Are big subwoofers viable for 2 channel music?

Tyray asked: "Can a customer use their own passive subwoofers of choice?"

You can totally use your subs of choice, active or passive. Here is the amplifier that I use to drive my passive subs, note that it has a single band of EQ and a switchable 25 Hz "bass boost" circuit, which may come in handy with sealed subs:

https://www.parts-express.com/dayton-audio-sa1000-subwoofer-amplifier-rack-mountable--300-811

Tyray: "Or do I have to use AudioKinesis designed passive speakers for best results?"

I think the subs I designed work well for this application, but they are NOT required for good results. I don’t like to make claims like "best results" because in this hobby there is always something better... I’ll only claim "best I know how to make at my price point given where I think the goal posts are."

Tyray: "As I’m trying to understand if you would need to ’customize’ your swarm peripherals, amps, speaker wire, crossovers and any other hardware to work with the subs a customer may propose."

I don’t really "do" custom Swarm systems wherein I don’t at least supply the passive subs, but it’s not rocket surgery. Briefly...

Spread your subs asymmetrically around the room, perhaps with one (but no more than one) in a corner, and bonus points if you can raise at least one sub up off the floor such that it is closer to the ceiling than to the floor.

(If you prefer, you can also use a symmetrical configuration - see Todd Welti’s "Subwoofers: Optimum Numbers and Locations" on Harman’s website.)

Any subs which are fairly far from the main speakers, you want their top ends to be rolled off fairly steeply no higher than 80 Hz, so they don’t betray their locations by passing audible upper bass/lower midrange.

I usually find that reversing the polarity of the sub farthest from the main speakers tends to improve the in-room smoothness, but in a very large or open-floorplan room the result may be deficient in the bottom octave.

If you don’t have test equipment, when setting the controls on your subwoofer amp(s) by ear, the sequence is: First set the level, then the frequency, then the phase. Cycle back through this sequence several times to fine-tune. Credit to master acoustician Jeff Hedback for teaching me what the proper sequence is.

Duke

With Subwoofers the moor the better it distributes and even out unbalances in rooms .the best sub on the market period at $1500
or 7nder is the new SVS 3000 SB it has the latest 50+ bit processor that monitors control the drivers movement, plus processing with a good app great heavy duty driver and at $995 delivered buy 2 and even get $100 off 13 inch driver that weighs over 25 lbs and goes to 18 hz ,it has a short long pole piece 
for low volume great control ,when you crank it up it uses the outer 
part ,no one else is doing this, the ultra is the flagship at $2500
with a 16 inch driver both are best in class and won a Tons of awards  free shipping, 45 day audition ,free return and refund if not 
totally happy. And a 5 year warranty I sold my $1600 JL Audio 
for the 3000 they are excellent l

big_greg:
"Tim, it might surprise you to hear that the system with the best bass I've ever heard consisted of two subwoofers and that they were crossed over at 120. I was quite surprised at the crossover point, but there was no denying what I (and a number of other pretty serious enthusiasts heard).

There's more than one way to skin a cat. "

Hello big_greg.

     As far as you, the readers and the authorities know, I stopped skinning cats years ago. Shhhh.
     I am surprised by your comment about the best bass you've experienced.  You're correct, I wasn't surprised that only 2 subs were utilized because I know very good bass quality is very attainable with 2 subs if you only require very good bass at a single designated listening position in the room.  Utilizing 4 subs in a distributed array typically further improves the bass quality, integration and it provides this high quality bass throughout the entire room, not just at a single 'sweet spot'.
     Just like you, I'm most surprised by the extremely high crossover frequency of 120 Hz, which is generally considered upper bass, is well above the 80 Hz threshold at which bass tones become localizable.  Most individuals should be easily able to discern that 120 Hz tones are originating from the 2 subs which normally negatively effects good imaging.
    My main speakers have rated bass extension down to 35Hz.  I run them full-range and have my 4 subs crossed over at 40 Hz.  I'm completely unable to localize any of these subs in my room, which is what's desired, but I am easily able to localize each of them as the crossover frequency is raised beyond about 80 Hz. This significantly and negatively effects the sound stage imaging in my room as expected.  
     I cannot explain why the very high 120 Hz crossover setting in your 2 sub audition didn't significantly and negatively effect the sound stage imaging in the room.  Can you?


