Is there any rule of thumb...

[cobbpa]

As to, say, a room of X cubic feet should have speakers able to displace Y% air of X to be reasonably loud / listenable? Talking about non-sub frequencies here. I know efficiency comes into play, as does whether or not the woofers are being pushed to their limits, along with what frequencies we're talking about...but usually rules of thumb don't include this much detail. Basically looking for a starting point in a speaker search.

[Rudy Jakubin]

I think this might be it;

http://home.mn.rr.com/hometheater/acoustics.htm

[cobbpa]

Interesting stuff..thanks for the link!
Can anyone work out the Excel formulas for the low frequency excursion & power needed? I don't know if I'm missing something or what but I can't figure out how to get his numbers..

[ThomasW]

http://www.linkwitzlab.com/spl_max1.xls