Do you use a Subwoofer when listening to stereo?

That is a reasonable explanation Tim until you get to the radiation pattern of line sources. Line sources project power (volume) better than point sources. To quality as a line source the speaker either has to be taller than the longest wavelength it is to reproduce or end at two boundaries like the floor and ceiling. People think of ESL being rather polite but if you make one 8 feet tall and put it in an 8 foot room the gloves come right off. The problem for subwoofers is that if you put a point source subwoofer system under a line source speaker it will disappear as you move away from the speaker. Now, if drivers are closer together then 1/2 the shortest wavelength they are to reproduce than they will function acoustically as one driver. This is the principle behind the  D'Appolito array. Four subwoofers running as high as 125 Hz this means they have to be no further than 4 feet apart. But to do 20 Hz the array would have to be longer than 52 feet. Fortunately rooms have walls and we can use them as boundaries so as long as your subwoofer array stretches from wall to wall you are in business. Thus my subwoofer system is functioning as one large linear array subwoofer producing one large wavefront. Remember line sources do not radiate up or down. If you but the subs against the front wall there is no early reflection point off that wall so only the floor and ceiling are comb filtering. On top of this you get all the benefits of a swarm system. Moving to the swarm as is normally used with say an 80 Hz crossover, to function as one driver the the subs would have to be within 8 feet of each other which is actually doable in most rooms. If you kept them all within 8 feet from one to the next what would happen? Tim, why don't you do that experiment and let us know what happens. I have no idea. 

My experience is different but I think I might go about it differently than most. Up at the crossover point I am just listening and I do not want to hear it. The subwoofers should just disappear(remember I use a crossover point of 125 Hz). It has to sound like I am listening to one speaker. As I evaluate lower down I go from listening to feeling. Do I feel that kick drum the way I do at the club. Are those low synthesizer notes shaking me the way they should. Does the room move under low organ pedal. Hearing is one thing feeling is another. Part of the thrill of live music are the visceral sensations you get.
These sensations are missing or greatly attenuated in most home systems.

@mijostyn   You mentioned that your room has not standing waves which is a bit of an achievement so naturally you would not set up your system the same way.


Crossing over the woofers at 125Hz requires that you do what you are doing. Try crossing over so that there's no output at 80Hz and see how much correction you need.


I get similar impact on my speakers at home, which are flat to 20Hz. The problem I run into is a standing wave that causes a loss of bass on certain notes at the listening chair- they are certainly there in other places in the room! That's why I got a pair of the Swarm subs, just to break up the standing waves. The speakers can shake the organs in your chest and the cuffs of your pants and they don't sound boomy.

atmasphere:" I get similar impact on my speakers at home, which are flat to 20Hz. The problem I run into is a standing wave that causes a loss of bass on certain notes at the listening chair- they are certainly there in other places in the room! That's why I got a pair of the Swarm subs, just to break up the standing waves. The speakers can shake the organs in your chest and the cuffs of your pants and they don't sound boomy. "

Hello atmasphere,

     My main floorstanding speakers are 6'x2' planar-magnetic panels that only have a rated bass extension down to 35 Hz and also lack the ability to reproduce powerful bass dynamics.  I believe the ability of a home audio system to powerfully and accurately reproduce the bottom 2 octaves of bass and bass dynamics, like that heard and felt when listening to live music, are what distinguishes a good hi-fi from a high quality hi-end system.    These are the tactile and palpable qualities, along with a tonally accurate and detailed midrange and treble presentation with powerful dynamics and three dimensional stereo imaging, that are able to create the very realistic sound stage illusions in our rooms.
       The AK Debra 4-sub DBA system has proven to be an ideal bass supplement in my system and room, not only providing my system with the lacking deep and powerful bass and bass dynamics in the lowest 2 octaves but also doing so while seamlessly integrating with my main speakers.  And yes, it is capable of shaking the organs in my chest and probably the cuffs in my pants, if I ever become so dorky that I actually have cuffs in my pants. 

mijostyn:" If you but the subs against the front wall there is no early reflection point off that wall so only the floor and ceiling are comb filtering. On top of this you get all the benefits of a swarm system. Moving to the swarm as is normally used with say an 80 Hz crossover, to function as one driver the the subs would have to be within 8 feet of each other which is actually doable in most rooms. If you kept them all within 8 feet from one to the next what would happen? Tim, why don't you do that experiment and let us know what happens. I have no idea."
     
Hello mijostyn,

     From what I've read about bass line arrays and your description of yours, I have little doubt that it performs as well as you state it does, maybe even better than my 4-sub DBA in the right room.  I would love to try one or at least hear one in action sometime.  However, I think I'd probably need a more agreeable room and wife to do so. 
     I'd also be concerned about the effect it might have on the sound from my main speakers positioned in front of this solid bass wave and bass cancellation effects when this solid wave reflected back off my room's rear wall.

Later,
 Tim

I did when I had a surround sound set up for my Movies....then I did....but now with just 2 channel set up...nope

(by poster @mijostyn)

... It has to sound like I am listening to one speaker. As I evaluate lower down I go from listening to feeling. Do I feel that kick drum the way I do at the club. Are those low synthesizer notes shaking me the way they should. Does the room move under low organ pedal. Hearing is one thing feeling is another. Part of the thrill of live music are the visceral sensations you get.
These sensations are missing or greatly attenuated in most home systems. I started playing around with subwoofers in 1978 for this very reason. I wanted to feel as if I were at a live performance. Again, I can now move a subwoofer 15 feet just by delaying it 15 msec. I can change crossover points and slopes on the fly at one Hz increments 2nd to 10th order. You can hear these changes immediately. ...

This. Implemented with DSP tools on the fly, at the listening position and a full range of parameters, proper integration of a pair of preferable stereo-coupled and symmetrically (to the  mains) placed subs certainly becomes easier and a more likely actuality. I prefer crossing over to the mains in the 80-100Hz range (or higher if dictated by the mains and subs upper range performance permitted), as this also makes the positive effect of high-passing the mains more pronounced while generally, to my ears, making for a better integration between the mains and subs. Seamless integration is more than smooth frequency response for sure, and I couldn't imagine listening without subs implemented as lined out above, be that for both music and movies.