Upgrading sub to get a live feel.

I agree with a lot of what has been said but in my experience ported subs for music reproduction is a no-no. Using ported subs can create phasing issues. You will hear thick rich low end but will loose punch and clarity, specially if your main speakers are also ported. I do not have any experience with a DBA system ( and I wish I did) so this effect maybe reduced. I do achieve a very live feel with my system with a pair of SVS SB4000s and a pair of book shelf speakers.

Hey Tim, its great to read you love your four subwoofers.  I may be wrong but it kind of seems like I read it before.

Tim,

We do have a pretty good idea on the OP's preference for bass levels, he has a pair of SB1000s and is not satisfied.  To get a significant feeling of increased volume, he needs to pick up 10db.   Adding two more SB1000s will only net him about 6db (again, because we are not co-locating).  The PB-1000 a little more.  Two Seaton Submerssive HPs are capable of 115+ db at 20hz without room gain.  By 30 hz, we are well over 120db.  We do know this will keep up with his current speakers as well as his future speakers.  

Audiorusty,

You make an excellent point about the phase issues with vented subs.  While a well designed vented sub can have virtually the same transient response as a well designed sealed sub, the vented has far more phase change through its range.  Sealed subs are easier to integrate, especially with multiples.  

jetter:
"Hey Tim, its great to read you love your four subwoofers. I may be wrong but it kind of seems like I read it before."

Hello jetter,

     Okay wiseguy, I get the sarcasm.  Yes, I may have previously mentioned a few thousand times on various threads just how amazingly well 4-sub DBAs actually work.  
     Sorry, but I felt the overwhelming responsibility to spread the word to the humans, kind of like that long-haired bearded guy a few thousand years ago spreading the word about his father.  
     What can I say?  I am a true believer.  The only difference being I'd likely cut it out if threatened with crucifixion.  I'm a true believer but have my limits.

Tim

Seems like what I have heard before is phase blah blah blah timing blah blah blah EQ dB blah blah blah. Same blather that has been around everywhere since like forever and never worked anywhere ever.

Because it can't. Because: physics.

The one thing I never heard anywhere ever before, until reading it here, is using four (or more) relatively small subs spaced at random around the room. This it turns out is not new, as in it was not invented just the other day, but is new in the sense of hardly anyone knows about it.

Which seems primarily to be due to it being such a different approach, which makes it challenging for people because lets face it people are lazy even (especially?) when it comes to thinking, and this definitely requires thinking. Anyone can just buy bigger, its almost a reflex and requires near zero thought process. Understanding the things like Tim is talking about, not just acoustics but psychoacoustics as well, well that is not exactly a knee jerk reaction.

Which would be all fine and dandy if that's all it was. Not being bothered to think, okay. Not being willing to admit they've never even tried, all right. Ignore it? Fine. Be that way. But, belittle?

Which come to think of it, heard that one before too. Goes like this: blah, blah, blah... or is it yada yada? Either way pretty sure the most apt reply is yo mama. Tim of course would never stoop so low.