leave the popcorn in the cupboard, I'm unwilling to engage in discussions with a grumpy old man who behaves in such a disrespectful and contemptuous manner.
Excuse me? You misquoted me and insisted I said something I didn't, and that makes me "disrespectful"? Really?
I disagreed with what you said, and pointed out both the extraction from context and the rhetorical misconduct. If you don't want to hear about that, don't do it.
Sorry, no, you just picked a fight, and did so inaccurately.
jj mentioned the pressure responsive Omni in the context of the sound wave interference pattern with peaks and nulls so I understood this as meaning that the Omni reading (i.e. room impulse response) will tell you what you hear.
Which it will, in context, meaning vs. a room that does not have said modes, which is the present context. Of course the modes need to be excited, etc. The point I made is that nodes in pressure are only 1/4 of the story in regard to the actual energy storage in the room. Remember that an Omni captures pressure, which is what your eardrums also capture, and pretty much all you capture at very low frequencies. A cardioid captures 1/2 pressure and 1/2 volume velocity in one given direction, which is why it's directional, and why a node found with a pressure microphone is not likely to be a node found with a cardioid. (all depending, of course, on which way the cardioid is pointed, too)
As frequencies get higher, HRTF's convert part of the velocity field into pressure in the ear canal, and of course in a directionally sensitive fashion. How much is literally what determines your HRTF's.
But the point remains, at low frequencies, under 100Hz or so, a pressure microphone captures the same stimulus as your ear does. We are staying strictly in the acoustic domain here, not entering that of perception. There is no need to introduce anything beyond physical acoustics at this point.
As has been pointed out, looking at only the dimensions will not tell you anything about what is going to happen in the room! If you don’t take positions of source and listener into account the exercise is pretty much useless.
Klaus
Well, actually, no. Storage in a room that does not show itself as pressure at one spot in a room may still have effects that you don't want, from rattling windows to uncomfortable secondary listening positions. Moving source and destination will move around the modal responses, but does little to address the
overall energy storage. (Of course position and frequency may change.) Of course, the "size" of the room varies with frequency because of the wall impedance, but that's a secondary issue, except around wall resonance frequencies.
Using a full capture of the soundfield at one point, all 4 variables, it is possible to estimate the energy storage in a room quite accurately, even if you happen to be in a pressure node or a velocity node. (velocity nodes are pressure peaks, and vice versa, almost exactly.) The point is simple, too much storage, especially of the specular sort, is a problem, and diffusing bass is an interesting proposition to say the least. (remember, wavelength is ~1130/f in feet)