Driver for seat-to-seat helper subs

[Jonas_h]

I am moving my home theater into a basement and want to have the lowest possible seat to seat variation. I already own 4 S1S-EX subwoofers but I dont know if I am able to put them in each corner/midpoints as Harman recommends. So the four will go behind the screen, and I will need some "helper-subs" which is easier to position than the S1S-EX's.

I know JBL Synthesis uses the S4S subwoofers with 2x10" for this purpose, but I was wondering if I could do a DIY solution instead. I already use the 2226H drivers in my LCR's and I think they have the same kind of bass as the 2242h's. But with an Fs of 40hz, I think it would be hard to make such small enclosures I need. Are there other JBL drivers which have the same "sound" as the 2242H and will work in smaller boxes? Sealed would be preferred. It does not have to go much below 30hz, but down to 30hz, it should be able to produce a descent amount of SPL.

[DogBox]

Hi jonas h, Have you had a look at the design of the JBL B460? It uses the 2245H. Also needed would be an active filter to minimize excessive cone motion when getting down around 30Hz at high SPL. They used the BX63 Electronic Dividing/Summing device, which does what I said to allow the 2245 to give its best without being destroyed by Godzilla on a rampage!
http://www.lansingheritage.org/images/jbl/specs/home-speakers/1983-b380-b460/page3.jpg should start you off!

DogBox

[Jonas_h]

The depth of the driver is too large.

I was looking to do a enclosure like this one: http://www.procella.citymax.com/f/P10Si_Tech_Sheet_v1.2.pdf
The specs on the Procella sub would be good enough to be used as "balancing subs", but I would like to have drivers which match the JBLs I currently have.

[DogBox]

Hi Jonas,

Man, that Sub's thin! I can see their design objective, but [& it's a biggie] JBL didn't design their subwoofers to be squeezed into little boxes but having huge cone-excursion to provide the necessary SPL @ the frequencies you are talking about. If you take a look at the 'Specifications' sheets of some JBL drivers, you'll notice that, while the fs is at a low frequency the Qts is really low at about 1.7~2.0 and the Vas is quite large adding up to a driver needing a large enclosure for proper loading and assisted by port venting to gain the low frequencies. And, importantly, used electronic crossovers so the driver wasn't over driven- 24dB slopes manditory! It's how JBL designed their drivers. Give them room to breathe and they will pump out the low stuff effortlessly! Take a look at some of the boxes that were using the drivers you have, and check out the size of them. If you can find room for them, you'll have the best sounding hometheatre setup out! The 4645B uses the 2242H....
http://lansingheritage.org/images/jbl/specs/pro-speakers/1982-theatre/ have a look at this; I go weak at the knees and start to drool...
Their ain't no substitute for horsepower!

Steve