[[email protected]]

With excellent amps etc. having become commodity items and inexpensive for
some time, little new or better can be expected for sound experience
quality from the hardware end of things. That battle has been won.

The next big step it seems to me is in the area this article discusses.
It reminds me of a project I have been watching evolve for some years:

http://www.ambiophonics.org/

With similar goals, here in part is another effort that is worth reading
in its entirety:

http://www.nytimes.com/2011/09/06/sc...ml?ref=science

Acousticians have been designing concert halls for more than a century,
but Dr. Kyriakakis does something different. He shapes the sound of
music to conform to the space in which it is played. The goal is what
Dr. Kyriakakis calls the "ground truth" -- to replicate the original in
every respect. "We remove the room," he said, "so the ground truth can
be delivered."

Dr. Kyriakakis, an electrical engineer at U.S.C. and the founder and
chief technical officer of Audyssey Laboratories, a Los Angeles-based
audio firm, could not achieve his results without modern sound filters
and digital microprocessors.

But the basis of his technique is rooted in the science of
psychoacoustics, the study of sound perception by the human auditory
system. "It's about the human ear and the human brain, and
understanding how the human ear perceives sound," Dr. Kyriakakis said.

[Arny Krueger[_4_]]

wrote in message
...

With excellent amps etc. having become commodity items and inexpensive for
some time, little new or better can be expected for sound experience
quality from the hardware end of things. That battle has been won.

The next big step it seems to me is in the area this article discusses.
It reminds me of a project I have been watching evolve for some years:

http://www.ambiophonics.org/

With similar goals, here in part is another effort that is worth reading
in its entirety:

http://www.nytimes.com/2011/09/06/sc...ml?ref=science

Acousticians have been designing concert halls for more than a century,
but Dr. Kyriakakis does something different. He shapes the sound of
music to conform to the space in which it is played. The goal is what
Dr. Kyriakakis calls the "ground truth" -- to replicate the original in
every respect. "We remove the room," he said, "so the ground truth can
be delivered."

Dr. Kyriakakis, an electrical engineer at U.S.C. and the founder and
chief technical officer of Audyssey Laboratories, a Los Angeles-based
audio firm, could not achieve his results without modern sound filters
and digital microprocessors.

But the basis of his technique is rooted in the science of
psychoacoustics, the study of sound perception by the human auditory
system. "It's about the human ear and the human brain, and
understanding how the human ear perceives sound," Dr. Kyriakakis said.


The Audyssey system is a self-adjusting equalizer that is commonly
incorporated into mid-fi and higher end receivers.

Example:

http://www.amazon.com/Denon-AVR2112C...5325640&sr=8-1

[Audio Empire]

On Tue, 6 Sep 2011 08:40:34 -0700, wrote
(in article ):

With excellent amps etc. having become commodity items and inexpensive for
some time, little new or better can be expected for sound experience
quality from the hardware end of things. That battle has been won.

Actually, the battle is for speakers and room acoustics control. We're a long
way for getting those right. Agreed that amps, even though there are still
small sonic differences, are mostly all pretty neutral these days.

The next big step it seems to me is in the area this article discusses.
It reminds me of a project I have been watching evolve for some years:

http://www.ambiophonics.org/

With similar goals, here in part is another effort that is worth reading
in its entirety:

http://www.nytimes.com/2011/09/06/sc...ml?ref=science

Until we can control room acoustics, any kind of musically accurate surround
sound scheme is a pipe dream. Sure, for home theater, surround can be
thrilling, but for musical presentation, we need to get two-channel as
affordably close to perfect as we can before treading those waters.

Acousticians have been designing concert halls for more than a century,
but Dr. Kyriakakis does something different. He shapes the sound of
music to conform to the space in which it is played. The goal is what
Dr. Kyriakakis calls the "ground truth" -- to replicate the original in
every respect. "We remove the room," he said, "so the ground truth can
be delivered."

This could have some promise (if it works). But I've heard true Ambisonic
demonstrations and have never been impressed. This would have to be much
better than that.

Dr. Kyriakakis, an electrical engineer at U.S.C. and the founder and
chief technical officer of Audyssey Laboratories, a Los Angeles-based
audio firm, could not achieve his results without modern sound filters
and digital microprocessors.

But the basis of his technique is rooted in the science of
psychoacoustics, the study of sound perception by the human auditory
system. "It's about the human ear and the human brain, and
understanding how the human ear perceives sound," Dr. Kyriakakis said.

