bi-wire config question
 

Glenn Richards wrote:
APR wrote:

All you are doing with bi-wiring is placing the terminal that joins
the the LF and HF driver circuit inputs at the amp terminals instead
of the speaker terminals. If the speaker wire is so inadequate that
you are able to measure any significant changes in HF linearity due
to the effect of speaker wire resistance then the wire run is too
long or the wire is too light.

Ok, for those people that still don't "get it", here's an experiment
that will demonstrate visually what's going on:

Take a 12V DC power supply (one of those bench PSUs capable of supplying
several amps will suffice) and a 12V 1W bulb (any type will do, it's
easier to perform the experiment using a MES bulb and batten holder with
screw terminals though).

Connect the bulb to the power supply using 5 metres of 13-strand zip
wire and power up. Observe the brightness of the bulb.

Now take a second bulb and holder, and attach a few inches of the same
wire to the second holder. Connect the second bulb in parallel with the
first so that it is "chained" from the first bulb, ie you've got 5m of
cable from PSU to first bulb, then a few inches from the first bulb to
the second bulb. Make this connection with the power turned on.

As you connect the second bulb, you'll see the first bulb's brightness
decrease. This is caused by a voltage drop in the cable. Disconnect the
second bulb and the brightness of the first will increase again.

Now replace the short piece of wire on the second bulb with another 5
metre length, and connect the two bulbs in parallel by attaching two
sets of wire to the power supply. This time when you connect the second
bulb the first one won't dim, and the second will light up at full
brightness.

This is exactly what is happening with your speaker cables. The cable
run acts like a series resistor, and the load (in this case the driver
voice coil) causes a voltage drop across that series resistor. By
bi-wiring you are avoiding the load from the LF driver causing a voltage
drop to the HF driver. (Again this is a greatly simplified description
of what's going on.)

No it isn't! Your experiment is being done with dc. Repeat the
experiment with 50Hz to one bulb and 10kHz to the second bulb, both
bulbs being fed through a single amplifier and fed through a simple
capacitor or inductor "crossover". You will now see that the bulbs don't
change their brightness.

S

bi-wire config question
 

In article , Howard Haigh
wrote:

"Jim Lesurf" wrote in message
...

[snip]

These show that bi wiring can change the frequency response -
but by only a small amount even when using cables of exceptionally
high series resistance. Hence changes in measured behaviour are
possible. But are they audible in any sensible arrangement?... My
reaction tends to be that if I wanted a change in frequency response
of a few tenths of a dB I'd move my head slightly whilst listening.
:-)


Ah yes - the issue of listening position! Something I've noticed is that
when listening to music if I happen to tilt my head so that I'm either
looking upwards or downwards then there is a discernable change in the
sound - I hear more or less treble. I suspect that the actual shape of
my ears influences how well certain frequencies are heard. So (assuming
that I'm not the only one that this affects) unless we're going to
restrain our heads in some sort of clamp then any comparitive test of
speaker connectivity is more likely than not going to have to deal with
'is my head in exactly the right position to make it a fair trial'


This issue can be tackled. However it tends to require some mix of:

1) The listener(s) trying to put their head in the same position(s) as best
they can when comparing. Thus trying to reduce the effect of head movements.

2) *repeated* listening to the 'different arrangements' being compared, in
'randomised' order with the listener not being told which one is being used
at any time, so only having the sounds to go on. Then doing a statistical
analysis of the results.

Protocols//methods like the above can help to 'randomise' the effects of
differences in head location, changes in hearing physiology during the
tests, etc.

The key point here is that experimental physical scientists have for a
long time devised and used methods to 'randomise' uncorrelated effects
and then use test protocols which can be analysed to show the systematic
effect of the 'target' properties. The snag is that people have to
understand and use these methods, which can be time consuming and require
care and atention.

Alas, many of the reports are along the lines of, "I tried arrangement A,
then I tried arrangement B and they sounded different to me. Thus they do
sound different." For reasons like those above, such reports can be simply
wrong. They may also easily assign as the 'reason' for an 'audible
difference' to entirely the wrong cause. Thus as 'evidence' such reports
are of little use.


and indeed if moving one's head slightly can affect the sound heard then
is there any point in worrying about minor changes that might be
imparted via the speaker cable arrangement?

Indeed. :-) Personally, I stopped trying to chase 'differences' that were
this small some years ago - particularly when the 'evidence' seemed to
consist of unreliable reports of poorly-conducted 'tests'. Simpler to use
the time on enjoying the music. Take such reports in magazine reviews, etc
with a pinch of salt. :-)

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

bi-wire config question
 

In article , Glenn
Richards wrote:
Serge Auckland wrote:

You've obviously convinced yourself that it makes a difference. I've
never managed to hear any myself, and when I do the sums, I'm not a
bit surprised. By the way, if you are indeed sure it does make a
difference, have you tried to analyse why and how? What mechanism can
be acting to make the sound better (or even different)?

[snip]

Once you take the bridging straps off however, something else is
occurring. And what happens makes an audible difference. Too tired to do
the maths atm, but I'm sure a few ASCII art diagrams will help.

Actually, if people visit the webpages I've been mentioning they can see
the relevant diagrams displayed as gif images on the pages. Also the
relevant equiations modelling the arrangements, and the results for a
simple example. :-)

[snip]


Treat the run of cable between the amp and speaker as if it were a
resistor and it makes it easier to understand what's happening. And
remember that the LF driver can take a hefty current when you're trying
to move a lot of air - and that current is effectively being drawn
through a series resistor (ie the run of speaker cable). By bi-wiring,
you're no longer drawing that high current required by the LF driver
through the same series resistor as the HF driver.

That is correct. but you are drawing through another series resistor.

If the bi-wire cables are similar to the one used for conventional
wiring, then the HF signal will pass through the same series resistance
as before, and endure a similar Ohmic drop.

The result - much more linearity from the HF driver, as it's no longer
suffering from current drain via a series resistor when the LF driver
draws current.

That does not seem to follow from the above, and seem either incorrect or
confused. You gave changed one resistor (linear device) with another.
None of the above gives any reason for the result to be "much more linear".

If you change from using a common cable of series resistance, R, to one of
R feeding the HF driver, it will see a cable resistance of R in both cases.

The resistance of the cable will essentially be a linear element in both
cases.

Thus there is no need to assume any significant result in terms of "much
more linearity from the HF driver".

Therefore no current sag to the HF driver, resulting in a cleaner and
more dynamic HF response.

Not clear what 'current sag' you are assuming, nor why...

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

bi-wire config question
 

In article , Glenn Richards
wrote:
Eiron wrote:

Glenn said recently: "(HF needs less current so a thinner cable will
suffice)." Which shows that there is no point in discussing technical
stuff with him, unless it is to give the rest of us a laugh.

It's called "speaking in layman's terms". Some people aren't technically
minded, and don't really care about the how and the why, just the what.

