The damping factor and the sound of real music
 

Bob.

Unless you must have it louder there wouldn't be any point and as said
the point source will be sodded up....
--
Tony Sayer

It depends what you're doing whether "the point source will be sodded
up". For instance, Bessel is a form of stacking in which the point
source, far from being "sodded up" is enhanced. For another, several
of the stacking schemes for ESL63 and similar (for which it becomes
even less necessary, but I'm just humouring Poopie because it is
Christmas) I explained are for very grand or even public rooms, in
which a tiny loss in potential quality will not be noticed because no
one will sit down to listen for it, and the overwhelming quality of
the stats *will* be noticed. For yet another, it is easy to stack the
ESL63 and derivatives in pairs so that the point source of one
precisely meets the point of origin of the other, which is only
notionally possible, and only at one listening point, for any other
type of speakers (especially multiple cones!), the upshot being that
ESL-63 is probably the most stackable speaker there is...


Yeabut how can you have more than the one -point- source?....


Its physically impossible unless there is another dimension your keeping
from us;?...

--
Tony Sayer

The damping factor and the sound of real music
 

I totally disagree. Everything being equal good stereo adds considerably
to the enjoyment of pretty well any music or indeed reproduced sounds. It
is of course more difficult to get good stereo in an average room and
possibly also to record it. Certainly to reproduce it on early media which
had to be mono compatible.


Both FM radio and LP suffered flaws through the
adoption of stereo.

And of course digital Radio adopts better to Mono than Stereo;!....
--
Tony Sayer

The damping factor and the sound of real music
 

In article , Fleetie
scribeth thus
"tony sayer" wrote
Yes but that was the ESL57 series and quite well that worked, but the
modern designs are sufficient for purpose if you want to hear what
really went on;)...

Not according to the "Hi-Fi Choice" article I read in the late 80s.
It had a picture of his room, and in it were (at least) 2 pairs
of stripped-down (grilles removed) ESL-63s, arranged so that for
each channel there were 2 speakers right next to each other, but
set at 90 degrees to each other.

I forget his name right now but I know it's still somewhere in my
memory. Oh yes, "ARA", I think. Alastair Robertson-Aikman or something?


Hi-fi jurno was he then?....

Martin

--
Tony Sayer

The damping factor and the sound of real music
 

tony sayer wrote:
Bob.
Unless you must have it louder there wouldn't be any point and as said
the point source will be sodded up....
--
Tony Sayer
It depends what you're doing whether "the point source will be sodded
up". For instance, Bessel is a form of stacking in which the point
source, far from being "sodded up" is enhanced. For another, several
of the stacking schemes for ESL63 and similar (for which it becomes
even less necessary, but I'm just humouring Poopie because it is
Christmas) I explained are for very grand or even public rooms, in
which a tiny loss in potential quality will not be noticed because no
one will sit down to listen for it, and the overwhelming quality of
the stats *will* be noticed. For yet another, it is easy to stack the
ESL63 and derivatives in pairs so that the point source of one
precisely meets the point of origin of the other, which is only
notionally possible, and only at one listening point, for any other
type of speakers (especially multiple cones!), the upshot being that
ESL-63 is probably the most stackable speaker there is...


Yeabut how can you have more than the one -point- source?....


Its physically impossible unless there is another dimension your keeping
from us;?...

Jute knows more about ESL63s than any man alive.
"You can get wonderfully inflated readings from the ESL63 by
measuring dead centre and 12 inches in front of it, where it has a faux
point source. Of course, that would be the same as measuring *behind*
the speaker, for the ESL63 is a dipole which has the faux point source
each side, and the sound at the listening position is from the cone
with its point behind the speaker."
( http://groups.google.com/group/rec.a...27f901c4507c3d )

So I guess he is stacking his ESLs one in front of the other, 2 feet apart.
You either like the sound of a comb filter or you don't....

--
Eiron.

The damping factor and the sound of real music
 

On Dec 26, 9:37*pm, tony sayer wrote:
Bob.

Unless you must have it louder there wouldn't be any point and as said
the point source will be sodded up....
--
Tony Sayer

It depends what you're doing whether "the point source will be sodded
up". For instance, Bessel is a form of stacking in which the point
source, far from being "sodded up" is enhanced. For another, several
of the stacking schemes for ESL63 and similar (for which it becomes
even less necessary, but I'm just humouring Poopie because it is
Christmas) I explained are for very grand or even public rooms, in
which a tiny loss in potential quality will not be noticed because no
one will sit down to listen for it, and the overwhelming quality of
the stats *will* be noticed. For yet another, it is easy to stack the
ESL63 and derivatives in pairs so that the point source of one
precisely meets the point of origin of the other, which is only
notionally possible, and only at one listening point, for any other
type of speakers (especially multiple cones!), the upshot being that
ESL-63 is probably the most stackable speaker there is...

