Help me understand "the swarm" in the broader audiophile world

Right. If we are talking about a 2 channel high fidelity system one sub never works well for a multitude of reasons.

I must have a magic sub.

I must have a magic sub.

And here I was thinking I had TWO magic subs..

@noble100 --

Hi, Tim

I think there are two types of people as dannard states but I would describe them a bit differently:
1. Those that realize we all perceive deep bass tones below 80 Hz as not directional and therefore utilize bass arrays to obtain excellent bass performance.
2. Those that believe deep bass tones below 80 Hz are directional, place a sub next to each main speaker to reproduce it and believe this configuration is responsible for their perceiving the deep bass below 80 Hz as stereo. However, they’re not realizing that their brain’s ability to associate the mono fundamental deep bass tones, below 80 Hz that are actually being reproduced by their L+R subs, with the stereo harmonics or overtones, above 80 Hz that are being reproduced by their main speakers, are the real reason they are perceiving the deep bass below 80 Hz as directional and in stereo.
In my opinion, an understandable misunderstanding by group#2 above. I don’t think it’s really a big deal, either, since both groups are ultimately perceiving the mono and nondirectional deep bass below 80 Hz as stereo.

It’s important to note that for bass to actually appear nondirectional a cross-over somewhat lower than 80Hz must be used. Most may apply no steeper than an 4th order cut-off, and as such (even with steeper cut-offs) residual information will be audible above a, say, 80Hz cross-over and quite easily render sub sources directional. A mono-coupled DBA set-up will thus require a fairly low cross-over, indeed dictate it for best results, and from my chair it’s an undesirable and limiting demand being my preference is for main speaker/subs constellations to be crossed higher, typically between 80-100Hz (which also means high-passing the mains). For this dual sub set-ups work wonderfully, insofar symmetrical placement of the subs close to the mains is upheld for best possible integration and overall balance.

It’s not about being uninformed sticking to dual, symmetrically placed subs (close to the mains) - preferably large, at that - but a choice based on preference; indeed, why do I prefer a higher cross-over between the subs and mains in the 80-100Hz region? Because I find it usually sounds better, plain and simple, and here stereo information is suddenly a factor as both it and directionality are factors from sub sources crossed no lower than 80Hz, with residual information from those sub sources audible beyond 100Hz.

Moreover: if this (i.e.: DBA) was truly about physics and adhering to that, it’s conspicuous that the sheer size and displacement area of subs isn’t taken more into consideration. This as well is a huge factor, and what may seem overkill to some in this regard is only just an approximation to sufficient headroom to others, with lower distortion and cleaner bass to boot.

May I offer yet an alternative summing-up (and this is not as much implied by or addressed at your contributions on the matter, Tim, as that from others):

1. Those that staunchly believes DBA subs set-ups is the one solution to end them all, and that the people who do not abide by this or otherwise shares this view, exclusively, are, more or less, stubborn dim wits.
2. Those that maintains that what sounds best sounds the best, be that whatever configuration it takes - also one differing from a DBA.

Different ways to skin your cat, as they say, and not least: the proof is in THE EATING OF the pudding.

¨One need not be a bass player to be inspired by Geddy Lee.¨                     @audiokinesis But Geddy Lee does not connect his bass to bass cabinets, he connects them to laundry washing machines, check the videos... just kidding.  Thanks so much for the Swarm ideas, I,m about to complete a swarm like system. I already have a two Vandersteeen 2wq subs (active)  on my system.  I just bought locally a pair of B&W CT SW10 passive subs which are 4 ohms each.  A Dayton Sa1000 amp should be arriving in the next few days.  I understand that the passive subs should be wired in series in order to not overload the amp. Any other recommendations in to completing this DBA into my system,  My main speakers are Gradient Revolutions (dipole bass)which have already a 80hz high pass between pre out to amp because of the way the Vandy subs work. I will be using the other pre output for the Dayton amp. i will appreciate any recommandation you could give me. Thanks a lot

@dannad --

In my experience, this arrangement tends to create far more issues than it solves, specifically because of what you mentioned, spectral leakage. For this to work, your speakers need to be phase aligned across the whole shared frequency range of your mains, otherwise you end up with some very strange phase cancellation effects and not just at typical subwoofer frequencies.

My speaker set-up is fully active and phase aligned by ear over their entire frequency spectrum. A friend of mine using a dual sub EV TL880D set-up, symmetrically placed, have passive 2-way main speakers (S.P. Tech Revelation) that coheres smoothly with the subs. They’re crossed at ~100Hz and phase aligned here - again, by ear - but with no issues to report in the remaining frequency range - it sounds wonderful. As you write "In my experience" - indeed the imperative words here.

Loss of directionality is <120Hz, hence why 80Hz was chosen to allow enough frequency distance for filters to work. You don’t need perfect cutoff at 120Hz, but enough that the mains are at that point significantly dominant in output.

Even with a cross-over point to the subs lower than 80Hz, 36dB/octave L-R, we’ve always been been able determine the advantage of symmetrical placement of our individual dual sub systems, so fairly rigid numerical values that would hold otherwise does little do change what’s actually perceived audibly.