[Andrew Haley]

Gary Eickmeier wrote:
"Andrew Haley" wrote in message
...

Well, hold on. Placing the speakers at exactly 1/4 of the room width
is going to maximally excite the second mode. Notching that out isn't
going to be so easy, especially if you want to be able to listen in
more than one position. Placing subwoofers in the corners is
efficient, but it also maximally excites *all* of the room modes.

I repeat to the OP: don't believe any simple solutions. I recommend
CARA http://www.cara.de which alows people to do some simulations.

I can only suggest to you that if the room is large enough for
realistic reproduction, and if the radiation pattern is not pure
omni, or mostly direct, but rather has a D/R ratio with negative
directivity, then most of these classical engineering "rules" go out
the window. There will be no serious comb filtering, no room mode
problem, no notches or bad peaks.

C'mon Gary, you must know this is nonsense. Below the transition
frequency, speakers are mostly ominidirectional anyway, and you
can't get away from room modes. We cannae change the laws of physics,
captain!

The reason is that if the direct field is not as strong as most are
used to, then it will not add and subtract in equal proportions to
the early reflected sound. This is the sea change that permits us to
position speakers for imaging, not for frequency response.

The CARA series looks interesting, but I'm not so sure it isn't just
another look at frequency response only, like most of them out
there.

Certainly not.

It is loaded with pink noise signals and - horrors - sine waves!

I have no idea what you are talking about.

Andrew.