But since you're being pedantic, let's put it another way. A loudspeaker
voice coil is basically a linear motor. The LF driver is going to draw
more current than the HF driver


Experience on usenet is that being pedantic can be unwise as someone
else will then nit-pick the 'pedantry'...

In this case I can point out that the LF and HF currents will vary
according to the signal patterns, as well as depending on the details
of the speaker units. Hence the above "is going to" would be better
expressed as "often tends to..."


- which should be blindingly obvious as it has to move in and out much
more (a throw of anything up to an inch or so). The HF driver only moves
by a few microns, as the frequencies it is reproducing are far higher.


Well, the powers/currents are required to *accellerate* the drivers.
Hence simply quoting the displacements is misleading in the above context.

The coil current (in the magnetic field) produces a force which then
accellerates the driver. The important point here is that the HF driver
tends to have a smaller mass than an LF driver, so lower forces are
required for a given accelleration.

The reduction in amplitude of movement simply comes from the higher
frequency, meaning that the acceleration in a given direction is 'reversed'
after a shorter time period.

Therefore the HF driver is going to draw far less current than the LF
driver - and therefore is less likely to be affected by a slightly
higher series resistance (eg a thinner cable) than the LF driver.

Alas, the above is misleading. The effect of high cable resistance is in
terms of the *impedance* interactions, altering the frequency response.
This will include the presence of any crossover/correction networks.

The HF and LF speakers may well also have different masses, coil details,
loss resistances, etc, etc. Hence we can't use the above to draw the
conclusion drawn above.


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

bi-wire config question
 

In article , Glenn Richards
wrote:
APR wrote:

All you are doing with bi-wiring is placing the terminal that joins
the the LF and HF driver circuit inputs at the amp terminals instead
of the speaker terminals. If the speaker wire is so inadequate that
you are able to measure any significant changes in HF linearity due to
the effect of speaker wire resistance then the wire run is too long
or the wire is too light.

Ok, for those people that still don't "get it", here's an experiment
that will demonstrate visually what's going on:

Take a 12V DC power supply (one of those bench PSUs capable of supplying
several amps will suffice) and a 12V 1W bulb (any type will do, it's
easier to perform the experiment using a MES bulb and batten holder with
screw terminals though).

[snip details]

This is exactly what is happening with your speaker cables. The cable
run acts like a series resistor, and the load (in this case the driver
voice coil) causes a voltage drop across that series resistor.

The point to bear in mind, though, is that the cable resistance for any
sensible speaker cables should be tiny. Hence any effect should
be negligably small. If it isn't simply use thicker/shorter loudspeaker
cables. The following URL may help assess this.

http://www.st-and.demon.co.uk/AudioM.../lscables.html

For cable lengths of a few metres, the cables which cost the order of
50p per foot are likely to be fine, but the choice is up to you. :-)


Bybi-wiring you are avoiding the load from the LF driver causing a
voltage drop to the HF driver. (Again this is a greatly simplified
description of what's going on.)

To assess this, have a look at the other webpages I have been mentioning.
If you look at the simple example it should be clear that this implies that
any such effect in practice should tend to be so small as to be either
inaudible or smaller than moving your head slightly. If it isn't then
simply using a lower resistance cable should deal with the issue - unless
of course you *want* to alter the frequency response by the deliberate
introduction of 'high' cable resistance.

However if you do want this, then it would be easier and more controllable
to use a single cable, but feed the speaker units via some series resistors
at the speaker end of the cable. This method is familiar to speaker
designers. It is called "modifying the crossover/correction networks". :-)

You may find that a couple of low-value resistors are cheaper and more
convenient that more runs of cable. You can also change their values easily
if you want to fiddle about with the frequency response of your loudspeaker
system.

I've specified 13-strand zip wire in the experiment above as it makes
the results more obvious, but the effect will still stand with thicker
cable, it'll just be harder to see. And eventually you'll get to a
thickness of cable that will have a low enough series resistance that
the effect will no longer occur - but in the case of speakers that cable
will either be so expensive or so unwieldy that it makes more sense to
use two thinner runs of cable.

FWIW I tend to prefer the Maplin cables as they give low series resistance
for just a few quid per cable. The above URL uses them for example, so
people can decide for themselves what might suit for the lengths they need.

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

bi-wire config question
 

Serge Auckland wrote:

No it isn't! Your experiment is being done with dc. Repeat the
experiment with 50Hz to one bulb and 10kHz to the second bulb, both
bulbs being fed through a single amplifier and fed through a simple
capacitor or inductor "crossover". You will now see that the bulbs
don't change their brightness.

Makes no difference, AC or DC. Series resistance is still the same,
regardless of line frequency. That experiment was to illustrate a
concept, not specifics. The principle is exactly the same.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

Don Pearce wrote:

Glenn, as I said in another post, please stop this. You have a
minuscule technical knowledge which ends far short of an ability to
understand and apply Ohm's law, but you persist in airing your
howlers. I know we are all amused when we have nothing better to do,
but you really are doing yourself no favours.

As opposed to you, who has already proved in a previous post that you
have no idea how an earth loop works, interpreted "two signals" to mean
combining a stereo signal onto a single core and couldn't understand the
correlation between "unwanted signal" and "noise" (hint - "noise" is any
"unwanted signal") etc etc.

You've proved your own ineptitude, now please stop foisting your
inadequacies onto me. This is Usenet, not work, and I don't get paid for
doing this. Therefore I'm not going to write a highly detailed analysis
of why bi-wiring does make a difference (and I can assure you it does)
which you've already demonstrated that you won't understand anyway.

Now please go back to your £39.99 micro system purchased from Currys
with speakers linked up with bell wire, and stop pretending you know
anything about hi-fi.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

On Sun, 18 Jun 2006 11:13:57 +0100, Glenn Richards
wrote:

Don Pearce wrote:

Glenn, as I said in another post, please stop this. You have a
minuscule technical knowledge which ends far short of an ability to
understand and apply Ohm's law, but you persist in airing your
howlers. I know we are all amused when we have nothing better to do,
but you really are doing yourself no favours.

As opposed to you, who has already proved in a previous post that you
have no idea how an earth loop works, interpreted "two signals" to mean
combining a stereo signal onto a single core and couldn't understand the
correlation between "unwanted signal" and "noise" (hint - "noise" is any
"unwanted signal") etc etc.

Glenn, I said no such thing - as that is complete nonsense. If that is
what you interpreted from what I said, it only illustrates your lack
of understanding.

You've proved your own ineptitude, now please stop foisting your
inadequacies onto me. This is Usenet, not work, and I don't get paid for
doing this. Therefore I'm not going to write a highly detailed analysis
of why bi-wiring does make a difference (and I can assure you it does)
which you've already demonstrated that you won't understand anyway.

No, there is actually another reason why you won't do this. I assure
you that the rest of us know what it is.

Now please go back to your £39.99 micro system purchased from Currys
with speakers linked up with bell wire, and stop pretending you know
anything about hi-fi.