[Gary Eickmeier]

This is almost pure Image Model Theory as stated in my paper from 1989,
which I have bandied about in these halls many times before, and which I
would be glad to send to anyone interested. I believe Audio Empire has a
copy.

IMT is basically the reconstruction of all important sound fields within the
listening room. I advocate a large room, of rectangular shape, and not
killing all reflections but using them to model the playback after a good,
typical concert hall. We don't want to ADD extra sounds to what was
recorded, just SHAPE the playback to place all important sounds where they
belong.

This guy is going further than most of us can do with available commercial
consumer equipment, but you can have the 90% solution with a good surround
sound system placed correctly in a good, large room.

If this guy is working with Tom Holman he is well grounded and not a crank.
I am saying that I basically agree with his approach and adding that it
helps reinforce the need for an over-arching new stereo theory that explains
better what he is doing in shaping the sound fields in the listening room by
mimicking live sound fields. I called it image modeling, and my paper is
called An Image Model Theory for Stereophonic Sound, but I haven't got
thousands of dollars and a laboratory to demonstrate it in. I hope this
succeeds. "Two ears/ two speakers" stereo has got to be laid to rest.

Gary Eickmeier

[Gary Eickmeier]

"Arny Krueger" wrote in message
...

The Audyssey system is a self-adjusting equalizer that is commonly
incorporated into mid-fi and higher end receivers.

Example:

http://www.amazon.com/Denon-AVR2112C...5325640&sr=8-1


Hi Arn -

Thanks for the reference. Perhaps I stand corrected when I said that what he
is doing is not possible with commercially available equipment! Looks like a
very sophisticated unit, and not a bad price. What I am wondering about is
the sentence

"Audyssey MultEQ XT measures sound levels and adjusts speaker configuration
accordingly, making setup fast and easy."

Surely this thing can't tell you what speakers to buy, with what radiation
pattern, and where to place them - much less how to select and treat your
room! It must just be a program to set delays and EQ as best it can with the
configuration presented to it, IAW their model for good acoustics. Perhaps
their instruction manual tells the user where to place speakers, and how
many to use, etc etc. I think I will write to him and ask a few questions.
Probably can download the manual for the receiver. Anyone done this yet?

Gary Eickmeier

[Audio Empire]

On Wed, 7 Sep 2011 10:20:06 -0700, Gary Eickmeier wrote
(in article ):

"Arny Krueger" wrote in message
...

The Audyssey system is a self-adjusting equalizer that is commonly
incorporated into mid-fi and higher end receivers.

Example:

http://www.amazon.com/Denon-AVR2112C...iver/dp/B004Z0
S7OM/ref=sr_1_1?ie=UTF8&qid=1315325640&sr=8-1


Hi Arn -

Thanks for the reference. Perhaps I stand corrected when I said that what he
is doing is not possible with commercially available equipment! Looks like a
very sophisticated unit, and not a bad price. What I am wondering about is
the sentence

"Audyssey MultEQ XT measures sound levels and adjusts speaker configuration
accordingly, making setup fast and easy."

Surely this thing can't tell you what speakers to buy, with what radiation
pattern, and where to place them - much less how to select and treat your
room! It must just be a program to set delays and EQ as best it can with the
configuration presented to it, IAW their model for good acoustics. Perhaps
their instruction manual tells the user where to place speakers, and how
many to use, etc etc. I think I will write to him and ask a few questions.
Probably can download the manual for the receiver. Anyone done this yet?

Gary Eickmeier



What it does is measure the in-room response of your speakers at your
listening position, and then it "dials-out" the effects of the room on the
sound field by EQ-ing the speakers (actually it EQs the amplifier as the
speakers are passive) to compensate for room anomalies in frequency response.
There's nothing new in this except the methodology. In the old days, you'd
buy a 1/3-octave active equalizer and hire a technician with an audio
spectrum analyzer to come in and adjust the equalizer to give flat frequency
response at your listening position. He would then fasten a guard plate over
the equalizer controls and leave. If you kept your grubbies off the controls,
and didn't move large pieces of furniture around the room, your system stayed
flat. The downside was, of course, that 1/3-octave active equalizers were
notoriously colored. Filters ring and have an insertion loss.They always
muddied-up the sound somewhat.

