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
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.
There is no such thing as swarm. 5 subwoofers gives the speaker dealers 5 times the profit and you"ll end up with mega bass in your room that you dont want. One is more than enough for a small room. You will not even have space for 5. Its another band aid that is being touted as the solution to horrible room acoustics that most audiophiles have. 
@millercarbon So, you state with absolute certainty that what myself and others have posted above is incorrect. Really! You are the ONLY person here who knows what they are talking about...:0(
Oh, while you are at it, maybe --just maybe, add to all of your future posts...this...IMHO. Look up what that means if you don’t already know. All IMHO.
@millercarbon thanks for the informative and entertaining post.
Just for a bit of context, I sold a pair of full range speakers last week that didn’t really need subs. The Dunlavy 3 is a great speaker that will cover well until I reinvest in new speakers.
I’m not new to the perils of sub integration nor the DBA theory, and I’ve conversed with Duke a couple times over the years about his Swarm arrangement. I’ve setup a few successful 2+2 systems and had pretty good results with so-called difficult speakers like Magnepan and Apogee.

So with that out of the way, to benefit from the content of your post I also need some context - I’m curious to know what your mains are and whether or not you run them full range. Also, you make no reference to sub quality, only quantity. Are you saying that 4 cheapish subs can produce tight, articulate and extended bass, or is there a requisite standard or level of quality and if so, can you suggest a make/model that you see as the entry point for a successful distributed sub system.

As for the ‘phase’ affect, I only hear what I hear and see what I see. With subs inline, I hear no issues other than that stated. With subs elsewhere, there is a downside, as stated. It may or may not be phase but it sure seems like it based on the effect that I hear.
Lastly, my pair of HSU have been pretty much everywhere in the room including perched up on table tops; presently they’re against the left and right walls, tight up and with one behind the front plane of the speakers and the other closer to the listening position.

It would be cool to hear from people using subs with inbuilt room equalization to see just how successfully they integrate in a 2+2 setup.

Cheers!