OK. I built my sub. It is a ported 118L box. port is 4" and 17" long (uncut flared port kit) so it should be tuned to approx. 20.5 hz. Driver is a SHiva Mk IV powered by a PE250w amp. It is bad! My yamaha 8" sealed sub plays louder. It sounds really distorted like it is blown at low levels. If I can get it to go louder it sounds like it is bottoming out hard but what appears to be very little travel. Nothing is hitting the back of the woofer. I have tested the amp by powering an old center speaker I have. It seemed to go ok. I had to turn the crossover all the up of course. I tested the driver by hooking up to my main speaker wire. SOunded bad cuz it was not in a box but seemed to function fine. I have played w/ the phase, gain level, and the crossover. I have turned the crossover all the way down to the 40hzs and the gain to about 1/3 and still it sounds bad. My receiver is couple yrs old. Has a sub pre-out (rca) but no menu to for settings. The box is stout. No leaks. The bracing is good unless I have to much. You can see pix here in this thread http://www.hometheaterforum.com/htfo...hreadid=184657 or here at this website. http://dodgetrucks.org/cgi-bin/index...pe=2&si=pne123 it is a 14x12 room centered in the middle of the 12' wall. any ideas? please help. my wife is really starting to look at me funny. I really thought I had this nailed. thank you in advance.