"John Phillips" wrote in message


Is a 2.7 dB left-right stereo imbalance reasonable for a
loudspeaker-room interaction in a nearly symmetrical room?

You might want to swap the speakers, as its not unusual for speakers to
depart from spec by a dB or two. That means that a pair, each unit at the
opposite ends of spec, could vary this much.

My last system needed no tweaking of the left-right balance control to
get a central image.

If you want a really well-matched pair of speakers, get a eq and tweak the
channels in with it. This will address both sensitivity and frequency
response issues.

If you want a really nicely resolved central image, put in a center channel
speaker. I don't mean one of these gutted little lost puppies they sell to
the HT crowd, I mean a full-tilt speaker sitting in the middle of the other
two, or close to it. Drive it with its own power amp and a L+R matrix.

However my current system needs a 2.7 dB shift
in the balance control. I have checked the source balance and
swapped all components (including leads) and the imbalance remains in
either the room or my ears.

I assume this imbalance is a loudspeaker-room interaction. The room is
not perfectly symmetrical but not far out. An intruding chimney
breast is the main asymmetry, apart from furniture.

If you've swapped *everything* you will be especially well-advised to
consider my comments about equalizers and center speakers.

On 14 Dec 2004 07:59:46 GMT, John Phillips
wrote:

In article , Garf wrote:
With my set up it turned out to be my ears :-(

Could be with me too. I'm 47 now and the limit to my frequency range is
already down to about 14.2 kHz. There may be other deteriorations too,
I suppose.

However I understand that lateral imbalance in hearing is measured as
a difference in hearing threshold and a difference of 2.7 dB would be
considered as unimportant. More than 10 dB (as I read it from the web,
anyway) is considered significant.

I could not find any material on hearing imbalance at other than hearing
threshold levels which might contribute to my needing to use a stereo
balance control.

The reason there's little about it is that small imbalances like this
are almost always readily adapted since we use this for localization
and navigation. If you have no indications of such imbalance outside
your stereo environment, it is probably something in the system/room.
I suggest that you do a more careful frequency-by-frequency
measurement in order to distinguish a simple imbalance from a
lateralized frequency aberration.

Kal

"Kalman Rubinson" wrote in message
...
On 14 Dec 2004 07:59:46 GMT, John Phillips
wrote:

In article , Garf
wrote:
With my set up it turned out to be my ears :-(

Could be with me too. I'm 47 now and the limit to my frequency range is
already down to about 14.2 kHz. There may be other deteriorations too,
I suppose.

However I understand that lateral imbalance in hearing is measured as
a difference in hearing threshold and a difference of 2.7 dB would be
considered as unimportant. More than 10 dB (as I read it from the web,
anyway) is considered significant.

I could not find any material on hearing imbalance at other than hearing
threshold levels which might contribute to my needing to use a stereo
balance control.

The reason there's little about it is that small imbalances like this
are almost always readily adapted since we use this for localization
and navigation. If you have no indications of such imbalance outside
your stereo environment, it is probably something in the system/room.
I suggest that you do a more careful frequency-by-frequency
measurement in order to distinguish a simple imbalance from a
lateralized frequency aberration.

Kal


No, in my case it really is my ears, I'm going deaf in the right one. As for
adaptation for localisation & navigation, an imbalance of 2.7dB would not be
considered as insignificant to any specialist wrt to interpreting a "stereo"
image.

Normal limits are 0-20 dBHL (decibel Hearing Level) mild hearing loss is
diagnosed at 25--39 dBHL (me in one ear!). A 2.7dB imbalance would be 10%
(or greater dependant on the best lug hole level) imbalance from normal
levels and certainly would be noticeable in determining source and
soundstage from stereo speakers.

Nature does compensate to a degree by adaptation but in nature we do not
find artificial representations of stereo soundstages. I first noticed my
problem when I had to adjust balance to "feel comfortable" with certain
tracks, now it's all tracks and I have been diagnosed as an decrepit old
fart who's going deaf in one ear. I don't notice this much at all in any
other circumstances but eventually I know that will be able to avoid all of
my wife's nagging simply by sitting to her left! (There's always a positive
spin)

Simple test, sit with your back to the speakers, does the imbalance change?

