[jtwrace]

Good placement and measurements are generally necessary too.

If you have this you can easily do 3-5 subs. 

[JohnR]

If you have this you can easily do 3-5 subs.

You can easily figure out that you don't actually need 5 subs, too...

[jtwrace]

You can easily figure out that you don't actually need 5 subs, too...

OK.  3-4 is fine but really we don't need any of this stuff in audio.   

[JohnR]

OK.  3-4 is fine but really we don't need any of this stuff in audio.   

Some claim you do. I was going to use 8, but then I did some measurements...

[jtwrace]

I was going to use 8, but then I did some measurements...

[lowtech]

Some claim you do. I was going to use 8, but then I did some measurements...

Smart man.  Generally speaking, dipole bass inherently solves so many problems.  The only real trade-off is lack of extreme SPL for LFE playback, which is not an issue for me. 

I never really warmed up to the spray-and-pray concept of using multiple subs, and all the complexity, space requirements and cost that goes along with it.

[*Scotty*]

lowtech, here is the answer to the pray and spray sub approach. Four subs in the proper locations and some applied physics.
See the PDF Doc
http://vbn.aau.dk/files/12831869/AC-phd.pdf
Scotty

[lowtech]

And pure digital time delay (for the rear channels) and four channels of amplification and four subs and measurements and EQ.  With a crossover point of ~100Hz there are proximity issues that need to be addressed with distance to the main speakers.

Anyway, I'm sure a setup like that will yield good, even performance despite its complexity.

[*Scotty*]

You should be able to this without EQ because the woofers placement and phase relationships result in flat response.
You can also not use the time delay and place the listening position ahead of the point of cancellation in the center of the room.
Scotty

[*Scotty*]

lowtech, I could not read the numbers on your graphs. Are we looking at a before and after frequency response curve as well as another piece of data in the bold line on the graph?
Scotty

[WireNut]

 
 This is not a bass mistake but more of a problem.
Every time I take the volume pass the 10:00 to 10:30 position where it just starts to sound good the
lady next door comes banging on my windows or calls the cops.
It's taking all the fun out of this hobby that I love.

[lowtech]

@Scotty - Two seperate graphs.  Top is two sealed-box woofers (1x1 + 1x1); bottom is the same woofers (2x1 + 2x1) in a W-Frame enclosure with necessary dipole EQ applied.  The bold blue line is what the DEQX processor recommends applying to obtain "flat response" (although there isn't any way to EQ the top curve to flat due to the nulls).

[*Scotty*]

From a subjective standpoint, assuming you listen to any organ music with content down to 32Hz or below, does bass energy fill the room? When I had MGIIIs they supposedly went down to 32Hz flat but when I played my copy of Virgil Fox, The Fox Touch Vol.1 on Crystal Clear Records, the deep bass foundation of the notes from the pedals was missing in action.
Scotty

[medium jim]

 This is not a bass mistake but more of a problem.
Every time I take the volume pass the 10:00 to 10:30 position where it just starts to sound good the
lady next door comes banging on my windows or calls the cops.
It's taking all the fun out of this hobby that I love.

Try inviting her over and ask her to bring a couple of her favorite CD's and you supply the wine. It usually works like a charm!

Jim

[medium jim]

Scotty:

Virgil Fox is a good test of ones bass!

Jim