If that pleases you.

d

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

bi-wire config question
 

On Sun, 18 Jun 2006 11:13:57 +0100, Glenn Richards
wrote:

Don Pearce wrote:

Glenn, as I said in another post, please stop this. You have a
minuscule technical knowledge which ends far short of an ability to
understand and apply Ohm's law, but you persist in airing your
howlers. I know we are all amused when we have nothing better to do,
but you really are doing yourself no favours.

As opposed to you, who has already proved in a previous post that you
have no idea how an earth loop works, interpreted "two signals" to mean
combining a stereo signal onto a single core and couldn't understand the
correlation between "unwanted signal" and "noise" (hint - "noise" is any
"unwanted signal") etc etc.

You've proved your own ineptitude, now please stop foisting your
inadequacies onto me. This is Usenet, not work, and I don't get paid for
doing this. Therefore I'm not going to write a highly detailed analysis
of why bi-wiring does make a difference (and I can assure you it does)
which you've already demonstrated that you won't understand anyway.

Now please go back to your £39.99 micro system purchased from Currys
with speakers linked up with bell wire, and stop pretending you know
anything about hi-fi.

OK - you snipped the substance, as you had no way of dealing with it.
So I will repeat it again:

First lets assume that your experiment is applicable.
Now complete it. Use you second case - with the two wires
run separately right back to the source ( for maximum brightness). Now
take your short piece of wire and join the two bulbs together. If
biwiring made a difference, there should be a change in brightness as
you do this. There is no change. All you have shown is that it is
usually better to have thicker wire.

The second point is that the tweeter and woofer are not in parallel.
Does that surprise you? This because we are dealing with signals in
defined frequency bands, and we have a crossover, which presents a
high impedance to the cable in the stopband of each driver. This means
that low frequency signals - no matter how big - do not suck voltage
away from the tweeter. In fact the tweeter doesn't even know there is
a woofer there. There are of course electrical devices that have the
effect you describe; they are called modulators and rely on controlled
non-linearity to achieve a multiplying function. If you can show that
cables act as modulators, you will have saved the broadcasting
industry a fortune overnight and your fame will be assured.

Now, answer both of those - if you are able. (breath not being held, I
promise).

d

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

bi-wire config question
 

Don Pearce wrote:

As opposed to you, who has already proved in a previous post that
you have no idea how an earth loop works, interpreted "two signals"
to mean combining a stereo signal onto a single core and couldn't
understand the correlation between "unwanted signal" and "noise"
(hint - "noise" is any "unwanted signal") etc etc.
Glenn, I said no such thing - as that is complete nonsense. If that
is what you interpreted from what I said, it only illustrates your
lack of understanding.

No, that was exactly what you said. You were harping on about "why would
you send two signals down one cable", completely missing the point that
noise is a signal, just one that isn't wanted.

It isn't me that is suffering from a lack of understanding here. I
suggest you go and take a look in the mirror.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

On Sun, 18 Jun 2006 12:40:17 +0100, Glenn Richards
wrote:

Don Pearce wrote:

As opposed to you, who has already proved in a previous post that
you have no idea how an earth loop works, interpreted "two signals"
to mean combining a stereo signal onto a single core and couldn't
understand the correlation between "unwanted signal" and "noise"
(hint - "noise" is any "unwanted signal") etc etc.
Glenn, I said no such thing - as that is complete nonsense. If that
is what you interpreted from what I said, it only illustrates your
lack of understanding.

No, that was exactly what you said. You were harping on about "why would
you send two signals down one cable", completely missing the point that
noise is a signal, just one that isn't wanted.

No, Glenn. What I said repeatedly was that what you needed for a
ground loop was one (minimum, two for stereo, obviously) signal
connection, and *two* ground connections. Those two *ground*
connections are what make a *ground* *loop*. See where the term comes
from now? So kindly don't misquote me. And just so that we are clear -
noise doesn't figure in ground loops, it is hum we are talking about.

It isn't me that is suffering from a lack of understanding here. I
suggest you go and take a look in the mirror.

So funny!

d

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

bi-wire config question
 

Don Pearce wrote:

OK - you snipped the substance, as you had no way of dealing with it.

I think the phrase "couldn't be bothered" springs to mind. But since you
insist...

So I will repeat it again:

yawn

First lets assume that your experiment is applicable. Now complete
it. Use you second case - with the two wires run separately right
back to the source ( for maximum brightness). Now take your short
piece of wire and join the two bulbs together. If biwiring made a
difference, there should be a change in brightness as you do this.
There is no change. All you have shown is that it is usually better
to have thicker wire.

My experiment was a very simple one, designed to demonstrate the effect
of a long run of cable acting like a series resistor. By strapping the
bulbs together when "bi-wired", you're then achieving "C = R / 2", where
C is the series resistance of the cable(s) between the bonding strap and
the amplifier (or power source in this case), and R is the series
resistance of each individual length of cable. Of course this assumes
that both runs of cable are identical.

Now, this experiment uses DC, so only demonstrates resistance. A DC
signal is not affected by inductance (or indeed capacitance between the
cores - series capacitance will block DC but parallel won't). So it
serves only to demonstrate one of several mechanisms in play that means
bi-wiring will give an improvement.

Go back and read my earlier posting where I stated that eventually
you'll reach a thickness of cable where the series resistance becomes so
low that this effect no longer occurs. But a cable this thick will
either be very unwieldy or (comparatively) very expensive, therefore
it's more convenient (or cost effective, as the case may be) to use two
runs of thinner/cheaper cable.

The second point is that the tweeter and woofer are not in parallel.
Does that surprise you? This because we are dealing with signals in
defined frequency bands, and we have a crossover, which presents a
high impedance to the cable in the stopband of each driver. [snip]

Yes, except - there's an equivalent series resistor in the feed to the
"high impedance load". So a voltage drop across the LF *will* affect the HF.

By bi-wiring, you split the signal before this "series resistor",
therefore a voltage drop across the LF cable won't affect the HF.

Right, enough time wasted on this for now. Let's see if your limited
understanding can make sense of the above...

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

Don Pearce wrote:

And just so that we are clear - noise doesn't figure in ground loops,
it is hum we are talking about.

Hum *is* a form of noise. It's an unwanted signal - and noise is any
unwanted signal.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

On Sun, 18 Jun 2006 12:55:14 +0100, Glenn Richards
wrote:

Don Pearce wrote:

OK - you snipped the substance, as you had no way of dealing with it.

I think the phrase "couldn't be bothered" springs to mind. But since you
insist...

So I will repeat it again:

yawn

First lets assume that your experiment is applicable. Now complete
it. Use you second case - with the two wires run separately right
back to the source ( for maximum brightness). Now take your short
piece of wire and join the two bulbs together. If biwiring made a
difference, there should be a change in brightness as you do this.
There is no change. All you have shown is that it is usually better
to have thicker wire.