Garf

On Tue, 14 Dec 2004 20:20:16 -0000, "Garf"
wrote:

"Kalman Rubinson" wrote in message
.. .
On 14 Dec 2004 07:59:46 GMT, John Phillips
wrote:

In article , Garf
wrote:
With my set up it turned out to be my ears :-(

Could be with me too. I'm 47 now and the limit to my frequency range is
already down to about 14.2 kHz. There may be other deteriorations too,
I suppose.

However I understand that lateral imbalance in hearing is measured as
a difference in hearing threshold and a difference of 2.7 dB would be
considered as unimportant. More than 10 dB (as I read it from the web,
anyway) is considered significant.

I could not find any material on hearing imbalance at other than hearing
threshold levels which might contribute to my needing to use a stereo
balance control.

The reason there's little about it is that small imbalances like this
are almost always readily adapted since we use this for localization
and navigation. If you have no indications of such imbalance outside
your stereo environment, it is probably something in the system/room.
I suggest that you do a more careful frequency-by-frequency
measurement in order to distinguish a simple imbalance from a
lateralized frequency aberration.

Kal


No, in my case it really is my ears, I'm going deaf in the right one. As for
adaptation for localisation & navigation, an imbalance of 2.7dB would not be
considered as insignificant to any specialist wrt to interpreting a "stereo"
image.

Normal limits are 0-20 dBHL (decibel Hearing Level) mild hearing loss is
diagnosed at 25--39 dBHL (me in one ear!). A 2.7dB imbalance would be 10%
(or greater dependant on the best lug hole level) imbalance from normal
levels and certainly would be noticeable in determining source and
soundstage from stereo speakers.

Nature does compensate to a degree by adaptation but in nature we do not
find artificial representations of stereo soundstages. I first noticed my
problem when I had to adjust balance to "feel comfortable" with certain
tracks, now it's all tracks and I have been diagnosed as an decrepit old
fart who's going deaf in one ear. I don't notice this much at all in any
other circumstances but eventually I know that will be able to avoid all of
my wife's nagging simply by sitting to her left! (There's always a positive
spin)

Simple test, sit with your back to the speakers, does the imbalance change?

Garf

I understand but I was responding regarding a 2.7dB loss, not to your
larger deficit. (Please accept sympathy on that score.) As such is
readily adapted to in the 'real world,' there is little different
about the stereo system situation. Now, put an ear plug in one ear of
a 'normal' individual and, short term, the balances are off.

Another issue is that the losses we are talking of are rarely evenly
effective across the audible range. Since it occurs initially and
mostly at higher frequencies, its interaction with loudspeakers and
room acoustics could well be different than in natural settings.

Kal

"Kalman Rubinson" wrote in message
...
On Tue, 14 Dec 2004 20:20:16 -0000, "Garf"
wrote:

"Kalman Rubinson" wrote in message
.. .
On 14 Dec 2004 07:59:46 GMT, John Phillips
wrote:

In article , Garf
wrote:
With my set up it turned out to be my ears :-(

Could be with me too. I'm 47 now and the limit to my frequency range
is
already down to about 14.2 kHz. There may be other deteriorations
too,
I suppose.

However I understand that lateral imbalance in hearing is measured as
a difference in hearing threshold and a difference of 2.7 dB would be
considered as unimportant. More than 10 dB (as I read it from the
web,
anyway) is considered significant.

I could not find any material on hearing imbalance at other than
hearing
threshold levels which might contribute to my needing to use a stereo
balance control.

The reason there's little about it is that small imbalances like this
are almost always readily adapted since we use this for localization
and navigation. If you have no indications of such imbalance outside
your stereo environment, it is probably something in the system/room.
I suggest that you do a more careful frequency-by-frequency
measurement in order to distinguish a simple imbalance from a
lateralized frequency aberration.

