Upgrading sub to get a live feel.

Right. As an example of just how well this DBA approach works, when my four were first installed all I did was plop them down facing the walls each one a little different distance from the corners. Instantly and without any adjustment the bass was deeper, smoother, faster and more articulate and dimensional in terms of imaging than anything I ever heard before. They have since then been tweaked down in level both dB and crossover frequency, and phase, all of it done by ear because even though I have a dB meter handy its the ears that rule.

Especially with bass. A lot of the problems people have getting this concept seem to have their roots in some really fundamental misunderstandings about how human beings hear and perceive different frequencies. We simply do not register timing with bass, for example, anywhere near the way we do higher midrange and treble frequencies.

In terms of level, meters and EQ fail to account for the way we hear bass volume. Look up Fletcher Munson curves. These graphs are not flat because unlike meters human beings do not respond to bass equally. The way we hear bass varies by volume. A lot. Look at the curves!

So as cool as it sounds and as much street cred as it might seem to get using EQ or meters or whatever other analytical doo dads one might buy, the truth is these things are more often than not used by people who don’t understand everything that is going on nearly as well as they think they do.

Go and listen. You will see.

millercarbon:
"Especially with bass. A lot of the problems people have getting this concept seem to have their roots in some really fundamental misunderstandings about how human beings hear and perceive different frequencies. We simply do not register timing with bass, for example, anywhere near the way we do higher midrange and treble frequencies."


Hello millercarbon,

     Yes, very good points about how we perceive bass sounds differently than higher frequency sounds.  
     We don't even perceive the existence of a deep bass tone sound in a room until the full cycle bass soundwave(a 20 Hz bass tone has a soundwave that's about 56' long) has been reproduced in the room, our ears have inputted the presence of a detected full cycle bass soundwave to the brain and our brain has processed this information as a perceived bass tone.  Any partial soundwave (less than a full cycle bass soundwave) presence detected and inputted to the brain is not processed as a perceived bass tone or any sound at all.
     Our brains also require the detection of multiple full cycle deep bass (below 80 Hz) soundwaves in the room to perceive a change in volume or pitch.  
     Another poorly understood aspect about how our brains process deep bass soundwaves below 80 Hz is the whole subject of psychoacoustics that come into play beginning with use of two subs and the main reason the 3-4 sub DBA concept works so incredibly well.


Later,


  


  
     

  

    

I was able to get the system to work and sounding good, that I didn’t want to mess with it for the evening. The solutions were I didn’t need to move any of the current front set up, they sounded great as they were, the JBL were made to not interact with the environment as much as other speakers, but I might be tempted in the future to move them. Two things that solve the lower mid range harshness was lowering the front subs crossover point to even lower. Bass response and imaging improved with the two new PB using the crawl method. They ended up behind the main seating position against the wall.

The SB front are set at 60Hz and the PB are set at 50 Hz
SB volume is at 50% and the PB volume is set at 35%.
Phase for all 4 is at 0.

Since it is all set now, i’ll play with the crossover points maybe a little more until I get the cleanest imaging.

Then I’ll try to push the volume up a little.

The results are larger sounding speakers, I went in with the expectation of wanting subs that created a lot of energy, if you’ve been to a proper set up room with big subs, you know how that feels. What I got from this set up was just larger speakers that are very accurate, detailed, and enhanced sense of space. It isn’t like a big game changer, but if you have a great sound going and want that extra headroom, this is a wonderful solution. It is a good incremental improvement for a very reasonable price, but I also got more value recapping the speakers. I also have a feeling that if you already have powerful speakers bass like B&W 8xx, this set up with small subs might not keep up. JBL have a very neutral bass and this fits.


As for demoing the 4367, I cannot say I can give a proper review of it. The place I went to had it set up for home theater, at 175watt per channel. The mids and bass were non existent. But to what I can hear. The 4367 have the JBL sound but just in large size. If you like the JBL presentation of music, the 4367 does them. The highs are extended and non fatiguing. I also can’t say it made me want to upgrade, as my current system sounds significantly better than what I heard, but it wasn’t a fair match. I can tell if the 4367 were done properly it would sound like what I have, but just bigger. Maybe when I have the itch to go larger, i’ll scratch, for now I am happy. I like JBL for their sound, I thought I could get significantly better sound as you go up, but the price to performance was not there. 

Hello Watcher,

Sorry about the side-tracks. Back to your system.

I'm glad you used the crawl method and discovered your system sounds good with the PB subs located along your back wall. I believe you’ll notice significant overall system performance by addressing the front of your system and the positioning of your two SB subs.
I suggest you try abandoning using the SBs as speaker stands for your 4319s. For best results, I think you need to treat your system as two systems, a bass system and an everything else system.
The bass system you set up first by properly positioning your 4 subs for optimum bass performance in your room. This provides the solid bass foundation for your system and most music. Its ultimate effect, after your 4319s are seamlessly added as part of your everything else system, will be to make the 4319s sound like much bigger and higher quality speakers.
You need to temporarily move your 4319s out of the room. Set all subs at 50% volume, crossovers at 50 Hz and phases at zero ’0’ for this step. Then utilize the crawl method I described earlier for optimally positioning both of your SB subs in your room, which will probably be along your front 16’ wall but not necessarily. Just locate each where the bass sounds best and trust the procedure. The goal is solely to optimize the bass in your room at this stage, so take your time and get the bass sounding the best you can to you.
Your four subs now form a completely separate and independent bass system that serves as the solid foundation for the rest of your overall system. The everything else system, consisting of your 4319s properly positioned in relation to your listening seat, is also a completely separate and independent midrange and treble system that’s going to be laid on top of your solid bass foundation.
The goal in this phase is to optimize the midrange, treble and the stereo soundstage illusion created by your 4319s at your listening seat. I strongly recommend you invest in a good pair of speaker stands for your 4319s to get the midrange and treble drivers up to the height of your ears when you’re seated at your designated listening seat and to position the 4319s on stands at least 2’ away from the 16’ wall behind them. You’ll notice that, the more you move them away from the front wall, the deeper and more 3 dimensional the stereo soundstage illusion will become. 2’ out will be good but further will be increasingly better.

I think it best we pause here until you’re able to receive a good pair of speaker stands that I believe are very important for best results. In the meantime, you could just position your 4319s on the floor, not ideal but better than nothing.
Also in this meantime, I’ll write up a procedure for the final stage of properly positioning of your 4319s and how to best adjust the volume, crossover frequency and phase controls on your subs for the seamless blending or integration of your two systems.

Is this all acceptable to you? Let me know.

Later,
Tim

Yes, thanks Tim.