Originally Posted by mtg90
I think it means an acoustic suspension, 4th order bandpass, front loaded horn, etc. only use one side of a driver's acoustic stroke while both sides can contribute in a bass reflex, 6th order bandpass, tapped horn...
Originally Posted by noah katz
I thought it might be that, which sounds like what I think is a false belief that ported boxes are more efficient because they use both sides of the diaphragm.
This may be true for dipole designs where the midrange reflections add to the overall SPL, but not in the bass; in ported designs the increase in bass efficency is from resonance.
The only case where using both sides may be true is in a labyrinth that's half a wavelength long that puts the radiation from both sides in phase, but that may be due to pipe resonance.
Just inquiring about two separate aspects; the overall alignment/design clarification, and secondarily room response integration with the existing sub system.
Having never really built, or employed anything outside the sealed alignment in my primary system (let alone a 6th order band-pass), I'm not familiar with anything other than the typical mixed alignment anecdotal warnings. Maybe these caveats don't have merit. Hence my "I'll sit over here and be quiet".
Additionally, I've no idea if this applies, but here's my take. As a general room/system subwoofer approach in normal, modestly sized HTs, one nice technique could utilize one mega-sub for the deep stuff, and a distributed-multiple sub config for the remaining spectrum upward. Since there's no advantage (to distributed subs)
in the so called "pressure region", the mega-sub could address the region around the first resonance downward, and the (smaller, placement friendly)
distributed set addresses the modal region above.
Again, no idea if this would even apply here, but as I understand it we can't fully delineate phase or time alignment down low. It's my understanding it takes approximately 40-50ms. for the brain to sense and discern a tone down around 50hz. However, taking this into the realm of hands on blending and optimizing a multi-sub system (of mixed alignments or otherwise), the effects of phase can enter the equation wrt acoustic summation of disparate sources, and the final FR across the listening positions.
All this was the genesis of my initial comments. In the hands of someone as capable as Beast, perhaps this can be an ideal test case in actual use. This is fascinating work, above both my armchair, or hands on DIY chops for sure.
Thanksedited for clarity, italicsEdited by FOH - 9/20/13 at 1:26pm