Multiple Small Subs - Geddes Approach

[AllenB]

Excuse me if this has been asked, but using three bandpass subs in a typical living room and seeking maybe just less than live levels, can this normally be done with, say, three 8" drivers? smaller?

[gedlee]

Tough with 8" and certainly not possible with smaller. But then again what does "just less than live levels" mean? I use 12", I could make 10" work, but 8" is pushing things quite a bit.

[454Casull]

Just a bump to get this back near the top. This is too good a thread to let it die.

EDIT: By the way, I'm nitpicking here, but this page:

http://mehlau.net/audio/multisub_geddes/

says

Because we are using 3 subwoofers, they do not need to be as powerful as a single subwoofer. Any decent active subwoofer (ported or closed design) with a 10" or bigger driver will do. It should have controls for
level (infinitely variable)
low pass frequency (infinitely variable)
phase (switchable or infinitely variable)

It makes more sense to say continuously variable rather than infinitely variable as infinitely variable declares an infinite range, which of course cannot be the case.

[gedlee]

Nitpicky, yes, but also quite correct. Markus would have made the same comment!!

[markus76]

Changed it to "continuously"

Best, Markus

[AllenB]

Is there a story behind that 50Hz peak that you'd like to share?

[markus76]

Originally Posted by AllenB

Is there a story behind that 50Hz peak that you'd like to share?

Just a rather boring story - it's a typical peak caused by modes. When adding a subwoofer at a tri-corner, those peaks get boosted but the second sub "neutralizes" the peak. Looks like multiple subs work

[gedlee]

Markus! Welcome back. Living back in the EU again?

[markus76]

Yep, moved to Switzerland. Smaller country but much bigger space (4.5m x 10m x 2.5m). The Nathans work pretty good in that room. Although there's no significant room treatments yet, the level of first reflections is low (<15dB).

Currently running 2 subs in parallel, final optimization with Audyssey. Combined with Dynamic EQ the sound is pretty impressive. I love black magic

[gedlee]

Zurich? I thought Swtzerland was one of the nicest countries that I had ever visited. It's good not to be in several wars! Switzerland is what all of Europe would have been like if they hadn't gone nuts several times.