"George M. Middius" cmndr [underscore] george [at] comcast [dot] net wrote
in message ...


surf said:

You're bull****ting, Arn. You know you've attacked (been hostile to,
abusive to, nasty to, etc) people because they've merely disagreed with
you. Please be honest.

I'd like to see that, too. Also, it would be nice if Mickey smartened up,
and the lesser 'borgs admitted their hypocrisy for flogging aBxism when
they've never, ever partaken, even a single time.

Which has nothing to do with understanding the fact that ABX is valid for
what it is used for.


We're all smart enough to know what dickhead you are.

After all that, the ayatollahs in Iran will convert to Judaism, and the
Mexican government will suddenly develop a collective conscience and go
after the kidnapper gangs. I can hardly wait!

When will you start talking about audio?

Goofball_star_dot_etal wrote:
On 15 Dec 2005 13:00:07 -0800, "John Atkinson"
wrote:
ScottW wrote:
Why not address this question... Should a speaker support have any
significant effect on sound quality?

I am sorry, I don't comprehend the question. "Should they?" The fact is
that they do.

So.. Are Powell's measurements typical? :-)
http://www.glowfoto.com/viewimage.ph...=2301&srv=img2

I doubt it. His graph is showing very large farfield differences that
cover
octave-wide and greater frequency regions, that are several orders of
magnitude greater than anything I have encountered. I suspect that
either the speaker or the microphone were inadvertently moved between
the two measurement conditions.

I suggest that it should not beyond its impact on location or height.
If the support does dramatically impact the sound by altering cabinet
response... then the cabinet design and/or fabrication is IMO grossly
deficient.

Of the almost 600 loudspeakers I have measured over the past 15
years, I can count on the fingers of one hand the number that have
_not_ suffered from panel resonances in their enclosures to a
measurable and often audible extent. You may regard these designs
as "grossly deficient"; i am merely observing how things actually
are in the real world where the designer is limited by his budget
regarding what he can achieve in this area.

So.. Do fancy stands cure the pesky vibrations or just make them
different?

"Fancy" stands? A good stand need not be expensive or
complicated. It needs merely to be rigid and non-resonant (and
the right height). Ideally, it should have high internal damping
without compromising the rigidity. I use single-pillar metal designs
with that pillar filled with a mixture of sand and lead shot. The
amount of vibration in the pillar induced by a problematic speaker
coupled to the stand's top plate with spikes (measured with an
accelerometer) was considerable before I added the filling. After,
it was pretty much inert.

As to curing or changing, this is what I addressed in the article I
referenced in an earlier post, as well in another post. And my opinion
is
that the material used to couple the speaker to the stand is of
primary importance.

Whether, with a specific speaker, you want to let the panel resonances
ring
maximally or try to damp them out of existence is going to depend on
the radiating area affected and the amplitude, frequency, and Q of the
resonance and how much the Q and amplitude can be reduced. As
Floyd Toole has pointed out, low-Q small-amplitude resonances are
more easily detected sonically annoying than high-amplitude resonances
of very high Q. There is also the rule of thumb to consider that a
resonance
needs to be stimulated with a number of cycles equal to its Q to be
maximally stimulated.

All I can advise audiophiles is that if they suspect something is
causing
problems -- in the worst case I have heard music sound out of tune in a
narrow midrange band due to the "pulling" effect of an undamped
panel resonance -- they should experiment with stands and interfacing.

And I fail to grasp what is so controversial about anything I have said
on this subject.

John Atkinson
Editor, Stereophile

ScottW wrote:
John Atkinson wrote:
ScottW wrote:
Should a speaker support have any significant effect on sound
quality?

I am sorry, I don't comprehend the question. "Should they?"

Yes...should they? I suggest that a complicated and expensive
stand to address cabinet deficiencies is not likely to be effective.
Put the money into the cabinet and properly address the problem.

I don't disagree but this is not an option for the audiophile unless
he builds his own speakers. Experimenting with stands and
interfacing is cheap, easy, and can be very effective with
speakers that have audible problems with cabinet panel
resonances, as too many do, in my not inconsiderable
experience.

