Upgrading sub to get a live feel.

The 15 inch woofers in the 4367 cross pretty high up some where around 700 Hz I think. They are a pleated short throw design which will not go well below 40 Hz. Putting 2 high quality subs under them would clean up the lower midrange to a substantial degree and add that lower octave. You could also plug the ports which might make further improvements. I would rather two high quality subs than four cheap ones. Room control is a must for thewatcher with two subs as his room is very square. Make yourself a plan and stick to it. Messing around for the sake of messing around is a waste of money. 

The truth is that any audio and music lover, who even briefly experiences
the state of the art bass from a DBA, would obviously do whatever it legally or illegally takes to get the money and find the space.
    The concept works that well and I'm just trying to spread the word.

So would anyone who hears a well integrated sub in a small living room vs. no sub or a poorly integrated one. Sadly, very few people have ever heard this.

More than one way to skin a cat.  Not that I'm endorsing cat skinning by any means.  I like cats.

If you want a sub that actually does go to 20hz, find a used Mackie HR120...they were designed for studio use as opposed to their live sound stuff (and they’re around although not made anymore)...I found one in a local music store that sells used gear and they had no idea how to use the thing. About 150 bucks later I brought it home and stuck it in my music studio...amazing...I use a couple of REL subs in my listening rig, and hooked up the Mackie in that system out of curiosity (no small feat as it weighs 92 lbs) and realized I really don’t need 19hz in there and prefer the main amp signal driven RELs, but man...a great sub. 500 A/B watts, and a plethora of adjustments available...12" down-firing EAW monster woofer, 12" front firing radiator, balanced and single ended inputs. Get four of ’em!

Dear @thewatcher101 : what @mijostyn posted about the 4367 crossover frequency is truly relevant and a main parameter to take in count.

It crossover 700hz and that means the the IMD level distorions are really high in the mid range and up to it due to the developed harmonics.

The main target to add true subwoofers to any passive speakers is that the IMD generated for the speakers woofers goes really down and when this happens your room/system quality whole performance goes to the " sky ": nothing less, you will discovery a new quality level performance even if you think you know very well the resolution of your room/system.

A " side line " adding true subwoofers is that we can get true low bass frequency range to honor the MUSIC.
Rigth now you don’t have neither of those trgets.

In any room/system MUSIC belongs to both frequency extremes. As better the overall bass range and HF range as better not only mid range but way better whole system resolution and system listening quality


You can read something about here and why:

https://forum.audiogon.com/discussions/do-you-think-you-need-a-subwoofer/post?postid=310058#310058

Now, if you normally use your system to listening MUSIC then normally you listen MUSIC at one seat position because at mid range/HF ranges we can have perfect response in those frequency ranges at one the seat position.

For that you only need two true subwoofers ( the ones that goes down to 16 h. ).

The Harman Group ( JBL, ML, Revel, etc, etc. ) proved that through scientific research. Here the link:

https://pdfs.semanticscholar.org/00da/51387c572cfd27c0256cb15e44e976a1a72e.pdf

from those white papers:

" " Four subwoofer at the wall midpoints (configuration 11) was the best practical configuration in terms of MSV. Two subwoofers at opposing wall midpoints (configuration 6) was nearly as good and also offered stronger low-frequency support. These results appear to be generalizable to reasonably dimensioned rectangular spaces [19] . ""

The manufacturer of DBA solution ( Audiokinesis. ) posted in other subwoofer thread:

""" You can get good bass in one sweet spot with two equalized subs. ""

No one needs more than two true subwoofers for one seat position. The key words are: true subwoofers. Not the ones you own or the ones noble100 owns.

Wait for your 4376, do it a favor and don’t waste your time or money before those 4376. Patience is always worth to do it for its rewardings to collect.

Regards and enjoy the MUSIC NOT DISTORTIONS;

R.