My experiment was a very simple one, designed to demonstrate the effect
of a long run of cable acting like a series resistor.

Really, is that all it was? Then why did you claim it illustrated the
beneficial effects of biwiring?

By strapping the
bulbs together when "bi-wired", you're then achieving "C = R / 2", where
C is the series resistance of the cable(s) between the bonding strap and
the amplifier (or power source in this case), and R is the series
resistance of each individual length of cable. Of course this assumes
that both runs of cable are identical.

C=R/2 whether they are strapped together or not. Do you really not see
this? (incidentally, please don't use C for a resistance, it is used
for capacitance).

Now, this experiment uses DC, so only demonstrates resistance. A DC
signal is not affected by inductance (or indeed capacitance between the
cores - series capacitance will block DC but parallel won't). So it
serves only to demonstrate one of several mechanisms in play that means
bi-wiring will give an improvement.

But it clearly shows that biwiring (ie not strapping together at the
bulb end) has no effect. What does have an effect is using a
sufficiently thick cable. If you are going to use a thought experiment
- even as poor a one as this - to prove a point, at least draw the
correct conclusion.

Go back and read my earlier posting where I stated that eventually
you'll reach a thickness of cable where the series resistance becomes so
low that this effect no longer occurs. But a cable this thick will
either be very unwieldy or (comparatively) very expensive, therefore
it's more convenient (or cost effective, as the case may be) to use two
runs of thinner/cheaper cable.

Fine, but the effect is the reverse of what you claim. If you have a
cable so thin that it is harming the sound, then you don't improve it
by biwiring - the same cable resistance is still feeding each driver,
so the loss is the same. What you need to do is parallel the cables so
they are both connected together at both ends. This will have a good
effect because you have now halved the resistance of the cable feeding
each unit.

The second point is that the tweeter and woofer are not in parallel.
Does that surprise you? This because we are dealing with signals in
defined frequency bands, and we have a crossover, which presents a
high impedance to the cable in the stopband of each driver. [snip]

Yes, except - there's an equivalent series resistor in the feed to the
"high impedance load". So a voltage drop across the LF *will* affect the HF.


No it won't. Go read some theory on diplexing.

By bi-wiring, you split the signal before this "series resistor",
therefore a voltage drop across the LF cable won't affect the HF.

Right, enough time wasted on this for now. Let's see if your limited
understanding can make sense of the above...

Glenn, you are living in a muddle. Please go and study.

d

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

bi-wire config question
 

On Sun, 18 Jun 2006 13:03:12 +0100, Glenn Richards
wrote:

Don Pearce wrote:

And just so that we are clear - noise doesn't figure in ground loops,
it is hum we are talking about.

Hum *is* a form of noise. It's an unwanted signal - and noise is any
unwanted signal.

We have three unwanteds in audio:

Hum - induced from the mains
Noise - internally generated random fluctuations
Distortion - signal-related products of nonlinear distortion

Go and learn the difference between them. Then find out why you have
to treat each differently, how they have different causes and of
course different remedies.

And of course none of these is signal, which is defined as the wanted
stuff.

d

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

bi-wire config question
 

In article , Glenn
Richards wrote:
Serge Auckland wrote:

No it isn't! Your experiment is being done with dc. Repeat the
experiment with 50Hz to one bulb and 10kHz to the second bulb, both
bulbs being fed through a single amplifier and fed through a simple
capacitor or inductor "crossover". You will now see that the bulbs
don't change their brightness.

Makes no difference, AC or DC.

Do the experiment Serge described and you will find that the results show
he is correct in what he says. Then as Don has suggested, investigate
diplexing.

Bear in mind that what he describes is the kind of technique routinely
employed and studied by electronic engineers. Indeed, I'd suspect that
more than one undergrad lab may have what Serge describes as an
experiment to show this to students. It is the basis of frequency
division multiplexing in transmission line systems. :-)


Series resistance is still the same, regardless of line frequency.


Actually, not necessarily so. It is quite possible for a cable to
have a resistance that varies with frequency. :-) However even if we
ignore this, what Serge says is correct.


That experiment was to illustrate a concept, not specifics. The
principle is exactly the same.

Only for the specific case you gave. The snag is that loudspeakers aren't
simply resistors.

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

bi-wire config question
 

In article , Don Pearce
wrote:
On Sun, 18 Jun 2006 12:55:14 +0100, Glenn Richards
wrote:



The second point is that the tweeter and woofer are not in parallel.
Does that surprise you? This because we are dealing with signals in
defined frequency bands, and we have a crossover, which presents a
high impedance to the cable in the stopband of each driver. [snip]

Yes, except - there's an equivalent series resistor in the feed to the
"high impedance load". So a voltage drop across the LF *will* affect
the HF.


No it won't. Go read some theory on diplexing.

There may be some effect if the 'out of band' impedances are not suitably
high. However provided the cables and signal source have a low impedance,
etc, they are likely to be irrelevant in practice as they would be too
small to have audible significance.

As usual, it is always possible for someone to assemble a system with
extraordinarily inappropriate properties, but this seems unlikely to be an
issue with sensible cabling, etc, in a domestic audio system.

By bi-wiring, you split the signal before this "series resistor",
therefore a voltage drop across the LF cable won't affect the HF.

I think Don is trying to explain that this will also be the case with
conventional wiring given sensible cables, etc. With a non-zero speaker
resistance and conventional wiring the LF signals will alter the
speaker-end voltages slightly *at LF frequencies* - which the HF speaker is
supposed not to be reproducing, and for which the HF unit and network may
have a high impedance. Linear superposition is your friend here... ;-

I also think that both Don and Serge are pointing out that your approach is
too simplistic, and hence inappropriate and misleading.

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

bi-wire config question
 

On Sun, 18 Jun 2006 12:55:14 +0100, Glenn Richards
wrote:

OK - you snipped the substance, as you had no way of dealing with it.

I think the phrase "couldn't be bothered" springs to mind. But since you
insist...

OK Glenn, maybe you can't be bothered (yeah, right) but I can. I've
done the work for you and simulated the two effects - biwire, or
parallel wire, joined at the far end - in PSpice. The results
vindicate my position completely.

Of course, Spice could be totally invalid along with a couple of
hundred years of theory, I suppose...

Anyway read and weep:

http://81.174.169.10

d

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

bi-wire config question
 

Don Pearce wrote:

OK Glenn, maybe you can't be bothered (yeah, right) but I can. I've
done the work for you and simulated the two effects - biwire, or
parallel wire, joined at the far end - in PSpice. The results
vindicate my position completely.

No they don't.

You've only placed a "lossy" cable on one leg of the speaker cable. So
you've got effectively a 5 metre run of cable from the positive speaker
output, then a short (as close to zero ohms as possible) run back to the
ground point on the amplifier.

Also, most crossovers I've seen often only have a series inductor (for
LF) or series capacitor (for HF), and don't bother strapping L or C
across the load. Admittedly some do, but I just took the plate off the
back of one of my Mission 760iSE speakers, there's a single inductor in
series with the LF driver and a single cap in series with the HF driver.
Clearly a case of KISS (Keep It Simple, Stupid).