The difference with the Audyssey and other such systems is that now, instead
of a "guy", the computer does this digitally. The filtering itself is done in
the digital mode with DSP technology and, ostensibly, digital filters can be
designed so that they don't ring or have the out-of-band phase anomalies that
plagued analog equalizers.

[Gary Eickmeier]

"Gary Eickmeier" wrote in message
...
This is almost pure Image Model Theory as stated in my paper from 1989,
which I have bandied about in these halls many times before, and which I
would be glad to send to anyone interested. I believe Audio Empire has a
copy.

IMT is basically the reconstruction of all important sound fields within
the
listening room. I advocate a large room, of rectangular shape, and not
killing all reflections but using them to model the playback after a good,
typical concert hall. We don't want to ADD extra sounds to what was
recorded, just SHAPE the playback to place all important sounds where they
belong.

This guy is going further than most of us can do with available commercial
consumer equipment, but you can have the 90% solution with a good surround
sound system placed correctly in a good, large room.

If this guy is working with Tom Holman he is well grounded and not a
crank.
I am saying that I basically agree with his approach and adding that it
helps reinforce the need for an over-arching new stereo theory that
explains
better what he is doing in shaping the sound fields in the listening room
by
mimicking live sound fields. I called it image modeling, and my paper is
called An Image Model Theory for Stereophonic Sound, but I haven't got
thousands of dollars and a laboratory to demonstrate it in. I hope this
succeeds. "Two ears/ two speakers" stereo has got to be laid to rest.

Gary Eickmeier

Well, I just perused the web site of this Audyssey company and it was a
little disappointing. Look at
http://www.audyssey.com/audio-technology/multeq/tour and see that all they
are doing is varying levels of EQ and time domain room correction. I think I
have read about them a few times before.

In my opinion, it is misguided to try for a flat response at the listening
position, and it is a mistake to assume that all reflections are evil and
try and "correct" for them with time domain filtering. So this is not IMT,
and they are not giving great guidance in selecting and positioning speakers
and doing room treatment and generally setting up a realistic soundfield in
your room.

They are just selling stuff.

Gary Eickmeier

[Scott[_6_]]

On Sep 6, 8:40=A0am, wrote:
With excellent amps etc. having become commodity items and inexpensive fo=
r
some time, little new or better can be expected for sound experience
quality from the hardware end of things. =A0That battle has been won.

The next big step it seems to me is in the area this article discusses. =
=A0
It reminds me of a project I have been watching evolve for some years:

http://www.ambiophonics.org/

With similar goals, here in part is another effort that is worth reading
in its entirety:

http://www.nytimes.com/2011/09/06/sc...?ref=3Dscience

The author of the article really steps in it here.
"But stereo had no real psychoacoustics. It created an artificial
sense of space with a second track, but did so by dealing with only
one variable =97 loudness =97 and enhanced human perception simply by
suggesting that listeners separate their speakers."

Seriously? Stereo had no real psychoacoustics? Credibility goes right
out the door then and there.


Acousticians have been designing concert halls for more than a century,
but Dr. Kyriakakis does something different. He shapes the sound of
music to conform to the space in which it is played. The goal is what
Dr. Kyriakakis calls the "ground truth" -- to replicate the original in
every respect. "We remove the room," he said, "so the ground truth can
be delivered."

removing the room (the listening room) is IMO a good idea. Of course
one does not do that by bouncing the sound off the walls.



Dr. Kyriakakis, an electrical engineer at U.S.C. and the founder and
chief technical officer of Audyssey Laboratories, a Los Angeles-based
audio firm, could not achieve his results without modern sound filters
and digital microprocessors.

But the basis of his technique is rooted in the science of
psychoacoustics, the study of sound perception by the human auditory
system. "It's about the human ear and the human brain, and
understanding how the human ear perceives sound," Dr. Kyriakakis said.

Sloppy article. No surprise there. Wonder if his research has taken
into account the vast array of stereo recordings and stereo recording
techniques out there. Trying to mimic a specific concert hall using
their one recording made in that concert hall strikes me as a pretty
narrow approach. But who knows? The article seems to be full of
questionable reporting.

[---MIKE---]

I have a Rane 1/3 octave equalizer and a Rane spectrum analyzer. I
tried eq-ing the room by setting the equalizer for a flat response at
the listening position. It sounded awful! Now I have the equalizer
adjusted by ear and it sounds good. Maybe this is because my speakers
(DBX Soundfield Ones) bounce a lot of sound off the walls.

