Do you need different room proportions for a desirable 2 channel vs. 5.1/7.1 setup?

[Chris A]

I have noticed that many 2-channel enthusiasts like to use the wide dimension of the room as the front (ref., PWK's 3-channel configuration with corner Khorns and a center Belle/La Scala/Cornwall/Heresy), while most 5.1/7.1 setups characteristically use the short wall for the front, using the surround speakers abreast or behind the listening positions to reinforce ambience and to keep the listening positions away from being too close to the walls. This would indicate that there are probably different opinions over the relative dimensions (length x width x height) of an ideal room between primarily 2-channel and 5.1/7.1 applications.

For instance, consider an example room with relative dimensions: 1.6 x 2.6 x 1 to avoid dealing with potentially nasty room modes piling up on one another. Room modes play havoc with the size, number and placement of subwoofers, the placement of good listening positions, and with in-room EQ of mid-bass frequencies.

The minimum desirable physical room dimension is probably something greater than 9 feet (~2.7 m, usually height...but not always) ) because of precedence effects and room reflections (unless you made the room into an anechoic chamber, which isn't very desirable IMHO). This would give us a minimum-sized room of 14.4 x 23.4 x 9 feet (4.4 x 7.1 x 2.7 m).

Would you 2-channel guys still try to use the long dimension as the front wall in this example?

Does anyone believe that it is better to use a room's wide dimension as the front in their HTs?

Chris

[artto]

It’s an interesting dilemma that I’m sure even a lot of us
old timers are encountering, including myself.

I guess it depends on what your priorities are, and what
kind of seating capacity/arrangement is required by you.

With HT I like the idea of having more space behind me
simply because of the 5-7 channel thing, so using the short wall as the “front”
may be preferable. But it will certainly “shrink the stage” for musical
performance.

I my case, I have no intention of using the room as a home
theater with more than me, my wife and our dog, and maybe one or two more
people, pretty much the same as with music, so the main speakers will most
likely stay on the long wall. If your needs require a larger HT audience from
time to time, then you might prefer the main speakers on the shorter wall so
more people have the proper “view”, along with the rear speakers not being
immediately behind their ears.

And don’t forget, the recommendation that the speakers be
placed on the long wall, emanates from the typical size and proportions encountered
in most residences. On the other hand, if the room is quite large, say 30’x40’,
the short wall will probably be very adequate for the mains. You can have your
cake and eat it too. I really boils down to how much real estate can you
afford.