Of course, Spice could be totally invalid along with a couple of
hundred years of theory, I suppose...

So how do you explain the fact that when the speakers are bi-wired they
sound better (clearer and sharper treble, more detail etc)? And when
single-wired they sound muddy by comparison?

Hint: the standard uk.rec.audio cop-out of "it's all in your mind" is
not a valid response. Of course it's all "in your mind", your ear only
gathers sound and turns it into electrical signals. It's your mind (or
more technically your brain) that interprets those electrical signals as
noises, whether pleasant or unpleasant. Just in case you feel like
getting pedantic.

Remember that computers do what you tell them to do, not what you want
them to do. So if your model isn't tying up with the observed effects
then your model is obviously wrong.

I'll give you a B+ for effort, E for accuracy. Your computer model does
not match the observed effects. Now, take the effort you're about to
expend on trying to prove me wrong and channel it into finding out why
the observable and repeatable effects occur.

Head teacher's comment: Plenty of enthusiasm, needs to channel self
better. D-.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

On Sun, 18 Jun 2006 14:45:02 +0100, Glenn Richards
wrote:

Don Pearce wrote:

OK Glenn, maybe you can't be bothered (yeah, right) but I can. I've
done the work for you and simulated the two effects - biwire, or
parallel wire, joined at the far end - in PSpice. The results
vindicate my position completely.

No they don't.

You've only placed a "lossy" cable on one leg of the speaker cable. So
you've got effectively a 5 metre run of cable from the positive speaker
output, then a short (as close to zero ohms as possible) run back to the
ground point on the amplifier.

Also, most crossovers I've seen often only have a series inductor (for
LF) or series capacitor (for HF), and don't bother strapping L or C
across the load. Admittedly some do, but I just took the plate off the
back of one of my Mission 760iSE speakers, there's a single inductor in
series with the LF driver and a single cap in series with the HF driver.
Clearly a case of KISS (Keep It Simple, Stupid).

Of course, Spice could be totally invalid along with a couple of
hundred years of theory, I suppose...

So how do you explain the fact that when the speakers are bi-wired they
sound better (clearer and sharper treble, more detail etc)? And when
single-wired they sound muddy by comparison?

Hint: the standard uk.rec.audio cop-out of "it's all in your mind" is
not a valid response. Of course it's all "in your mind", your ear only
gathers sound and turns it into electrical signals. It's your mind (or
more technically your brain) that interprets those electrical signals as
noises, whether pleasant or unpleasant. Just in case you feel like
getting pedantic.

Remember that computers do what you tell them to do, not what you want
them to do. So if your model isn't tying up with the observed effects
then your model is obviously wrong.

I'll give you a B+ for effort, E for accuracy. Your computer model does
not match the observed effects. Now, take the effort you're about to
expend on trying to prove me wrong and channel it into finding out why
the observable and repeatable effects occur.

Head teacher's comment: Plenty of enthusiasm, needs to channel self
better. D-.

Good grief - there really is no end to it.

OK, I've done all I can - anybody else feel like trying?

d

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

bi-wire config question
 

In article , Don Pearce
writes
On Sun, 18 Jun 2006 14:45:02 +0100, Glenn Richards
wrote:

Don Pearce wrote:

OK Glenn, maybe you can't be bothered (yeah, right) but I can. I've
done the work for you and simulated the two effects - biwire, or
parallel wire, joined at the far end - in PSpice. The results
vindicate my position completely.

No they don't.

You've only placed a "lossy" cable on one leg of the speaker cable. So
you've got effectively a 5 metre run of cable from the positive speaker
output, then a short (as close to zero ohms as possible) run back to the
ground point on the amplifier.

Also, most crossovers I've seen often only have a series inductor (for
LF) or series capacitor (for HF), and don't bother strapping L or C
across the load. Admittedly some do, but I just took the plate off the
back of one of my Mission 760iSE speakers, there's a single inductor in
series with the LF driver and a single cap in series with the HF driver.
Clearly a case of KISS (Keep It Simple, Stupid).

Of course, Spice could be totally invalid along with a couple of
hundred years of theory, I suppose...

So how do you explain the fact that when the speakers are bi-wired they
sound better (clearer and sharper treble, more detail etc)? And when
single-wired they sound muddy by comparison?

Hint: the standard uk.rec.audio cop-out of "it's all in your mind" is
not a valid response. Of course it's all "in your mind", your ear only
gathers sound and turns it into electrical signals. It's your mind (or
more technically your brain) that interprets those electrical signals as
noises, whether pleasant or unpleasant. Just in case you feel like
getting pedantic.

Remember that computers do what you tell them to do, not what you want
them to do. So if your model isn't tying up with the observed effects
then your model is obviously wrong.

I'll give you a B+ for effort, E for accuracy. Your computer model does
not match the observed effects. Now, take the effort you're about to
expend on trying to prove me wrong and channel it into finding out why
the observable and repeatable effects occur.

Head teacher's comment: Plenty of enthusiasm, needs to channel self
better. D-.

Good grief - there really is no end to it.

OK, I've done all I can - anybody else feel like trying?

d



'ere guv, how can I bi- or tri wire me ESL63's cos if the squirrelsounds is
right.. I want some of what he's on:))
--
Tony Sayer

bi-wire config question
 

FWIW I tend to prefer the Maplin cables as they give low series resistance
for just a few quid per cable. The above URL uses them for example, so
people can decide for themselves what might suit for the lengths they need.

Slainte,




Maplin guv?, pon me life their pricy..

Someone left some cables from the 400 kV re-wire their doing round this way
and the insulators..you've never seen anything like 'em.

Missus has said either the Pylons go or I do.. so she's packin 'er bags;)))
Jim


--
Tony Sayer

bi-wire config question
 

On Sun, 18 Jun 2006 15:57:05 +0100, tony sayer
wrote:

'ere guv, how can I bi- or tri wire me ESL63's cos if the squirrelsounds is
right.. I want some of what he's on:))
--
Tony Sayer

Troll juice, maybe?

d

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

bi-wire config question
 

On Sun, 18 Jun 2006 16:00:00 +0100, tony sayer
wrote:

FWIW I tend to prefer the Maplin cables as they give low series resistance
for just a few quid per cable. The above URL uses them for example, so
people can decide for themselves what might suit for the lengths they need.

Slainte,




Maplin guv?, pon me life their pricy..

Someone left some cables from the 400 kV re-wire their doing round this way
and the insulators..you've never seen anything like 'em.