 
  

Tim, the last time I talked about something like that having to do with cats my post was deleted by the mods, so I'll refrain.  I should have asked more about the why of the crossover setting.  It just came up in passing as we were heading out the door.  I'd like to get that guy to come over to my place and help me get my subs dialed in better once things return to whatever the new "normal" is.  I've tried a high crossover setting with my subs.  It didn't sound bad, but it bothered me that the sound was localized.  I could "hear" the two behind me.  In my friend's setup, I couldn't tell at all by listening where the subs were.  He had a lot of room treatment, so I'm assuming that helped.  His system sounded fantastic.

Would you mind describing your setup and the AudioKinesis gear used?

Tyray: I happen to own also Audiokinesis Azel's speakers, to be honest I was shopping around for speakers not subs and found Duke (and Jim Romeyn) at RMAF 2018 (or 17?) and from all the rooms I visited that was (to me) the best sounding room, I'm not saying AK's speakers are the best, many other manufacturers make good speakers as well, we all know at these shows the hotels rooms have their own problems and limitations so what Duke have done with his speakers is give you the opportunity to tune the speakers (and subs) to any room with no external analog or digital DSP, this could be done with RoomEQ as well (which has its own limitations like format changing etc), anyways apologies as I have a hard time following thread directly and I deviated here, my Swarm sub system was a byproduct as I was shopping only for speakers and had subs already PSA and SVS.On point. I have Azel's speakers which consists on a beryllium compression driver for highs and mids and a midbass woofer for lower mids and bass down to 55 Hz, this midbass driver reproduces bass with extreme tonality accuracy on the low registers it reaches, to me it is one of these speakers "forte", the 4 passive subs I have are crossed around 65 Hz, Duke's Azels are standmounts on top of what he describes as a SuperStand which contains one sub and one (what he calls) space generator but that is not relevant here, just that the sub is in the stand saving space of having a separate sub. His subs have very very low footprint but what they lack on area they have on tallness (hence my wife putting ornaments on top) the good thing is you can fit them anywhere.
So four subs and two 1000 W amps (the one Duke referenced above). One amp powers the 2 left subs one amp for the right 2 subs. Crossed at 65 Hz, gain for each amp around 50% (more than that it provides still accurate bass but not needed and unbalances the system IMO), there is about 90 degrees phase difference between the left and right subs on my system.
I'm enclosing some pictures at this link
bit.ly/luismasystem
I consider myself an audiophile but I don't have as many years as you most had to deepen your knowledge on audio systems etc. my knowledge of all this is superficial and if you want details I'm sure that Duke will chime in
By the way @audiokinesis Duke thank you for providing the great explanation of your thoughts on sealed vs vented which always made me think about that paradigm, I understand 80% of it, based on what you are describing and since I have a "difficult" room based on REW measurements (I don't know where did put the response curve screenshot) could you say (Duke) that your vented subs overcome the irregular room response just as well as sealed or better because:1. I'm using 4 of them (vs 1 or 2) which requires less gain and allows for bass waves cancelling each other at almost most listening positions2. They are designed targeting the 20 - 80 Hz band better to integrate with your speakers (or any speaker which drivers reach down only to 80 Hz?)
Tyray: I ranted through my post and wasn't able to explain directly your question, hope you could gather from my writing the essence of what you want to know about my system. I sold my PSA and SVS (great subs by the way) for the superior performance of 4 smaller subs and the convenience of saving space due to footprint and integration with speakers and cost savings over 4 equal subs from different manufacturers.
PSA and SVS are great brands again and if you have the space and the money definitely you could do good as well with these
If you look at my system my source is completely digital (at this moment) but EVERYTHING else is analog controlled, no DSP or anything and I looked at MiniDSP, DSpeaker, Trinnov, (there is one I forget the name $4000 - $6000 which was IMO the closest one for me to consider) and since all of these rehydrate digital (with its limitations) I decided that RoomEQ using analog devices is better for my system than going digital downstream, so I avoid that when possible.