I have a pair of subs in enclosed cavities under my equipment cabinets. Here
is a picture of one:
is a pic of the overall framing early on:
is a closeup:
A few comments:
- You don't mention if the bottom of your rack opening is directly on the floor (i.e. no framed in bottom) or not. If you are still in-process, then try to make it so if you plan to put a sub in there.
- Frame the enclosure as rigidly as possible... glue, screws, and thick plywood.
- Make sure you have a front firing and/or ported sub
- I lined the inside of my enclosure cavity with 1" Linacoustic
I'm very pleased with the results....
(You can slick on the links above for more pics...)