Missus has said either the Pylons go or I do.. so she's packin 'er bags;)))
Jim


Do what I do - say to the bloke "I'll give you two quid for what's
left on that roll". Anything less than half a roll, and they will
generally go for it rather than be bothered measuring off what's left.

d

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

bi-wire config question
 

On Sun, 18 Jun 2006 13:36:03 +0100, Jim Lesurf
wrote:

In article , Glenn
Richards wrote:
Serge Auckland wrote:

No it isn't! Your experiment is being done with dc. Repeat the
experiment with 50Hz to one bulb and 10kHz to the second bulb, both
bulbs being fed through a single amplifier and fed through a simple
capacitor or inductor "crossover". You will now see that the bulbs
don't change their brightness.

Makes no difference, AC or DC.

Do the experiment Serge described and you will find that the results show
he is correct in what he says. Then as Don has suggested, investigate
diplexing.

Bear in mind that what he describes is the kind of technique routinely
employed and studied by electronic engineers. Indeed, I'd suspect that
more than one undergrad lab may have what Serge describes as an
experiment to show this to students. It is the basis of frequency
division multiplexing in transmission line systems. :-)


Series resistance is still the same, regardless of line frequency.


Actually, not necessarily so. It is quite possible for a cable to
have a resistance that varies with frequency. :-) However even if we
ignore this, what Serge says is correct.


That experiment was to illustrate a concept, not specifics. The
principle is exactly the same.

Only for the specific case you gave. The snag is that loudspeakers aren't
simply resistors.

Slainte,

Jim

I think that there is a far more fundamental problem at work here,
Jim. Glenn does not appear to understand that what we have is a simple
voltage divider, comprising the cable and the speaker impedance. A 1
ohm cable, combined with an 8 ohm speaker will result in a loss of
about a dB at all frequencies, and it doesn't matter what signals are
present.

If the effect he is describing were to be real, then picture a 1kHz
signal in combination with a 10Hz signal. The current due to the 10Hz
would be changing from a maximum to zero 20 times per second, so the
loss at 1kHz would be changing 20 times per second. The 1kHz would
actually be amplitude modulated by the 10Hz, rather than simply
superposed, which we know to be the case. His misunderstanding of the
physics really is happening at a rather fundamental level.

d

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

bi-wire config question
 

In article , Glenn
Richards wrote:
Don Pearce wrote:


Also, most crossovers I've seen often only have a series inductor (for
LF) or series capacitor (for HF), and don't bother strapping L or C
across the load.

Well, most of the speaker crossovers I've seen were far more complex than
that...

Admittedly some do,

I wonder if anyone has any reliable figures for just what fraction of the
models of speaker on sale are as simple as you imply? It would seem that my
experience differs from yours.

Of course, Spice could be totally invalid along with a couple of
hundred years of theory, I suppose...

So how do you explain the fact that when the speakers are bi-wired they
sound better (clearer and sharper treble, more detail etc)? And when
single-wired they sound muddy by comparison?

Please give us details of some reliable reports of tests that were carried
out in a way that allows their results to be assessed as evidence and
which support what you claim. :-)

Until such time, your use of the term "fact" above may have to be regarded
with some caution... It may mean "error", or "for some other reason that
didn't occur to the listener at the time".

Hint: the standard uk.rec.audio cop-out of "it's all in your mind" is
not a valid response.

Alternative hint: Simply reporting along the lines of, "I listened to A,
then listened to B, and decided I could hear a difference" isn't reliable
evidence for what you assert. :-)


Of course it's all "in your mind", your ear only gathers sound and turns
it into electrical signals. It's your mind (or more technically your
brain) that interprets those electrical signals as noises, whether
pleasant or unpleasant. Just in case you feel like getting pedantic.

Also for the 'pedants': You may also have to bear in mind a variety of
uncorrelated variables, some of which have already been mentioned in this
thread. These mean that unless a listening test is carried out in an
appropriate way that takes these into account, we may simply be unable to
tell if a claim that an 'audible difference' is to due the 'reason'
asserted has any worth. Alas, a result which could mean anything, may mean
nothing at all - regardless of being called a 'fact'.


Remember that computers do what you tell them to do, not what you want
them to do. So if your model isn't tying up with the observed effects
then your model is obviously wrong.

This assumes that the claims about "observed effects" are based on a test
method, etc, that was relevant and reliable for the purpose. It is, alas,
quite easy to design poor tests which then return misleading 'results', or
ones the people involved interpret incorrectly. The classic example being
the kind of "magazine reviewer's test" I described above. Unfortunately,
people make assertions, but may not give the relevant details of how they
arrived at their conclusions. In such cases the 'facts' may have no
assessable meaning or value and become indistinguishable from an 'opinion'
presented as a 'fact'.

I've seen many models/analyses/theories of things which were utter twaddle.
However I've also seen many experimental/test/measurement arrangements and
protocols that were simply not fit for purpose and so returned nonsensical
or useless results. e.g. Lost count years ago of how many flawed
experiments I've seen reported that 'proved' faster-than-light propagation
in free space. Would be nice if it were true, but examination of the
experimental proceedure dissapoints... Sometimes with subtle flaws,
sometimes laughable ones. :-)

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

bi-wire config question
 

Don Pearce wrote:
On Sun, 18 Jun 2006 13:36:03 +0100, Jim Lesurf
wrote:

In article , Glenn
Richards wrote:
Serge Auckland wrote:
No it isn't! Your experiment is being done with dc. Repeat the
experiment with 50Hz to one bulb and 10kHz to the second bulb, both
bulbs being fed through a single amplifier and fed through a simple
capacitor or inductor "crossover". You will now see that the bulbs
don't change their brightness.
Makes no difference, AC or DC.
Do the experiment Serge described and you will find that the results show
he is correct in what he says. Then as Don has suggested, investigate
diplexing.

Bear in mind that what he describes is the kind of technique routinely
employed and studied by electronic engineers. Indeed, I'd suspect that
more than one undergrad lab may have what Serge describes as an
experiment to show this to students. It is the basis of frequency
division multiplexing in transmission line systems. :-)


Series resistance is still the same, regardless of line frequency.

Actually, not necessarily so. It is quite possible for a cable to
have a resistance that varies with frequency. :-) However even if we
ignore this, what Serge says is correct.


That experiment was to illustrate a concept, not specifics. The
principle is exactly the same.
Only for the specific case you gave. The snag is that loudspeakers aren't
simply resistors.

Slainte,

Jim

I think that there is a far more fundamental problem at work here,
Jim. Glenn does not appear to understand that what we have is a simple
voltage divider, comprising the cable and the speaker impedance. A 1
ohm cable, combined with an 8 ohm speaker will result in a loss of
about a dB at all frequencies, and it doesn't matter what signals are
present.

If the effect he is describing were to be real, then picture a 1kHz
signal in combination with a 10Hz signal. The current due to the 10Hz
would be changing from a maximum to zero 20 times per second, so the
loss at 1kHz would be changing 20 times per second. The 1kHz would
actually be amplitude modulated by the 10Hz, rather than simply
superposed, which we know to be the case. His misunderstanding of the
physics really is happening at a rather fundamental level.

d

Absolutely! Glenn's theory would only be valid if cables were
non-linear, but we know that cables are extremely linear, pretty much to
the limits of measurement, so no modulation can take place.