[Arny Krueger[_4_]]

"---MIKE---" wrote in message
...
I have a Rane 1/3 octave equalizer and a Rane spectrum analyzer. I
tried eq-ing the room by setting the equalizer for a flat response at
the listening position. It sounded awful! Now I have the equalizer
adjusted by ear and it sounds good. Maybe this is because my speakers
(DBX Soundfield Ones) bounce a lot of sound off the walls.


Possibly.

Nobody who knows what they are doing adjusts speaker systems for measured
flat response at the listening location in every case. They always use some
kind of "room curve", IOW a thought-out deviation from flat response.

Current thinking about room curves is not perfectly consistent. A general
trend seems to be that the room curve rolls off the high frequency response
above some frequency in the 3-8 KHz range, often a lower frequency for a
larger room.

There is a question in some people's minds about whether or not a typical HT
room even requires a room curve because it is relatively small. OTOH,
non-flat room curves are used to tune audio systems for cars, and a
passenger compartment is a pretty small, dead room.

I think that there is a belief that the roll off frequency drops as more
reflections are heard at the listening location, which may relate to your
personal experience.

[Arny Krueger[_4_]]

"Gary Eickmeier" wrote in message
...

Well, I just perused the web site of this Audyssey company and it was a
little disappointing. Look at
http://www.audyssey.com/audio-technology/multeq/tour and see that all
they
are doing is varying levels of EQ and time domain room correction. I think
I
have read about them a few times before.

One can find quite a bit of discussion about Audyssey on many HTML-based
home theater forums.

It does seem to get a fair amount of favorable comment from many end-users
and some reviewers based on personal experience. If it turned receivers into
boat anchors, it wouldn't show up in as much equipment as it does.

In my opinion, it is misguided to try for a flat response at the listening
position, and it is a mistake to assume that all reflections are evil and
try and "correct" for them with time domain filtering.

On the isssue of room reflections, our mutual friend David Clark seems to
think that the ear is pretty efficient at negating the effects of
reflections in the room that you are listening in. He seems to like the word
"dereverberation". Something like it seems to be in play, within reasonable
limits.

They are just selling stuff.

I think so. The cited materal seems to have a lot of fancy words, and create
an impression that the Audyssey process is more sophisticated than many
well-informed audiophiles and industry experts actually think it is.

[Ed Seedhouse[_2_]]

On Sep 8, 6:34=A0am, "Arny Krueger" wrote:
"Gary Eickmeier" wrote in message

On the isssue of room reflections, our mutual friend David Clark seems to
think that the ear is pretty efficient at negating the effects of
reflections in the room that you are listening in. He seems to like the w=
ord
"dereverberation". Something like it seems to be in play, within reasonab=
le
limits.

There may be something to this - back in the 1960's when we were all
young and foolish I tried LSD a few times and one of the first
symptoms of it taking it's effects were always, for me, that I
suddenly started noticing room reflections I normally didn't hear. So
maybe the drug was knocking out those brain circuits that the brain
uses in suppressing room reflections as suggested above. Of course
this is merely anecdotal, and not evidence, but I thought I would
mention it for what it's worth.

I think so. The cited materal seems to have a lot of fancy words, and cre=
ate
an impression that the Audyssey process is more sophisticated than many
well-informed audiophiles and industry experts actually think it is.

I have an Onkyo receiver that includes the basic version it and I
think it's main effect is not so much on frequency response but on
adjusting the time delay for sloppily placed speakers so that the
sounds they make arrive at the ears together in spite of the miss-
adjustment. They also seem to improve the midrange of my front
speakers slightly and I prefer the sound with the Audyssey processing
on.

However, after running the adjustment program I have to dash over to
the sub and turn it down because the thing makes the bass far too
prominent for my tastes.

Once again, of course, merely subjective impressions that shouldn't be
taken too seriously.

[Audio Empire]

On Wed, 7 Sep 2011 16:48:43 -0700, Scott wrote
(in article ):

On Sep 6, 8:40=A0am, wrote:
With excellent amps etc. having become commodity items and inexpensive fo=
r
some time, little new or better can be expected for sound experience
quality from the hardware end of things. =A0That battle has been won.

The next big step it seems to me is in the area this article discusses. =
=A0
It reminds me of a project I have been watching evolve for some years:

http://www.ambiophonics.org/

With similar goals, here in part is another effort that is worth reading
in its entirety:

http://www.nytimes.com/2011/09/06/sc...?ref=3Dscience

The author of the article really steps in it here.
"But stereo had no real psychoacoustics. It created an artificial
sense of space with a second track, but did so by dealing with only
one variable =97 loudness =97 and enhanced human perception simply by
suggesting that listeners separate their speakers."

