For HT, how important is extension south of 20 Hz?

Good question and I don't know the answer. I've never measured the low freq output in any movie I've watched so I'm not sure how low they go?

I'd guess that the lower the sub will go...the less problems it may have out putting the freq's above at high SPL's?

My room is 4600 cubic ft.... 3 VMPS subs (17hz)...each has an active 15" and 12" driver, and a 15" passive,...nearly bone crushing bite when called for, extended low freq harmonics in SiFi and Horror type movies are amazing in their ability to pressurize the room.

That said...what freq's are these? I'm not sure.

Dave

02-19-07: Drubin
"And then there is legendary Brown Note, the frequency reportedly somewhere between 5Hz and 20Hz that invokes involuntary gastrointestinal motility. Wouldn't want to miss out on that. Great for parties and family gatherings"

HeHe....they busted that one on the Myth Busters TV show.

Dave