Kal


No, in my case it really is my ears, I'm going deaf in the right one. As
for
adaptation for localisation & navigation, an imbalance of 2.7dB would not
be
considered as insignificant to any specialist wrt to interpreting a
"stereo"
image.

Normal limits are 0-20 dBHL (decibel Hearing Level) mild hearing loss is
diagnosed at 25--39 dBHL (me in one ear!). A 2.7dB imbalance would be 10%
(or greater dependant on the best lug hole level) imbalance from normal
levels and certainly would be noticeable in determining source and
soundstage from stereo speakers.

Nature does compensate to a degree by adaptation but in nature we do not
find artificial representations of stereo soundstages. I first noticed my
problem when I had to adjust balance to "feel comfortable" with certain
tracks, now it's all tracks and I have been diagnosed as an decrepit old
fart who's going deaf in one ear. I don't notice this much at all in any
other circumstances but eventually I know that will be able to avoid all
of
my wife's nagging simply by sitting to her left! (There's always a
positive
spin)

Simple test, sit with your back to the speakers, does the imbalance
change?

Garf

I understand but I was responding regarding a 2.7dB loss, not to your
larger deficit. (Please accept sympathy on that score.) As such is
readily adapted to in the 'real world,' there is little different
about the stereo system situation. Now, put an ear plug in one ear of
a 'normal' individual and, short term, the balances are off.

Another issue is that the losses we are talking of are rarely evenly
effective across the audible range. Since it occurs initially and
mostly at higher frequencies, its interaction with loudspeakers and
room acoustics could well be different than in natural settings.

Kal

Hi Kal

have to disagree, the "norm" dbHL is zero to 20 dB, e.g lugs can clearly
identify sound at say 18dB levels = normal Mr Average.

If one lug identifies at 18dB and the other lug at 20.7dB you have a 15%
imbalance between ears, this is more than enough to have Mr Average reaching
for the balance control if the sound is a focussed from TWO separate,
equidistant sources roughly located on each side of his head (Speakers in
this case, assuming he sits on a couch looking at the wood)

It is not enough for the same Mr Average to have issues in conversation or
in location of direction as we normally listen to ONE source (plus
background noise) and hear it in both ears to locate direction.

My larger deficit is not that much larger, 21 dB in left lug, 26 in the
right and took ten years for me to visit the specialist so probably started
at a much lower, but clearly noticeable imbalance. BTW sympathy not needed,
I just had to get used to the balance knob not sitting straight up.

Don't get me wrong, hear (sic). I know the value of speaker positioning,
room characteristics et al but I did have quite a few frustrating years of
speaker and room shuffling before I went to the docs and learnt not to blame
my speakers, room or wife.

The more you love music, are passionate about the sound then the more you
will notice subtle changes and "imbalances". We (and this is true cos that's
why we read this NG) pack the wife off in the bath, kids off to bed,
silence the house and sit in our listening position to hear our music. It
has to be perfect, it has to be in perfect balance with a clear defined
soundstage, we should not be surprised that audiophiles can notice a 2-3 dB
imbalance. We are after all perfectionists.

Nice thread, thank you and goodnight

Garf

In article , Arny Krueger wrote:
"John Phillips" wrote in message


Is a 2.7 dB left-right stereo imbalance reasonable for a
loudspeaker-room interaction in a nearly symmetrical room?

You might want to swap the speakers, as its not unusual for speakers to
depart from spec by a dB or two. That means that a pair, each unit at the
opposite ends of spec, could vary this much.

I did that on first noticing the problem. The imbalance stayed with
the room or the CD+amplifier. It was after that that I did the checks
on the CD player, amplifier and cables to eliminate them.

However I have now moved a small book-case from against the wall nearly
behind one of the speakers and the imbalance has improved (I can't tell
how much immediately). I may go back and see if adjusting the speaker
position will do more good than it did previously.