Yeabut how can you have more than the one -point- source?....

Its physically impossible unless there is another dimension your keeping
from us;?...

--
Tony Sayer

Put a single ESL63 or derivative -- minimum case, yeah? one speaker
only, okay? -- in the middle of an empty room. Play music. Stand in
front of the speaker. Hear the point source. Walk around the music.
Hear the point source on the other side of the speaker. So what do you
have? One speaker, two point sources.

Now put two -63s there parallel to each other and about twelve inches
apart. Play music. Hear the point source. Walk around the music. Hear
the point source on the other side of the speaker. So what do you
have? One "combined" speaker, two point sources.

The laws of physics remain intact; I won't be messing with them until
the phone company manages to repair my blue callbox...

Andre Jute
"I was at a board meeting for the LA Chapter of the Audio Engineering
Society last night on XM Satellite radio audio and data transmission.
Sadly, we missed you there, and at the SMPTE and Acoustical Society
recent meetings as well. Everyone was asking, 'Where is that wonderful
Andre Jute? The world just doesn't rotate without him...'" -- John
Mayberry, Emmaco

The damping factor and the sound of real music
 

On Wed, 26 Dec 2007 13:21:12 +0000 (GMT), Jim Lesurf
wrote:

I think he deliberately aimed some pairs well away
from the listener direction to get a controlled added 'ambience', etc.

I've never understood this technique. It seems to display basic
misunderstanding of how stereo reproduction works.

The damping factor and the sound of real music
 

As per my other postings, this is trimmed to just be to uk.rec.audio. I do
this as I don't read the other groups to which the thread has been
crossposted, and am happy to just have my comments appear in uk.rec.audio.

In article
,
Andre
Jute wrote:
On Dec 26, 9:37 pm, tony sayer wrote:


Yeabut how can you have more than the one -point- source?....


Put a single ESL63 or derivative -- minimum case, yeah? one speaker
only, okay? -- in the middle of an empty room. Play music. Stand in
front of the speaker. Hear the point source. Walk around the music. Hear
the point source on the other side of the speaker. So what do you have?
One speaker, two point sources.

Now put two -63s there parallel to each other and about twelve inches
apart. Play music. Hear the point source. Walk around the music. Hear
the point source on the other side of the speaker. So what do you have?
One "combined" speaker, two point sources.

It is worth bearing in mind that the ESL63 family of designs only
approximate to a 'point source' with some specific restrictions regarding
their behaviour and use. For that reason the above may mislead as it
over-simplifies.

In physics, a genuine 'point source' is one which radiates in a manner that
shows no 'signature' of having any physical size or 'internal structure'.
This leads to a set of standard properties which include:

1) From wherever in space you pick up the signals from a 'point source' the
radiation always seems to come from the same point source location.

2) The signal level tends to fall away with the familiar square law
dependence, and does so in the same manner in all directions. So all
locations on a sphere centered on the point source will experience the same
signal level.

It is also common to add something like

3) That the above properties show no spatial or geometric variations with
signal frequency over the range of interest. (This is related to the above
via some expectations from the properties of coherence, but obvious depend
on the spectrum of the power being generated at the point. )

The ESL63 family does not adhere to these conditions without any
qualifications. Instead it exploits symmetry to mimic them to some extent
*for listeners at a 'reasonable distance' in locations in some directions*.

The speakers are a phased array with nominal circular/rectangular symmetry
with their elements in a plane. The result is that symmetry allows them, by
design, to approach 'point source' behaviour for receiving locations along
(or near to) the axis normal to the speaker's center of symmetry. However
this tends to break down if you get too close to the array, or move to a
location which is not close enough to the axis.

So for someone on axis at a reasonably distance, the effect is similar to a
point source in the specific sense that the radiation seems to come from
the same direction (along the axis) at all frequencies. But this may not
hold under other conditions if you move around, and the above
characteristics for a nominal point source won't hold everywhere.

The speakers have a better controlled radiation pattern than many other
speakers, but they still radiate with a pattern that varies with frequency.

The above matters in the context of trying to use two speakers 'stacked' or
used in tandem as a coherent combination.

If the speakers were true point sources, then using a pair being driven in
the same way would modify the resulting radiation pattern in a frequency
dependent manner, further altered by 'near field' effects of the arrays.
Since the ESL63 family are *not* genuine point sources, this behaviour is
modified by their tendency to 'beam' to a controlled extent, and by the way
the frequency response varies in a complex way off-axis or when too close.

The meaning of 'near field' also alters with multiple speakers as the
speaker spacing adds another factor to this, with a dimension comparable to
the speaker spacing rather than the size of the individual speaker
elements.

In the context of using them in a room, the results may well be quite
different to useing a single speaker, but this all will depend critically
on all the details of the situation.