Seriously? Stereo had no real psychoacoustics? Credibility goes right
out the door then and there.


Acousticians have been designing concert halls for more than a century,
but Dr. Kyriakakis does something different. He shapes the sound of
music to conform to the space in which it is played. The goal is what
Dr. Kyriakakis calls the "ground truth" -- to replicate the original in
every respect. "We remove the room," he said, "so the ground truth can
be delivered."

removing the room (the listening room) is IMO a good idea. Of course
one does not do that by bouncing the sound off the walls.

Yeah, it looks good on paper. Remove the listening venue from the equation
and replace it with the performance venue's acoustic signature - along with
the performance. Easier said than done, unfortunately. Even DSP-based room
correction schemes are only partially successful because EQ-ing a system to
alter it's frequency domain in order to overcome peaks and valleys in
response caused by room interaction seems to me to only be addressing
first-order effects - amplitude anomalies. I don't believe that any of these
schemes address time-related anomalies at all and I don't see how any such
system can address room size (with regard to wavelength, anyway).



Dr. Kyriakakis, an electrical engineer at U.S.C. and the founder and
chief technical officer of Audyssey Laboratories, a Los Angeles-based
audio firm, could not achieve his results without modern sound filters
and digital microprocessors.

But the basis of his technique is rooted in the science of
psychoacoustics, the study of sound perception by the human auditory
system. "It's about the human ear and the human brain, and
understanding how the human ear perceives sound," Dr. Kyriakakis said.

Sloppy article. No surprise there. Wonder if his research has taken
into account the vast array of stereo recordings and stereo recording
techniques out there. Trying to mimic a specific concert hall using
their one recording made in that concert hall strikes me as a pretty
narrow approach. But who knows? The article seems to be full of
questionable reporting.

Seems to me that in order for this approach to work, the world would have to
come to a consensus about what constitutes a proper stereo recording. And,
that, my friends, will never happen. I can tell you from long experience,
that there are about as many opinions on THAT subject as there are recording
engineers and producers (and in my not-so-humble-opinion, any stereo
recording scheme that starts with more than two microphones for the
performers is suspect 8^).

[Audio Empire]

On Wed, 7 Sep 2011 18:39:11 -0700, MIKE--- wrote
(in article ):

I have a Rane 1/3 octave equalizer and a Rane spectrum analyzer. I
tried eq-ing the room by setting the equalizer for a flat response at
the listening position. It sounded awful! Now I have the equalizer
adjusted by ear and it sounds good. Maybe this is because my speakers
(DBX Soundfield Ones) bounce a lot of sound off the walls.


That can happen. I had a friend (now deceased) who paid a lot of money (in
the 1970's) for a Crown 1/3-octave equalizer and a tech with a spectrum
analyzer to come in and EQ his system in his listening room. He had a pair of
Altec Lansing 15-inch woofers mounted in bass-reflex cabinets designed by
Altec (but built by a local cabinet-maker) and topped with an Altec 500 Hz
treble horn. The system started out sounding lousy (the Altec trebel horn was
always a terrible transducer in my estimation) and after the EQ, it sounded
even worse. I think the reason was because EQ couldn't overcome some of the
Altec system's basic flaws, not all of which could be EQ-ed out. That might
be your problem, I don't know.

For my own part, I now run a new HK 990 Integrated amp. (dual mono design,
150 Watts/channel, built-in room correction software, built-in dual
differential 24/192 DACs, built-in phono preamps, built-in ADC (for digital
recording from analog sources), etc). I have used the EQ setup for my room
and with my Martin Logan electrostatics with subwoofers, the EQ scheme
smoothed out the transition from the Martin-Logans to the subs in such a way
that they are now seamless (can't tell where the crossover point is and I
can't hear the subs as a separate entity. Turn 'em off, and the low bass
simply goes away. The character of the bass doesn't change at all!). I find
that the EQ seems to do very little (you can defeat the effect and bypass the
EQ with a flick of the remote control) with the response of the system
otherwise. Yeah, you can hear a difference on a direct A/B, but it's not
profound. I keep it in the system because the EQ Software did what I was
never able to accomplish by ear **getting my subwoofers to integrate properly
with the main speaker system.

