wires see the same
voltage, the cable to the treble posts are only carrying the
current produced by the treble part of the signal.

However, since copper wire is highly linear, there are few if any
consequences - nothing audible as long as either cable is itself a
competent piece of work.


Agreed, however if there are any problems with poor or dirty
connectors then maybe this could make a difference.

Agreed, but since we're talking about avoidable mistakes, more likely would
be an undesirable polarity switch of one of the two cables.

"Nick Gorham" wrote in message

Arny Krueger wrote:

"Nick Gorham" wrote in message


Stewart Pinkerton wrote:


On Sat, 13 Dec 2003 17:01:09 -0000, "RJH"
wrote:



Well, thanks for all the opinions. I can't really argue with the
technical knowledge you all have, and I looked at Jim Lesurf's (I
think) page a while back and that seemed to say 'no measurable
difference'. I've given it a go with some old qed 79 strand biwire
stuff I happen to have, and I'm afraid I think it sounds a bit
better, particularly extremes - bass and treble.

Interesting, since it's only around the crossover that biwiring has
even the slightest theoretical advantage.

I can't convince myself that this may (or may not) make a
difference, but one point is that while both wires see the same
voltage, the cable to the treble posts are only carrying the
current produced by the treble part of the signal.

However, since copper wire is highly linear, there are few if any
consequences - nothing audible as long as either cable is itself a
competent piece of work.


Agreed, however if there are any problems with poor or dirty
connectors then maybe this could make a difference.

Agreed, but since we're talking about avoidable mistakes, more likely would
be an undesirable polarity switch of one of the two cables.

"RJH" wrote

snip

Well, thanks for all the opinions. I can't really argue with the technical
knowledge you all have, and I looked at Jim Lesurf's (I think) page a
while
back and that seemed to say 'no measureable difference'. I've given it a
go
with some old qed 79 strand biwire stuff I happen to have, and I'm afraid
I
think it sounds a bit better, particularly extremes - bass and treble.
There
could be other variables - the cable itself, or the fact that I cleaned
everything while I was at it. Being gullible isn't too bad if it doesn't
cost anything!



Don't feel too bad about this - Samuel Johnson (1709-84) has already covered
the subject of bi-wiring with the following:

"All argument is against it; but all belief is for it".........

"RJH" wrote

snip

Well, thanks for all the opinions. I can't really argue with the technical
knowledge you all have, and I looked at Jim Lesurf's (I think) page a
while
back and that seemed to say 'no measureable difference'. I've given it a
go
with some old qed 79 strand biwire stuff I happen to have, and I'm afraid
I
think it sounds a bit better, particularly extremes - bass and treble.
There
could be other variables - the cable itself, or the fact that I cleaned
everything while I was at it. Being gullible isn't too bad if it doesn't
cost anything!



Don't feel too bad about this - Samuel Johnson (1709-84) has already covered
the subject of bi-wiring with the following:

"All argument is against it; but all belief is for it".........

On Tue, 16 Dec 2003 14:53:16 +0000, Nick Gorham
wrote:

Arny Krueger wrote:

"Nick Gorham" wrote in message


I can't convince myself that this may (or may not) make a difference,
but one point is that while both wires see the same voltage, the cable
to the treble posts are only carrying the current produced by the
treble part of the signal.

However, since copper wire is highly linear, there are few if any
consequences - nothing audible as long as either cable is itself a competent
piece of work.

Agreed, however if there are any problems with poor or dirty connectors
then maybe this could make a difference.

Yes indeed - and there are twice as many connections to a bi-wired
speaker...........................
--

Stewart Pinkerton | Music is Art - Audio is Engineering