are there any rules of thumb for determining the appropriate number of
subwoofers for a given room size? Or is location more important than
quantity?

I've read Todd Welti's white paper for Harmon, which seems to suggest a
case of diminishing returns for anything more than 4 subwoofers...or
maybe that's 4 subwoofer *locations* ?

Eg., would you need more subs for adequate SPL & coverage in a room
that's 16' x 27' x 12' than you would for a room that's 8' x 12' x
7.5', or is it just a matter of turning up the subwoofer gain in the
larger room?


Thanks.

There is not only rules of thumb,but calculations if your really keen!
For a start you can keen it simple and consider
Sensitivity,Power(RMS),and SPL required at 1metre,this ignores the room
at the moment. For more calculations there a paper at jblpro.com

Location is just as important! A corner location for a subwoofer
results in a higher SPL but room modes are excited
maximally(theoretically)

The theory is that having more subwoofers , located in the room at the
right positions results in a more flatter frequency response since each
unit exites the room resonances with less energy(if I remember
correctly)

Note that one subwoofer is hard enough to set up - let alone 4. I would
get one,set that one up correctly,and then if im feeling rich get
another. Distortion will be reduced aswell by buying 2 units and
keeping SPL the same.

Generalised sweeping statement :
In regular sized rooms, with typical amplifiers available,and with
typical listening preferences a 10" or 12" of a litre or so
displacement typically is enough.

Regards
Mike.e

Toxicbass wrote:

Generalised sweeping statement :
In regular sized rooms, with typical amplifiers available,and with
typical listening preferences a 10" or 12" of a litre or so
displacement typically is enough.

And if it's not just add more drivers. Also check out
http://f20.parsimony.net/forum36475/ also known as the cult of the
infinitely baffled.