Here is what we have currently in our dedicated home theater:

Mind you, these speakers were installed seven years ago when we first had the theater built, so the models are slightly different of course -- but the speakers I provided below are the closest thing to them.

RBH Signature SI-770 (Center, Front Left, Front Right) In-Wall Cabinets
RBH TK-6 - Surround Right/Left, Rear Surround Right/Left
(2) RBH SI-12 In wall Subwoofers - Front of room
(1) Triad Inwall/Bronze 15 Subwoofer with the optional 500 watt rack mounted amplifier. - Specs: http://www.triadspeakers.com/products/iws15ps.html

Everything is powered by a Sherbourn Amplifier and a Citation 7.1 Processor/Pre-Amplifier. Our newest components include a Denon Blu-Ray to take the place of our old school Panasonic VCR above the Denon Standard DVD player. Using a JVC RS10 (On pre-order) and have everything controlled through Crestron.

Basically we're looking for more boom to take the place of our Triad subwoofer. It is in a cabinet and the dimensions cannot exceed: Size: (H x D x W): 23.94" x 22.44" x 18.125". We do have Aura Wireless Bass Shakers built into our Palliser HT seating, but we're basically looking for something with a bit more low end grunt.

Our most recent home theater contractor has recommended the JL Audio Fathom F113, however it is a bit more than we would like to spend. Any suggestions? Is this the ultimate sub with 2500 watts of power, or can I find something better for cheaper, that will be at par or better with the JL Fathom?

If you can truly afford the Fathom, buy it, it is worth the money spent due to your application.

Is it just a coincidence that your size restrictions happen to match EXACTLY to the dimensions of the MFW-15?
http://**********/component/page,shop.product_details/flypage,shop.flypage/product_id,265/category_id,9/manufacturer_id,0/option,com_virtuemart/Itemid,37/

In any case, I would also consider the ULS-15 from Hsu.
http://www.hsuresearch.com/products/uls15.html (http://www.hsuresearch.com/products/uls15.html)

No coincidence, I also own a MFW-15 from Av123 -- that is kept in another room. ;)

How is the wireless connection on the HSU subwoofers though?

No coincidence, I also own a MFW-15 from Av123 -- that is kept in another room. ;)Is there some reason you don't want to use another in this room?

How is the wireless connection on the HSU subwoofers though?It works just fine, if that is what you are asking.

Yep -- it's the kid's playroom. They use it for their friends come over and it's in the cherry satin finish that blends in with the furniture in that room. Wife doesn't want me moving it out of there so guess it's time to purchase another sub for the HT. :D

I've looked into the SVS 13 inch Ultra that they offer but it's too deep of a sub at 27 inches and won't fit into the cabinet designated for it.

I'm really leaning towards picking up another MFW-15, or possibly the HSU that was suggested.

The JL Fathom 13, though it will fit fine, it is a little bit rich for my blood. I've found a used one in my area for $2,300. I can pick up two MFW-15's for that price shipped.

man..i really want to hear one of these fathoms or gothams...i just gotta know if a sub can be worth so much money..or if it's all just hype