Hello All, New to the forum and picking up a lot I didn't know. One of the things that I did not know was that you can build your own subwoofer that will outperform anything on the market, supposedly, and I'm interested in learning more about it. I currently have a stardard 5.1 surround system consisting of a Polk Audio (SW-10 I believe) sub and the rest of the speakers are Paradigm. The front channels are Titans, center chanel is a CC-170 and the surrounds are ADP-170's. The critical specs on the Titans are sensitivity = 91 dB @ 1w, F.R. = 65 hz to 20 khz and supposedly they have a low frequency extension of 40 hz. These are all driven by a Harman/Kardon AVR 300 that puts out 60 watts in stereo or 50 watts in surround, HCC is +/- 35 amps. The room is 14'-6" x 13'-8" with a pergo floor in it, so pretty small for a home theatre set up. I would love to have a subwoofer that will reach down to 25 hz, but I am more than willing to give up some floor shaking for clean and tight bass performance. I have always heard and read that you should timbre match your speakers, but the one exception is the subwoofer, but I want to be very careful to have a sub that compliments the rest of system as opposed to over powering it or having something that just doesn't sound quite right. I'm looking for guidance on where to begin with this, do I get a sub with a 10" woofer or a 12? Sealed or vented? Two 8" woofers working in tandem? Can I accomplish this for something south of $400, or am I going to have to pony up more cash than that? The Mrs. would definitely appreciate it if I kept it on the smaller side, kind of like the current sub. I've also noticed that two of the players in the DIY sub game are defunct, Adire and Acoustic Visions, who else is out there? Any help that you folks can offer will be very much appreciated. Thanks, Adam.