Woofers Gone Wild

Most likely culprit is rumble. I had the same problem and got the KAB filter referenced in the first response to your post and never looked back. To be fair, you should examine a mechanical solution to your problem first (compliance, damping, etc.), but it might very likely be the pesky rumble that's so common with vinyl causing the problem. If so, get the filter; your woofers will thank you and you'll be able to sleep at night.

Thanks to all!!!

I tried the feedback test, and all was well. So am going to give the low-pass filter a shot. The reviews of the KAB filter are pretty impressive!

Again, thanks for your help guys.

Doc

The KAB filter is very high quality and extremely transparent. I've used it in the past and my current phono stage has a very high quality built-in subsonic filter. In fact, I'd argue that you should actually experience slightly improved sound quality with the KAB.

Woofers, amplifiers and ported speakers are simply not meant to be dealing with subsonic frequencies that come into play with vinyl.

Woofer pumping is an extremely common problem for those using vinyl with ported speakers and, provided the system is well set up and located and properly matched with respect to tonearm effective mass and cartridge compliance, the subsonic filter is in many cases the only solution to the problem.