In situations where you 'aim' each speaker at the listener location, and
ensure they are exactly the same distance from that location, these effects
at that location may be minimised *provided that the room reflections do
not cause problems*. This follows from symmetry as the listener is on the
bisector of the line connecting the two speaker centers, etc. If you only
have one ear, and are in free space, this would probably work neatly. ;-

However the changes in the overall radiation pattern caused by the coherent
superposition of the output from the two speakers will mean the room
interaction will be driven with a different signal than if using one
speaker, so that may lead to a change of some kind. Plus the usual risk
that the effect will differ from one ear location to the other,
particularly when you head is in between.

The good news here is that the ESL63 family are *not* point sources, so by
aiming them at the listener you help reduce the power in other directions
that might then lead to problems via room reflections. :-)

If you don't follow the above then the results may be rather different to
using one speaker. Hard to say more due to the dependence on all the details.

I have never felt any urge to use stacked pairs of ESL63s as one stereo
pair seem superb to me, and getting the best results in a room even for
that 'simple' arrangement took me many months of experiment. So I am
personally happy to 'pass' on bothering to try to use stacked or combined
sets of speakers. ;- I am sure that in the right circumstances the
results could be very good. Just that I am too old to bother. ;-

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

The damping factor and the sound of real music
 

In article , Laurence Payne
NOSPAMlpayne1ATdsl.pipex.com wrote:
On Wed, 26 Dec 2007 13:21:12 +0000 (GMT), Jim Lesurf
wrote:

I think he deliberately aimed some pairs well away from the listener
direction to get a controlled added 'ambience', etc.

I've never understood this technique. It seems to display basic
misunderstanding of how stereo reproduction works.

I think the listening room he used was much larger than the domestic rooms
most of us use, and IIRC was acoustically treated, etc. So the room reverb
might have helped with a convincing stereo image - rather than upsetting it
as may be the case in poor rooms. However I never heard his system, so can
only guess.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

The damping factor and the sound of real music
 

In article
s.com, Andre Jute scribeth thus
On Dec 26, 9:37*pm, tony sayer wrote:
Bob.

Unless you must have it louder there wouldn't be any point and as said
the point source will be sodded up....
--
Tony Sayer

It depends what you're doing whether "the point source will be sodded
up". For instance, Bessel is a form of stacking in which the point
source, far from being "sodded up" is enhanced. For another, several
of the stacking schemes for ESL63 and similar (for which it becomes
even less necessary, but I'm just humouring Poopie because it is
Christmas) I explained are for very grand or even public rooms, in
which a tiny loss in potential quality will not be noticed because no
one will sit down to listen for it, and the overwhelming quality of
the stats *will* be noticed. For yet another, it is easy to stack the
ESL63 and derivatives in pairs so that the point source of one
precisely meets the point of origin of the other, which is only
notionally possible, and only at one listening point, for any other
type of speakers (especially multiple cones!), the upshot being that
ESL-63 is probably the most stackable speaker there is...

Yeabut how can you have more than the one -point- source?....

Its physically impossible unless there is another dimension your keeping
from us;?...

--
Tony Sayer

Put a single ESL63 or derivative -- minimum case, yeah? one speaker
only, okay? -- in the middle of an empty room. Play music. Stand in
front of the speaker. Hear the point source. Walk around the music.
Hear the point source on the other side of the speaker. So what do you
have? One speaker, two point sources.

Yeabut which point source are you on about PW only ever mentioned One
point source;!.,..

--
Tony Sayer

The damping factor and the sound of real music
 

In article , Jim Lesurf jcgl@st-
and.demon.co.uk scribeth thus
As per my other postings, this is trimmed to just be to uk.rec.audio. I do
this as I don't read the other groups to which the thread has been
crossposted, and am happy to just have my comments appear in uk.rec.audio.

In article
,
Andre
Jute wrote:
On Dec 26, 9:37 pm, tony sayer wrote:


Yeabut how can you have more than the one -point- source?....


Put a single ESL63 or derivative -- minimum case, yeah? one speaker
only, okay? -- in the middle of an empty room. Play music. Stand in
front of the speaker. Hear the point source. Walk around the music. Hear
the point source on the other side of the speaker. So what do you have?
One speaker, two point sources.

Now put two -63s there parallel to each other and about twelve inches
apart. Play music. Hear the point source. Walk around the music. Hear
the point source on the other side of the speaker. So what do you have?
One "combined" speaker, two point sources.

It is worth bearing in mind that the ESL63 family of designs only
approximate to a 'point source' with some specific restrictions regarding
their behaviour and use. For that reason the above may mislead as it
over-simplifies.

In physics, a genuine 'point source' is one which radiates in a manner that
shows no 'signature' of having any physical size or 'internal structure'.
This leads to a set of standard properties which include:



1) From wherever in space you pick up the signals from a 'point source' the
radiation always seems to come from the same point source location.

An Isotropic radiator in fact!....
--
Tony Sayer