S.

bi-wire config question
 

tony sayer wrote:

'ere guv, how can I bi- or tri wire me ESL63's cos if the squirrelsounds is
right.. I want some of what he's on:))

You would be better off multi-amping them.
Get rid of that poxy HT delay line and replace it with a digital one
driving a separate amp and transformer for the centre and each annulus
and bob's your uncle.

--
Eiron

No good deed ever goes unpunished.

bi-wire config question
 

Don Pearce wrote:

Good grief - there really is no end to it.
OK, I've done all I can - anybody else feel like trying?

Come up with a computer model that matches the observed effects and I
might start taking you seriously.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

Glenn Richards wrote:

Don Pearce wrote:

OK Glenn, maybe you can't be bothered (yeah, right) but I can. I've
done the work for you and simulated the two effects - biwire, or
parallel wire, joined at the far end - in PSpice. The results
vindicate my position completely.

No they don't.

You've only placed a "lossy" cable on one leg of the speaker cable. So
you've got effectively a 5 metre run of cable from the positive speaker
output, then a short (as close to zero ohms as possible) run back to the
ground point on the amplifier.

God almighty ! Don't you know that's the same as modelling with the resistance
equally distributed ?

Graham

bi-wire config question
 

On Sun, 18 Jun 2006 20:23:43 +0100, Pooh Bear
wrote:



Glenn Richards wrote:

Don Pearce wrote:

OK Glenn, maybe you can't be bothered (yeah, right) but I can. I've
done the work for you and simulated the two effects - biwire, or
parallel wire, joined at the far end - in PSpice. The results
vindicate my position completely.

No they don't.

You've only placed a "lossy" cable on one leg of the speaker cable. So
you've got effectively a 5 metre run of cable from the positive speaker
output, then a short (as close to zero ohms as possible) run back to the
ground point on the amplifier.

God almighty ! Don't you know that's the same as modelling with the resistance
equally distributed ?

Graham

He knows nothing of how to determine what is a legitimate abstraction
for modelling purposes. He doesn't carry the pictures in his head of
how things interact, where currents flow etc.

d

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

bi-wire config question
 

Eiron wrote:

Come up with a computer model that matches the observed effects and
I might start taking you seriously.
Demonstrate your observed effects in a DBT test with an independent
witness and we might start taking you seriously.

Already been through all that some time ago (albeit single blind tests).
If there really is no difference then you won't be able to hear anything
on a single blind test, never mind double blind.

But apparently the way I carried out the test was invalid according to
some technicality made up by someone in here (I forget who). Like, who
elected you supreme commander anyway?

And once again a discussion in here turns into a slanging match.
sarcasm Would you all kindly shut the f*** up, your constant bitching
is drowning out the music. /sarcasm

Anyway... as long as the self-appointed high and mighty brigade persist
on rubbishing anyone saying they've heard differences like this, those
of us that can (and do) hear a difference in the sound will continue to
regard the likes of Don Pearce etc as sanctimonious hypocrites.

The fact remains that many people can and do hear differences between
different cables. As I've said before, I was always highly sceptical
until I was given a very convincing demonstration of the differences.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

On Sun, 18 Jun 2006 21:11:47 +0100, Glenn Richards
wrote:

Eiron wrote:

Come up with a computer model that matches the observed effects and
I might start taking you seriously.
Demonstrate your observed effects in a DBT test with an independent
witness and we might start taking you seriously.

Already been through all that some time ago (albeit single blind tests).
If there really is no difference then you won't be able to hear anything
on a single blind test, never mind double blind.

But apparently the way I carried out the test was invalid according to
some technicality made up by someone in here (I forget who). Like, who
elected you supreme commander anyway?

And once again a discussion in here turns into a slanging match.
sarcasm Would you all kindly shut the f*** up, your constant bitching
is drowning out the music. /sarcasm

Anyway... as long as the self-appointed high and mighty brigade persist
on rubbishing anyone saying they've heard differences like this, those
of us that can (and do) hear a difference in the sound will continue to
regard the likes of Don Pearce etc as sanctimonious hypocrites.

The fact remains that many people can and do hear differences between
different cables. As I've said before, I was always highly sceptical
until I was given a very convincing demonstration of the differences.

Glenn, you have never been one to let anything as mundane as a fact
get in the way of your beliefs. Nice line in sanctimonious piety, by
the way.

d

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

bi-wire config question
 

Don Pearce wrote:

Glenn, you have never been one to let anything as mundane as a fact
get in the way of your beliefs. Nice line in sanctimonious piety, by
the way.

More projecting I see...

But since you're bringing facts into this, how about this:

Fact - many people (myself included) can and do hear differences in
cable sound.

Fact - other people can't. That doesn't mean those differences aren't
real. It just means that some people can't hear them.

A case in point being my ex-girlfriend. She honestly could not tell the
difference between a £99 midi system and 5 grand's worth of separates.
Other than "your system goes louder".

Yes, that's correct, the only difference she could hear between her £99
midi system and my Arcam setup was that mine "goes louder".

Now on the rare occasions I heard her low-fi all I could hear was
speaker cabinet resonance, harmonic distortion and a complete lack of
dynamics. But she couldn't hear the difference.

Those differences were there all right. She just couldn't hear them.

And until people like you accept that, these pointless slanging matches
will continue. Let me give you a quick lesson:

Correct: "I've never heard a difference between speaker cables."

Incorrect: "Speaker cables make no difference to the sound."

The important thing to remember is that not observing an effect does not
in this case disprove, but observing the effect proves. The only time a
lack of observing an effect will disprove is if the results are 100%
consistent - by which I mean independent and repeatable. Which clearly
they aren't, as so many people can hear these differences.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

Bob Latham wrote:

Just for a moment or two can we put aside blind listening test etc.
and imaginings please.

You'll never be able to do that. You'll always get the likes of Don
Pearce ranting about "doing the maths" and posting bull**** plots from
some computer simulation to try and disprove anything you say... rather
than actually using the software to figure out why these things are
happening.

What we found was that the Chord Odyssey cable made my speakers sound
sweeter for want of a better expression. The did tend to shout a
little on some choral works for example. Odyssey definitely seemed to
reduce this and make it more relaxed to listen to. As an aside they
weigh an absolute ton, the weight never fails to surprise me.

Careful, you'll have the thought police down on you like a ton of bricks
(or should that be a ton of Odyssey cables?)...

For what it's worth, I believe you. I use Chord Rumour 4 on the front
L/R and centre speakers, and it does sound fantastic. I tend to like
quite laid back music, and there's an active sub for the really low bass
anyway, so I don't have the lack of slam in the bass that you described.
But I can see how tri-wiring using a heftier cable for the LF would
solve your problem.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

On Sun, 18 Jun 2006 22:09:31 +0100, Glenn Richards
wrote:

Don Pearce wrote:

Glenn, you have never been one to let anything as mundane as a fact
get in the way of your beliefs. Nice line in sanctimonious piety, by
the way.