If you've swapped *everything* you will be especially well-advised to
consider my comments about equalizers and center speakers.

I was eyeing a TACT adaptive room equalizer but I think I will wait for
the price to come down a bit.

--
John Phillips

"John Phillips" wrote in message


I was eyeing a TACT adaptive room equalizer but I think I will wait
for the price to come down a bit.

There are a ton of other, less-costly alternatives.

In article , Jim Lesurf wrote:
Provided the 'swap' tests showed this stayed firmly in the same 'direction'
so far as perception was concerned I assume your equipment is fine. If the
image is reasonably narrow and well defined, then it is probably OK just to
resign yourself to using the offset and getting results that then sound
fine! About all it then implies is that one speaker might be being driven a
bit harder than the other.

Well, I think I finally have it right (or close to) after all,

Having moved a small book-case I noticed an improvement. I was prompted
to go back to adjusting the speakers' positions. Now I have the stereo
image well balanced with no artificial adjustment.

It looks (from an optical perspective) like the adjustments have got the
side-wall accoustic reflection environment more symmetrical. There is
now some damping of the accoustic reflection at the right points on both
side-walls, whereas previously there was damping on only one side and
a bare wall on the other. Maybe this was the cause of the imbalance.
Some guides (e.g. from Audio Physic) make much of side-wall reflections.

Anyway, regardless of the exact issue, I guess it was the room after all.
It looks like I didn't spend long enough to position the speakers earlier
before resorting to the "balance control".

--
John Phillips

In article , John Phillips
wrote:
In article , Jim Lesurf wrote:
Provided the 'swap' tests showed this stayed firmly in the same
'direction' so far as perception was concerned I assume your equipment
is fine. If the image is reasonably narrow and well defined, then it
is probably OK just to resign yourself to using the offset and getting
results that then sound fine! About all it then implies is that one
speaker might be being driven a bit harder than the other.

Well, I think I finally have it right (or close to) after all,

Excellent. :-)

Having moved a small book-case I noticed an improvement. I was prompted
to go back to adjusting the speakers' positions. Now I have the stereo
image well balanced with no artificial adjustment.

It looks (from an optical perspective) like the adjustments have got the
side-wall accoustic reflection environment more symmetrical. There is
now some damping of the accoustic reflection at the right points on both
side-walls, whereas previously there was damping on only one side and a
bare wall on the other. Maybe this was the cause of the imbalance. Some
guides (e.g. from Audio Physic) make much of side-wall reflections.

The above makes sense to me. Sidewall reflections can have a distinct
effect on the stereo image, so what you describe fits well with what I'd
expect.

Anyway, regardless of the exact issue, I guess it was the room after
all. It looks like I didn't spend long enough to position the speakers
earlier before resorting to the "balance control".

FWIW I find it pays dividends to spend a fair bit of time on speaker
placement, etc. During the first few days of using 'new' speakers in a room
I tend to move them (and other things) around lot. Then I tend to go
through a repeated process of leaving things for a while, then making some
small changes and giving them a time to see what I prefer. This tends to
involve longer and longer 'settling' periods between experiments, and
smaller and smaller movements. The result being that it can take months to
iterate down to what seems decent solution. But I do feel that doing this
can end up with a sound that is preferred to what was obtained after the
first week or two.

e.g. Having bought new speakers in the spring, a couple of weeks ago I
slightly altered the angling of the speakers, and after a few days decided
that it was slightly better in the new arrangement.

How much of this is imagination in my case, I don't know, but it is
harmless fun, and gives me an excuse to 'rediscover' old recordings. :-)

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

"Jim Lesurf" wrote in message
...

Big snip

e.g. Having bought new speakers in the spring, a couple of weeks ago I
slightly altered the angling of the speakers, and after a few days
decided
that it was slightly better in the new arrangement.

How much of this is imagination in my case, I don't know, but it is
harmless fun, and gives me an excuse to 'rediscover' old recordings. :-)

Slainte,

Jim

You could always do a DBT and find out, Jim :-)

Alan