Another strategy is to try adding mass to the speaker, by, say,
placing a plastic bag full of sand or shot on top of it. Doesn't look
very nice, but in some cases it can shift the frequency of the
problematic resonance by just enough that it will not be as
excited as often with moden-tuned Western music. This is
what I meant in an earlier posting by "falling between the gaps."
A resonance needs to be stimulated by a number of cycles of
ist center frequency equal to its Q to be maximally stimulated;
you can reduce the efficency of that stimulation by moving
the frequency of the resonance even slightly.

John Atkinson
Editor, Stereophile

On 16 Dec 2005 07:01:28 -0800, "John Atkinson"
wrote:


Goofball_star_dot_etal wrote:
On 15 Dec 2005 13:00:07 -0800, "John Atkinson"
wrote:
ScottW wrote:
Why not address this question... Should a speaker support have any
significant effect on sound quality?

I am sorry, I don't comprehend the question. "Should they?" The fact is
that they do.

So.. Are Powell's measurements typical? :-)
http://www.glowfoto.com/viewimage.ph...=2301&srv=img2

I doubt it. His graph is showing very large farfield differences that
cover
octave-wide and greater frequency regions, that are several orders of
magnitude greater than anything I have encountered. I suspect that
either the speaker or the microphone were inadvertently moved between
the two measurement conditions.

I think the crux of the problem is that arty-farties, footballer's
wives, solicitors, bankers and even successful business men or wannabe
theoretical physicists should not be attempting to measure speakers.



I suggest that it should not beyond its impact on location or height.
If the support does dramatically impact the sound by altering cabinet
response... then the cabinet design and/or fabrication is IMO grossly
deficient.

Of the almost 600 loudspeakers I have measured over the past 15
years, I can count on the fingers of one hand the number that have
_not_ suffered from panel resonances in their enclosures to a
measurable and often audible extent. You may regard these designs
as "grossly deficient"; i am merely observing how things actually
are in the real world where the designer is limited by his budget
regarding what he can achieve in this area.

So.. Do fancy stands cure the pesky vibrations or just make them
different?

"Fancy" stands? A good stand need not be expensive or
complicated.

I'll keep a lookout for Lidl special offers.

It needs merely to be rigid

Ah. Perhaps..

and non-resonant

Ah. Tricky if it is stiff and heavy. With or without a speaker hanging
off it? Hitting it with a hammer does not count.

(and the right height).

Good point!

Ideally, it should have high internal damping
without compromising the rigidity. I use single-pillar metal designs
with that pillar filled with a mixture of sand and lead shot.

I suppose that if I can assume that a violin bridge on a chip does not
change the sound, I can not complain if people assume that sand and
lead damps stands.

The
amount of vibration in the pillar induced by a problematic speaker
coupled to the stand's top plate with spikes (measured with an
accelerometer) was considerable before I added the filling. After,
it was pretty much inert.

Perhaps it got heavier.


As to curing or changing, this is what I addressed in the article I
referenced in an earlier post, as well in another post. And my opinion
is
that the material used to couple the speaker to the stand is of
primary importance.

You might be on to something.. put the damping stuff where the movment
is.


Whether, with a specific speaker, you want to let the panel resonances
ring
maximally or try to damp them out of existence is going to depend on
the radiating area affected and the amplitude, frequency, and Q of the
resonance and how much the Q and amplitude can be reduced. As
Floyd Toole has pointed out, low-Q small-amplitude resonances are
more easily detected sonically annoying than high-amplitude resonances
of very high Q.

Peaks or troughs?

There is also the rule of thumb to consider that a
resonance
needs to be stimulated with a number of cycles equal to its Q to be
maximally stimulated.

All I can advise audiophiles is that if they suspect something is
causing
problems -- in the worst case I have heard music sound out of tune in a
narrow midrange band due to the "pulling" effect of an undamped
panel resonance -- they should experiment with stands and interfacing.


That could mean a lot of trips to the shop for nothing..

And I fail to grasp what is so controversial about anything I have said
on this subject.

