I will be enlarging my Living room home theater and want to add another subwoofer to compliment the Tuba HT. The actual dimensions of the room are still being figured out, but I do have some requirements that I am hoping you guys can help with. I plan on using a 4 cubic foot box from Erich. H once his company gets rolling on the flat packs. I will be making this into an end table with granite top and placing the woofer in a down firing position. I want to go with sealed to get the most low frequency extension. I have one channel of my behringer 2500 available for this build, so please keep that in my for power available. I am looking for something that I can "put the reigns to" in the Lower frequencies that the THT doesn't hit (below 16hertz) I am getting a new receiver with XT32, so integrating the new sealed sub with the Tuba HT should be of no concern with the glowing reviews I have heard recently with mixing matching different types of subs utilizing the XT32 calibration. I realize that I am not going to necessarily get a ton of ULF with a single sealed sub, but I would like to get down as low maybe 10hertz , use the power from the behringer amplifier that I have, and add some extra bass headroom with the room getting larger. I would love to hear a couple of different options, I would like to spend less than $500 on the driver. I've been trying to read up on similar sub requirements, but haven't found a similar build. If I am missing a similar build thread that is right up my alley please let me know the thread. I appreciate any and all help!