More projecting I see...

But since you're bringing facts into this, how about this:

Fact - many people (myself included) can and do hear differences in
cable sound.


You haven't established this as fact - you have simply asserted it.
Not enough, I'm afraid. Establishing something as fact requires proof.

Fact - other people can't. That doesn't mean those differences aren't
real. It just means that some people can't hear them.


Or they might be lying to you, you know - winding you up by saying
they couldn't hear a difference when they could really. Everybody in
the world might be part of a conspiracy against you.

A case in point being my ex-girlfriend. She honestly could not tell the
difference between a £99 midi system and 5 grand's worth of separates.
Other than "your system goes louder".

Yes, that's correct, the only difference she could hear between her £99
midi system and my Arcam setup was that mine "goes louder".

Now on the rare occasions I heard her low-fi all I could hear was
speaker cabinet resonance, harmonic distortion and a complete lack of
dynamics. But she couldn't hear the difference.


She obviously didn' invite you round that much then - did you insult
her by dissing her hi fi?

Those differences were there all right. She just couldn't hear them.

And until people like you accept that, these pointless slanging matches
will continue. Let me give you a quick lesson:

Correct: "I've never heard a difference between speaker cables."

Incorrect: "Speaker cables make no difference to the sound."


Right both times. Speaker cables can and do make a difference to
sound. You've been told this over and over again.

The important thing to remember is that not observing an effect does not
in this case disprove, but observing the effect proves. The only time a
lack of observing an effect will disprove is if the results are 100%
consistent - by which I mean independent and repeatable. Which clearly
they aren't, as so many people can hear these differences.

Demonstrating the observation proves - asserting it does not. And you
have your experimental stuff all screwed up as usual. If you want to
prove an effect, you need to demonstrate that it is repeatably
observable.

d

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

bi-wire config question
 

Don Pearce wrote:

Now on the rare occasions I heard her low-fi all I could hear was
speaker cabinet resonance, harmonic distortion and a complete lack
of dynamics. But she couldn't hear the difference.
She obviously didn' invite you round that much then - did you insult
her by dissing her hi fi?

She didn't have a hi-fi. Or even a mid-fi. Low-fi was about the only way
to describe it.

Needless to say she didn't play it that much. I think it got turned on
about 3-4 times while I was round.

The interesting thing is that although she said she couldn't hear any
difference between her low-fi and my setup, she said that for some
reason she enjoyed hearing music more at my place.

So clearly she was *hearing* the differences, just not *perceiving* them.

Right both times. Speaker cables can and do make a difference to
sound. You've been told this over and over again.

You said they didn't. Now you're admitting that they do.

So if you're now agreeing that speaker cables can and do make a
difference, does it not follow that bi-wiring will sound different to
single-wiring?

Ignoring the maths for a moment and concentrating entirely on the sound,
if as you're suggesting bi-wiring produces a less accurate sound, but
that sound is actually more pleasant, surely it then makes sense to bi-wire?

It's the same principle as solid state vs valves. Solid state, when it
distorts, causes distortion on the even harmonics. Valve kit distorts on
the odd harmonics. And distortion on odd harmonics can actually sound
quite good (just ask any rock guitarist).

The bottom line with hi-fi is really quite simple - does it sound good?
If bi-wiring sounds better than single-wiring then bi-wire. If the
system sounds better with the bridging straps left on (so single-wired
but effectively with thicker cable) then leave the bridging straps on.
If your speakers sound better toed in 20 degrees (even though the
manufacturer recommends a toe-in of 5 degrees) then toe them in 20 degrees.

With studio monitoring equipment the goal is to get the most accurate
sonic representation of what's "on the wire". With PA the goal is to
fill a space with sound. And with hi-fi the goal is to get the best and
most desirable sound to actually listen to the music. Which means that
for hi-fi the "rules" can occasionally be broken - and as described
above if it sounds better by doing things differently then do things
differently.

A few years ago I had an amplifier (Ferrograph F307) that actually
sounded better if you ran a 3-core cable from the amp to the speakers,
splitting it halfway between the two speakers into two twin core cables,
with a common return back to the amplifier. (This arrangement obviously
won't work with a bridged amp!) It should have sounded wrong, but on
this particular amp and the particular speakers I was using at the time
it actually sounded better to do things that way.

And at about the same time, I took a smaller pair of speakers, connected
them in series then connected the free ends across the positive
terminals of the speaker outputs, thereby feeding the smaller speakers
with the L-R difference signal. Placing these speakers some way behind
the listening position gave quite an effective surround sound effect.
Purists would have had a heart attack, but it worked, and was a lot of fun.

Horses for courses, I guess.

--
Glenn Richards Tel: (01453) 845735
Squirrel Solutions http://www.squirrelsolutions.co.uk/

IT consultancy, hardware and software support, broadband installation

bi-wire config question
 

"Glenn Richards" wrote in
message
Ok, for those people that still don't "get it", here's an
experiment that will demonstrate visually what's going on:

Take a 12V DC power supply (one of those bench PSUs
capable of supplying several amps will suffice) and a 12V
1W bulb (any type will do, it's easier to perform the
experiment using a MES bulb and batten holder with screw
terminals though).

Connect the bulb to the power supply using 5 metres of
13-strand zip wire and power up. Observe the brightness
of the bulb.

Now take a second bulb and holder, and attach a few
inches of the same wire to the second holder. Connect the
second bulb in parallel with the first so that it is
"chained" from the first bulb, ie you've got 5m of cable
from PSU to first bulb, then a few inches from the first
bulb to the second bulb. Make this connection with the
power turned on.

As you connect the second bulb, you'll see the first
bulb's brightness decrease. This is caused by a voltage
drop in the cable. Disconnect the second bulb and the
brightness of the first will increase again.

Unfortunately this experiement is irrelevant to speakers, because in a
speaker there is a crossover which is frequency-selective.

bi-wire config question
 

"Glenn Richards" wrote in
message
Don Pearce wrote:

Good grief - there really is no end to it.
OK, I've done all I can - anybody else feel like trying?

Come up with a computer model that matches the observed
effects and I might start taking you seriously.

That's just the problem - without proper listening tests which you refuse to
perform Glenn, there are no reliable observed effects.

bi-wire config question
 

"Glenn Richards" wrote in
message
. uk
Serge Auckland wrote:

No it isn't! Your experiment is being done with dc.
Repeat the experiment with 50Hz to one bulb and 10kHz to
the second bulb, both bulbs being fed through a single
amplifier and fed through a simple capacitor or inductor
"crossover". You will now see that the bulbs don't
change their brightness.

Makes no difference, AC or DC. Series resistance is still
the same, regardless of line frequency. That experiment
was to illustrate a concept, not specifics. The principle
is exactly the same.

That's where you are over-simplifying, Glenn.