[Gary Eickmeier]

"Arny Krueger" wrote in message
...

On the isssue of room reflections, our mutual friend David Clark seems to
think that the ear is pretty efficient at negating the effects of
reflections in the room that you are listening in. He seems to like the
word
"dereverberation". Something like it seems to be in play, within
reasonable
limits.

Dr. Mark Davis wrote pretty much the complete story on what is happening
with this in an article in Stereo Review:

"AUDIO SPECIFICATIONS AND HUMAN HEARING



By Mark F. Davis



Stereo Review

May 1982 p52





Hearing in Space



...



Distance judgements seem to depend on an even more complicated evaluation
involving relative amplitudes and the reverberation content of sounds.



All this "processing" is carried out simultaneously on all the direct sounds
and echoes that impinge on the ears, even if you're at the Super Bowl
surrounded by 50,000 screaming sound sources. The result is that you can
concentrate on what the person next to you is saying and filter out most
sounds (they may even be louder ones) coming from other directions. This
ability has been aptly named the "cocktail party effect."



Moreover, the cocktail-party effect operates over the previous 50
milliseconds of audio, the contents of the brain's 50-millisecond audio
memory are apparently tagged with their estimated source positions, allowing
the brain to ignore spatial information it has recently determined to be
extraneous. In particular, this process permits the suppression of spatially
divergent echoes from the consciousness. In order to be suppressed, an echo
must:



1.. arrive within 50 milliseconds of the primary-source signal, and


2.. come from a different direction than the source signal - otherwise the
brain assumes the echo was emitted by the source and you hear a change in
the sound of the source (this is one reason why speaker sound can be greatly
influenced by speaker placement in a room).


Most echoes die out within 50 milliseconds in the average room, and they are
usually spatially diverse. This allows them to be perceptually suppressed.
The monaural recording you made of your friend speaking inhibited the action
of your brain's echo-suppression system by by doing away with the clues it
needed to identify and ignore echoes. In a large enclosed area where the
time lags are much longer than 50 milliseconds (churches, concert halls,
auditoriums), the 50 millisecond memory capacity is exceeded, and even
spatially divergent echoes can become audible."



Gary Eickmeier

[Harry Lavo]

"Arny Krueger" wrote in message
...
"Gary Eickmeier" wrote in message
...

Well, I just perused the web site of this Audyssey company and it was a
little disappointing. Look at
http://www.audyssey.com/audio-technology/multeq/tour and see that all
they
are doing is varying levels of EQ and time domain room correction. I
think
I
have read about them a few times before.

One can find quite a bit of discussion about Audyssey on many HTML-based
home theater forums.

It does seem to get a fair amount of favorable comment from many end-users
and some reviewers based on personal experience. If it turned receivers
into
boat anchors, it wouldn't show up in as much equipment as it does.

In my opinion, it is misguided to try for a flat response at the
listening
position, and it is a mistake to assume that all reflections are evil and
try and "correct" for them with time domain filtering.

On the isssue of room reflections, our mutual friend David Clark seems to
think that the ear is pretty efficient at negating the effects of
reflections in the room that you are listening in. He seems to like the
word
"dereverberation". Something like it seems to be in play, within
reasonable
limits.

They are just selling stuff.

I think so. The cited materal seems to have a lot of fancy words, and
create
an impression that the Audyssey process is more sophisticated than many
well-informed audiophiles and industry experts actually think it is.


It is interesting to note that Kal Rubenstein who does the surround column
for Stereophile always seems to have to "tweak" the Audyssey settings
derived automatically. He claims it gets you in the ballpark, but that the
ear is ultimately the better judge of what sounds correct.

[Arny Krueger[_4_]]

"Harry Lavo" wrote in message
...

It is interesting to note that Kal Rubenstein who does the surround column
for Stereophile always seems to have to "tweak" the Audyssey settings
derived automatically. He claims it gets you in the ballpark, but that
the
ear is ultimately the better judge of what sounds correct.

For relatively large differences, such as those involved with obtaining a
good sounding system in a listening room, the ear is indeed the better
judge. Technical tools are great for getting system response into the "basll
park" which is in itself quite interesting. I appears that the ear works
best when the sound quality is already quite good. IOW it is a better tool
for tweaking than making large changes.

There are far more sophisticated tools for measuring system response, such
as the DLC Perceptual Transfer Function measurement set:

http://www.aes.org/e-lib/browse.cfm?elib=9248

http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf