Do you have your speakers set to "small" in the receiver setup? Often the auto setup in receivers turn your speakers to large. You want all speakers set to small with an 80hz crossover in the receiver. You want the crossover on the back of the sub cranked to the highest setting, to get it out of the way for the receiver to manage.
If you ran the auto setup, the sub and speakers should be calibrated to the correct SPL levels, but it might not be a bad idea to verify with a Radio Shack meter.
Do you have the distanc (delay) setting in the receiver correct for the sub. Looks like it would only be a few feet from the couch.
Have you tried adjusting the phase switch on the sub. Normally, you want it up near the front speakers for best blend, with a 0 phase setting. You might try adjusting this to see if it helps.
Keep in mind most music does not have lowwww frequencies, unless you listen to rap or r&b. What about movies with low LFE, how does it work for those?
Is this an older 350 or one of the new 350's? Either way you want it calibrated to the same levels with the receiver pink noise tests.
