Subwoofers and Phase Question For You Sub Experts


I use a pair of Dunlavy SC-3 speakers, known for their time/phase coherent crossover design.

When the stars align the speakers completely disappear and there’s a sense of space and 3 dimensionality that I’ve heard from few other speakers/systems. It’s easy to destroy the illusion with things like poor placement, poor setup of room treatments, etc.

Adding subs to the setup is both a blessing and a curse. The Dunlavy’s need some support in the nether regions and a pair of HSU subs do add a solid foundation to music which enhances the overall presentation; however, it’s at the expense of some stage depth, width and image dimensionality. Placing the subs a few inches forward of the front plane of the speakers helps a little but that isn’t where they perform at their best as ‘subwoofers’.
Finding optimal room positions for bass augmentation always creates a clash with the phase aspect of integration resulting in the diminished soundstage described above.
Playing with phase settings has little impact on the problem since there’s just a toggle for 0 and 180.

Which brings me to the questions - 
1/ How does running a swarm setup, with 4 subs, affect phase/time integration with the mains? Does it create twice or half the issue or remove it altogether?

2/ Looking at subs such as the JL Audio F series with auto room calibration, does the EQ algorithm compensate for any time/phase anomaly or is it simply looking for a more linear bass response?

I don’t mind investing in more sophisticated subs so long as I don’t end up with the same problem. I’m not really inclined to mess with software and the like, unless there’s no other way.

Thanks

Rooze


128x128rooze
Thanks guys ^^
Erik’s first post got me interested in the miniDSP, which I’ve heard of many times but never really followed up with any research.
 I’m not sure it would be a fit for my system, though it sure as heck sounds tempting. I do a fair amount of equipment reviewing so need to be able to evaluate various DACs, preamps etc and I think the DSP would be a variable that wouldn’t sit well in a reviewing environment. One question I had on the miniDSP is - can it be setup via a tape loop on an existing preamp so it’s affect can be switched in and out?
I ran a Lyngdorf TDAi with room perfect a few years ago and it worked well, but again, for reviewing it’s not an ideal tool.

Agreed on the REL subs, whenever I’ve heard them over the years they’ve always seemed well integrated.
I’m still not certain that my main concern of managing phase would be resolved with a REL unless it’s one with 360 degree phase control and I find the patience to set it up manually (times two).
An auto solution would be awesome. 
Thanks again.
oh... for gear I have stuff coming in and out but my ‘static’ rig is heavily vinyl and tube:
Music Hall MMF-11 soon to be replaced with a new Origin Live setup
Manley Chinook / Zesto Audio Andros
Thor Audio tubed Pre and Power 
Aurender N100H
Sim Audio Moon 380D DAC
other odds and ends

Hey Rooze,

If you use your subwoofer in a review environment, you should use miniDSP.  What I'd suggest is you do it for the subwoofer alone.  This lets you leave every other part of your chain undisturbed.

Best,

E
Um, what you haven't convinced me of, at all, is that your problem is "phase" related.
It's the entire integration of the subwoofer to speaker and room. That's what you are describing.

Adding a mini DSP correctly will allow you to perfectly blend in the sub to your speakers (yes, including phase) as well as blend it to your room. Better with bass traps that can help drain the energy out of persistent room modes, but still effective without.
EQ is a lame idea, DSP or otherwise. But no more lame than taking advice from a bunch of guys with absolutely zero idea what they’re talking about. Which is every single post so far!

The problem you’re having rooze, and the mistake you’re making, is the same one I made and everyone makes and that’s following the conventional wisdom, because the conventional wisdom is WRONG! The conventional wisdom is based on the idea that because sound is waves and bass is waves then bass must be the same as midrange and treble. When its not.

Both in terms of how it is heard by human beings, as well as in how it works in a room in practice, low bass is a completely different animal. My subs for example all face the wall mere inches away. Try that with your precious Dunlaveys and see how it works. Which is not a knock on your speakers - NO speakers will work like this. EXCEPT SUBS. Because low bass is so very different. That’s the key idea. My distributed bass array integrates and images so seamlessly with the entire stage its freaking uncanny. It does not shrink, my room expands. It does not narrow, it envelopes. It does all this regardless of where I put them. How can this be? Its a completely different animal.

Incidentally, I am saying nothing hasn’t been said by everyone else who has actually done it. People with unfounded opinions based on imagination will say all kinds of things. People who know all say the same thing. Go read the threads. Tim, noble_100, had his a lot longer than me, expresses it a bit differently but we’re saying the same things. Sometimes when learning new complex ideas helps to hear presented different ways. Go read it all. If you want to learn.

I can appreciate where you’re coming from because I was once like these others, parroting the same nonsense, not even knowing its nonsense. I had a really good sub, Talon Roc, which I spent hours trying in vain to find that one perfect spot. Spent years searching high and low for an answer to the problem of really good bass response. The Swarm or distributed bass array solution seemed like just another likely idea at first. By now though I have learned they all sound likely at first. Even the posts above sound likely at first. They just turn out to be wrong. Which I assumed would be the case with DBA too.

Except, turns out its not wrong. It works in practice, and the science is compelling. Experiments show human beings cannot even hear a low bass note shorter than one full cycle. Think about that one for a minute. There goes your timing theory. Low bass isn’t even stereo. The subwoofer systems developer starting from first principles looked at a lot of music, found it was all summed low bass. Of course he didn’t test them all, but only a statistically conclusive sample range. Whatever. We can argue, or we can see. Hooked up running four off one mono signal sounds just the same as running two hooked up to the same amp but wired for stereo.

Again, the bass in my DBA is every bit as 3D in the sound stage as anything else. The subs actually disappear even better than the stereo pair. The stereo pair treated with Synergistic Research HFT Speaker Kit, that disappear extremely well. The five subs plopped down almost at random disappear and integrate supremely well. Because: the conventional wisdom is wrong. The DBA concept is correct.

Right now you have only two, and all the stuff you are trying so hard thinking its helping is unwittingly only making things worse. But hey, don’t take my word for it. Move your subs away from the stereo pair. Put them very near the wall, pointing along the wall or towards the wall or any direction but at you. Now this is important: place them asymmetrically, different distances from you, the other speakers, and most importantly the corners. Now go listen. See how much better it is?

The more, the better. With four or five you can literally plop them down anywhere around the room like this and have superb smooth articulate deep bass. Which unlike the others above I know, because I did it, and I heard it. I am not just blowing smoke out my, well you know.

And now hopefully this answer will make a little more sense:
1/ How does running a swarm setup, with 4 subs, affect phase/time integration with the mains? Does it create twice or half the issue or remove it altogether?

It removes it altogether.