[avaserfi]

Ethan Winer wrote:

Same advice. If you think about it, when the off-axis response is the same as on-axis, that makes the resultant comb filtering even more damaging because all frequencies are reinforced and canceled maximally. Assuming perfect reflectivity of course.

You are right there would be comb filtering created as a side effect of this methodology, but in Floyd Toole's research it was shown that despite this comb filtering the slightly delayed reflections were still found to be more enjoyable than use of an unreflective surface. All relevant articles are cited below.

Ethan Winer wrote:

My research shows exactly the opposite.

What kind of research is this? How was it done? Do you by any chance have the publication listing so I can read it?

Ethan Winer wrote:

It might be that in a very large room - and I'm talking 20 feet wide or wider - that side-wall reflections are less damaging than in a more typical size room. But generally speaking, small-room reflections are always best avoided IMO. Especially if the reflecting surfaces are closer than ten feet to your ears. BTW, this includes the rear wall behind you too.

While a large room would be beneficial in reduction of comb filtering as previously mentioned the preference still lay with a reverberant surface in place.

Kal Rubinson wrote:

Enjoyment is highly subjective and multivariate. Can you offer a link to such research?

You would actually be surprised how many facets of speaker design have been solidified as ideal and non-ideal. While certain tendencies lay with preference credible research has shown that most do not. Some of these are obvious such a smooth on axis frequency response and the ability to dynamically produce lower frequencies. Some others include a lack of all audible resonance, off-axis response similar, if not matching, the axial response, a gradual roll off of the treble to match how the human ear works (this one in part lies with preference as some people prefer a larger roll off than others).

There are various papers on these subjects. Floyd Toole has many regarding relating measurements to listener preference as well as room interaction.

Some notable articles of his include (I will not be able to link these as they aren't posted online your local library would be your best bet):

Listening Tests-Turning Opinion into Fact JAES Volume 30 Issue 6 pp. 431-445; June 1982

Subjective Measurements of Loudspeaker Sound Quality and Listener Performance JAES Volume 33 Issue 1/2 pp. 2-32; February 1985

Loudspeaker Measurements and Their Relationship to Listener Preferences: Part 1 JAES Volume 34 Issue 4 pp. 227-235; April 1986

Loudspeaker Measurements and Their Relationship to Listener Preferences: Part 2 JAES Volume 34 Issue 5 pp. 323-348; May 1986

The Modification of Timbre by Resonances: Perception and Measurement JAES Volume 36 Issue 3 pp. 122-142; March 1988

The Detection of Reflections in Typical Rooms JAES Volume 37 Issue 7/8 pp. 539-553; July 1989

Loudspeakers and Rooms for Sound Reproduction—A Scientific Review JAES Volume 54 Issue 6 pp. 451-476; June 2006

Well it looks like I have listed all of his articles. I guess this is because simply put he is the leading researcher involved with perception in relation to loud speakers. Also, if you look up Ian Paisley's research you will see that through thousands of blinded trials with thousands participants, that wider and smoother frequency responses were highly preferred in a controlled environment.