Don't look at me.. I never suggested that stands could not affect the
sound, it is just that it is a very poor place to start from if you
want damp panels. For instance if the stand has a single stiff
vertical tube then there is no signifcant movement between the ends,
so no damping along the vertical axis of the stand but it could make
the floor flap. If your speaker has symmetry left/right and the side
panels are flapping like a tuning fork then you are also out of luck
(no force on stand- no effect). etc.

Goofball_star_dot_etal wrote :


"Fancy" stands? A good stand need not be expensive or
complicated.

I'll keep a lookout for Lidl special offers.

LOL !

"John Atkinson" wrote

Why not address this question... Should
a speaker support have any significant
effect on sound quality?

I am sorry, I don't comprehend the question.
"Should they?" The fact is
that they do.

So.. Are Powell's measurements typical? :-)
http://www.glowfoto.com/viewimage.ph...=2301&srv=img2

I doubt it. His graph is showing very large farfield
differences...

"farfield differences"... no, near-field, 1 meter.


that cover octave-wide and greater frequency
regions, that are several orders of magnitude
greater than anything I have encountered.

That’s because your experience is limited to
low end designs.


I suspect that either the speaker or the
microphone were inadvertently moved between
the two measurement conditions.

To quote you "One would be wrong to do so."

"I suspect" your methodology is deficient
in respect to empirical findings.


So.. Do fancy stands cure the pesky vibrations
or just make them different?

"Fancy" stands? A good stand need not be
expensive or complicated.

OSAF.


It needs merely to be rigid and non-resonant
(and the right height).

Yes at Stereophile you have make an art
form out of counting angles dancing on the
head of a pin.


Ideally, it should have high internal damping
without compromising the rigidity. I use
single-pillar metal designs with that pillar filled
with a mixture of sand and lead shot. The
amount of vibration in the pillar induced by a
problematic speaker coupled to the stand's
top plate with spikes (measured with an
accelerometer) was considerable before I
added the filling. After, it was pretty much
inert.

True, this is the low-tech approach.

Your methodology in the use of an
accelerometer is problematic.

As to curing or changing, this is what I
addressed in the article I referenced in an
earlier post, as well in another post. And
my opinion is that the material used to
couple the speaker to the stand is of
primary importance.

Agreed, however your methodology
in applying Blu-tack is also problematic,
IME.

snip theory

All I can advise audiophiles is that if they
suspect something is causing problems...
they should experiment with stands and
interfacing.

Really, how does that work? Couldn’t stands
improve an already good sounding speaker?
Your lack of empirical stand experience has
made you short sighted.


And I fail to grasp what is so controversial about
anything I have said on this subject.

Hypocrisy Noted: you find it difficult for other
not to suspend their disbeliefs while you are
unable to do the same.

"Goofball_star_dot_etal" wrote

I think the crux of the problem is that
arty-farties, footballer's wives, solicitors,
bankers and even successful business men
or wannabe theoretical physicists should not
be attempting to measure speakers.

Hehehe... where would you place in your
intellectual hierarchy? Ditch digger perhaps.


For instance if the stand has a single stiff
vertical tube then there is no signifcant
movement between the ends, so no damping
along the vertical axis of the stand but it could
make the floor flap. If your speaker has
symmetry left/right and the side panels are
flapping like a tuning fork then you are also
out of luck (no force on stand- no effect). etc.

Please take your own advice then, mr.
"wannabe theoretical physicists."

On Thu, 22 Dec 2005 18:44:43 -0500, "Powell"
wrote:


"Goofball_star_dot_etal" wrote

I think the crux of the problem is that
arty-farties, footballer's wives, solicitors,
bankers and even successful business men
or wannabe theoretical physicists should not
be attempting to measure speakers.

Hehehe... where would you place in your
intellectual hierarchy? Ditch digger perhaps.

Close.

For instance if the stand has a single stiff
vertical tube then there is no signifcant
movement between the ends, so no damping
along the vertical axis of the stand but it could
make the floor flap. If your speaker has
symmetry left/right and the side panels are
flapping like a tuning fork then you are also
out of luck (no force on stand- no effect). etc.

Please take your own advice then, mr.
"wannabe theoretical physicists."


I suppose you are a bit miffed.