Eh hem!...Subwoofers... What do ya know?

@luisma31 --

apologies in advance as you were addressing someone else, I understand the bass augmentation can be achieved easily with the distributed array, there is such a thing as too much bass, in my array (4x10 inches not morels) I have to tune down the amps to 50 percent and sometimes plug one or two ports, I also understand that if you add more 5 6 even 8 small enclosures which are easy to hide the effect increases even more. I had 2 powered subs with dual 18 inch drivers before and it didn’t sound natural (to me), also from the amps you can change phase for two subs etc. which blends the bass even more.
I’m not trying to be argumentative with you but I respectfully differ from your opinion
Luis

No apologies needed, and I like a difference of opinion - oftentimes it makes a conversation more interesting. To "diagnose" a difference of opinion though and where it really rests some effort must be made as to the context and more precise nature of each of our viewpoints; sometimes what we initially deem ’different opinions’ is muddled by factors like lack of context and insufficient information rather than actually being in disagreement on a subject - were we to have a more "level ground" of understanding (which, for obvious reasons, we usually don’t have from the get-go). That being said there certainly are preferences, and I find them inspiring as it can lead myself to change or modify a direction, or simply appreciate and ponder other choices (just as well as it can reassure my own direction).

"Too much bass" as you write to me is simply about level adjustment rather than the capacity at hand. Practically I don’t find one can have an over-abundancy of bass capacity (as is similarly the case with dynamics), for as they say: headroom is your friend, so embrace all there is and even wish for more (to a certain point at least, but usually more than many would deem necessary). So long the enclosures themselves do not obstruct the acoustics too severely I’d have no problem adding their size or numbers as space and/or spouse permits.

Let me be clear that I only have few reservations with the multiple sub approach, the only real one being the potential lack of symmetrical placement of the subs in relation to the mains. This is controversial, it seems - i.e. mono vs. stereo bass and the supposed lack of directionality in the lower frequencies. To my sensory abilities spatiality in particular is aided more effectively via symmetrically placed subs (usually a pair, coupled in stereo) relative to and in close conjunction to the mains, and while we may not be able to distinctly assess, via our ears, where bass is coming from (depending on the chosen lower cut-off), I’d wager we can feel it via our bodies. On whether actual stereo information is available in the source material (digital), also a controversial matter, it is hardly debunked from testing a few hundred titles (a very obvious case of the problem of induction - if one were to side with named, limited testing).

On your less than favorable experience with the twin dual 18" subs, I find it hard to comment other than asking for more specifics (context) and what in particular you found less satisfying about their sound. A friend of mine is using a pair of cinema subs fitted with twin 18" drivers as well to augment his mains, and while I find they’re very capable, tuneful and rather successfully integrated, I’ve never warmed to them fully. My main gripe mainly has to do with some acoustic challenges here (generated by the floor), but also the fact that they’re direct radiators. I favor bass cabs with hidden drivers, preferably loaded via horns, but that’s another subject entirely.

Implementation is paramount. I’m using a Xilica digital cross-over that provides ample adjustment possibilities, while tentatively using DRC Designer for digital correction in both amplitude and time domain from the outset of a measured performance, choosing a target curve, specific filter types used, etc.

@erik_squires,

In my own situation, I really really don’t want to be moving a sub 6" 12 times to compare and measure. I have about 2 locations where this 100lb beast can go, and I’m going to put it there and EQ it and call it done. :)

I love my 2 PSA 1801 subs but am really tired of moving the equivalent of 2 fully stocked refrigerators every time I want to try different placements for ’sound checks’ when I have to do the ’sub crawl’. And for some reason, I’ve tired of having to look at those beasts all the time.

Not to mention sub placement is very limited - and I’ve made my mind up to upgrade/downgrade to 4 of the smallest active/powered PSA subs for - better sound and much more choices of placement. And PSA will, take PSA trade ins/upgrades and or downgrades.

@millercarbon

Morel 10", which are a nominal 8 ohms each. With four subs and two amps you can get a total 4, 8 or 16 ohms simply by changing the way they are connected to the amp(s).

Will a Y cable with 1 male/2 female RCA jacks in both the left and right sub outs (pre outs) give me 16 ohms? I assume probably not cause it sounds to simple and easy to do! Maybe 8 ohms might work for me? 

Anyway thanks for posting, as last time I was privy to your knowledge on this very issue it got a little ’Eh hem!’ heated but your sharing of this information to me - is the reason for the season... And I did take your advice and read the papers by Geddes. By the way I’m in metro Atlanta, you still in the ATL?

Does the direction of either the mains’  midbass driver or the sub make any difference?
Like if I point my mains away from a bass null would that help negate it?

No, its the physical position of the sub that dictates where the standing waves end up . Put the sub on your listening chair , now go around the room and find where the bass is loudest. Now put your sub there. The end. Leave your mains off during this. Makes it easier. And less violently loud while you figure it out.