Hmmm, It seems I've come to a final opinion on my new BP1503 sonosub. It is a 160l, tuned to 20hz by a 6" dual end flared port, 28" long. I used the threaded-rod-Through-the-tube aproach using 3/8 threaded rod and T-nuts on the other side. It is tightened together at the bottom base plate. With plastic feet 4" high covering the threaded rod and spacing the woofer from the bottom plate. I Eq'd it using my BFD and sinewaves(the 70hz inductance hump was met with a nice suckout that complimented the hump). I applied the house curve to it. I basically just set the eq using the raw spl data from my metre. I tried it behind the couch, in front corner and in the left corner. I only used the one side of my amp(figure 400watts @4ohms) Due to a malfunction in the other channel. My room is about 3000cuft. The front wall is 10ft across jogs in 2ft then across another 9ft. My old sub was an Energy microstar 12.1 servo sub. Think Velodyne hgs 12 without the 25hz and under bass. It was a quality sub just did not go low or loud enough. But was perfect for music. I was a little worried about going from a sealed to a ported sub but I wanted lots'O'bass down low so I went for it. My expectations for the sub were high and I was not disapointed. On most rap it was unbelievable. just a clean as the energy, louder and quite a bit lower than I'm used to(with only 400watts). It seem to have bass that was a lot more tactile in it's approach moving the couch and vibrating the pictures a lot more then the sealed energy. I then tried it with Lord of the Rings. It was down right scary. DVDs fell off the shelf doors and the wall unit were just shaking. But It was too good to be true. The next day I decided to try some different music. I listen to a wide variety of music, rap, country, alternative and heavy metal are all on the shelf. So I put in some system of a down. I was mainly listening for attack and decay. It can be said that there is quite a differnce in sound between sealed and ported cause the ported 1503 just did not have it. When the kickdrum hit it blended in with the rest of the music. It just was not as hard hitting. Oh it was tactile enough just something was missing. Kind of like hiiting your knuckle against hardwood floors versus linoleum. hardwood floors jsut sound harder. The more I listen to music the more I found this true. Metallica, ACDC all had the same lack of "slam". This was not a huge diffrence but noticable. The main problem right now is I can not seem to get it to blend with my mains as I soon found myself adujsting and re-adjusting the phase and level. It didn't sound like the bass was too low or too loud but almost like there was a hole in the upper bass frequencies between 65-85hz. But my readings with my spl metre contadict this. Actually response after eq was actually quite good.+-5db from 20hz and up. So I'm undecided on what to do. Could it be a phase issue? from that inductance hump. How would a sealed BP1503 sound? if I can not fix the problem I may just sell this driver and get a Tumult.