Is it better to have a rectangular room or one with non-parallel walls?

[syswei]

I am going to build an HT room, of perhaps 2500-3500 cu ft, in my basement. I don't really understand whether I'd be better off, from an acoustic standpoint, with a (a) rectangular room, or with (b) non-parallel walls. In an earlier thread someone said that non-parallel walls would still have standing waves, but it would be more complex. OK, but better or worse, overall? What would you do if building a dedicated room?

BTW I do plan on some room eq, Behringer DEQ2496, Audyssey, Lexicon MC-12, Meridian G68, or Anthem D2 (due to get it in a few months)...yes I do realize that these are at very different price points, and that the latter 3 don't do the full frequency range.

 

[mike c]

while non-parallel walls are good, nobody can predict what will happen to the sound waves ... (unless you build to exact dimensions including degree of non-parallel walls)

so you might be better off trying the golden room ratios where the sound waves are more predictable:

1 1.14 1.39
1 1.28 1.54
1 1.6 2.33

 

[mtrycrafts]

I am going to build an HT room, of perhaps 2500-3500 cu ft, in my basement. I don't really understand whether I'd be better off, from an acoustic standpoint, with a (a) rectangular room, or with (b) non-parallel walls. In an earlier thread someone said that non-parallel walls would still have standing waves, but it would be more complex. OK, but better or worse, overall? What would you do if building a dedicated room?

BTW I do plan on some room eq, Behringer DEQ2496, Audyssey, Lexicon MC-12, Meridian G68, or Anthem D2 (due to get it in a few months)...yes I do realize that these are at very different price points, and that the latter 3 don't do the full frequency range.

It is really hard to say. Room acoustics is a rather complex issue.
But, I can suggest that you also add the Behringer feedback destroyer, 2-12 band EQ in the digital domain that can be assigned most any audio band frequency to correct at most any shape( wide to very narrow in a very wide range) and, if need be, you can daisy chain the two channels if you need 24 frequency adjustments. A bit to get the hand of it but once you have it, it is easy.

 

[Savant]

The thing about non-rectangular rooms and prediction is not that it cannot be done; it's that it's very difficult to do. (I.e., no easy online calculators are available.)

Non-parallel walls can work well if they're properly designed, but can also be a detriment if they're not well thought out. For example, just angling one wall at 10° is not likely to give you better results and will mess up the symmetry of the room, even though some problems (relative to a rectangular room) might be eliminated.

For a home theater room with the volume range you're considering, my advice would be to keep it rectangular and maximum space. While you could utilize angles to minimize acoustical problems such as flutter, the effort required to design and build in the angles is, in general (and in my experience), not offset by the acoustical advantages. You're still going to need more or less the same amount of acoustical treatments in the room.

HTH.

 

[bpape]

I'd agree with Jeff 100%. Splayed walls can be a good thing if done right, symmetry kept in mind, and you have the space to do it right without crowding speakers/screen/walls. In most cases, you'll be better off with the additional room volume.

Bryan