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.

thewatcher101

They are 6 inches away from the wall,

You keep mentioning hardness in the lower midrange. This right here could be the reason. We all have room constraints so maybe this is forced, but if its not then you might want to try moving the speakers in a few feet from the side walls. 

Being so close to a side wall the critical first reflection arrives within a millisecond or so, well within the roughly 4 milliseconds within which the human ear perceives sound to be coming from the same source. What this means in plain English, its smearing and ruining your imaging.

But that's not all. That's so close the wall is practically acting like a horn, reflecting and reinforcing the speaker but not in a good way. I could never understand your comment trying to link sub placement with this low midrange hardness. Can't see it happening. What I can see happening though is the bass changes distract from hearing the reflection problem that is there all the time. Move the speakers and see.

While you're at it get them off the subs. You'll get better bass and improve imaging in one fell swoop.

thewatcher101:

The room size is 16x30. The speakers are placed on the 16 side, and I sit about 11 feet away from the speakers. The SB are located right under the main, 6" from the wall.

I'm reading this as your main speakers are 6" from the wall??? Can't be right.

Subs right under, or even real close to the mains is another problem. Some might think this is necessary for timing or whatever. Do a little research. Timing is not a factor with low bass.

Instead what you want is exactly the opposite of timing: a lot of randomly spaced sources. Putting subs close to mains is by duplicating the location robbing you of a lot of the improvement you'd otherwise be getting. Move em.

The SB-1000 are set to about 65Hz to blend, zero phase, 60% volume. I’ve always found very clean and articulate bass at this current settings, and anytime I’ve made an adjustment, I’ve dialed it back to these.

Easily the biggest problem or pitfall with subs is trying to hear them working. When done right you don't hear them at all. No one listening to my system will have any idea there are 5 subs. No one will have any idea there are ANY subs! They certainly will have no idea there are two way back off to either side and behind them. 

My first big mistake in setting these up was getting the levels way too high. Its hard because a lot of recordings have no really low bass to speak of. So its real easy to wind up with too high levels because you used the wrong recording.

Test tones and meters aren't much help either. This is because the way us humans hear really low bass changes depending on volume. See Fletcher-Munson curves. Because of all this what I find works best is just relax, listen to a lot of music at whatever volume levels you like, and don't try and get it dialed in too fast. Be patient, make very small tweaks, and don't try and make any one recording sound perfect.

First test just running one additional sub (3), placed on the left side besides my seat, set at 60Hz, played with gain to peak bass, and 60% volume. The biggest difference is an increased amount of headroom, the speakers felt slightly larger.

Yes. "The biggest difference is an increased amount of headroom, the speakers felt slightly larger." Exactly! 

The bass that comes from adding more subs is completely different than the bass that comes from adding a bigger sub. The difference is exactly what you said, the speakers sound "bigger". 

The thing about really low bass, the frequencies are 40, 80 feet or more in wavelength. Because low bass has such a long wavelength the only places you really hear them are in huge auditoriums or concert halls. Walk into any huge space like that you can tell its a huge space even with your eyes closed. Because of the fundamental low bass resonance. You feel it. It tells you you're enveloped in a vast space.

Now with one or two subs, even really good ones, the low bass reflects and cancels and really cannot truly exist. So you never get this feeling of envelopment. With three or more subs though at some point there are enough extra sources to overcome the cancellations and the really low bass is believably there and you do get this sense of envelopment. This is what is making your speakers sound "bigger".

 It blends well in this position, but you can feel the physical bass being directional. That feeling makes you slightly detract from listening.

Not sure what you're doing. The only time I ever was able to localize a sub the crossover was way too high. Set properly all my bass is incredibly, ubelievably precise and localizable. The bass. Not the speakers. 

Now sometimes the bass on the recording just happens to be coming from where there's a sub. This happened a couple times and bugged me until I realized its not the sub, its the recording. Patience.

Second test, quad sub, placed along side seating position against the wall. Similar settings, but with 45% volume, because the wall gives it a boost. I get a nice spacial balance, but I could not get them to blend in this position. At those settings, I got a bit of harshness in the low regions.

Probably this is just too much bass. Every additional sub adds both extension and headroom- and volume. Adding a sub requires turning down the level on all the subs.

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.

Some points about the Swarm/Distributed Bass Array approach that have been made repeatedly, but obviously due to not sinking in need to keep being made, over and over again:

1. Its not THE sub. Its HOW MANY subs.

2. More small cheap subs is far better than a few expensive subs.

3. This is so true that even really small subs that take up hardly any room, ie can fit easily under furniture, will work better and take up less space than the normal huge sub everyone thinks they need.

4. The same amount of money spent on four subs will outperform the same amount of money spent on just one.

5. Yes even if its not very much money.

6. Sub (note: singular) is crucially important.

7. Subs (note: plural) by the time you get to 4, where they go hardly even matters.

8. Everyone who has actually tried it knows what they’re talking about and can’t stop talking about how great it works.

9. Everyone who has not actually experienced it should maybe every time they are about to write something on the subject first write: Of course I have no actual experience to base this on, BUT....

No amount of room placement ever gonna make two speakers, or even two speakers with a sub, or even two speakers with two subs, sound anywhere near as good as two speakers with four subs. Never. Gonna. Happen.

Go with four though, and surprisingly they go with everything. Placement becomes a virtual non-issue. System matching? Total non-issue.

Search around, every single one of us who has tried this is super happy. Yet the particular subs we are using and the systems we are using them with are all very different.

Why? Because it works. As opposed to everything else, which does not.

Tim is right about the DBA/Swarm subwoofer solution. The one I built with 4 Morel 10" woofers and the Dayton amps for under $3k gives more powerful, deep, articulate and smooth bass than anything I ever heard anywhere even from vaunted state of the art speakers costing ten and twenty times as much. Using four subs spaced around the room works so much better than the old-school paradigm of one or two that it doesn’t hardly even seem to matter what quality or how much you spend, until you get to three or four you’re just never gonna get there.