I recently received one of the new customer port/adapater ring combinations that SVS has just started offering for the 25-31PC line. I assume they're making them for the other two powered subs, as well. I wanted to go even lower in my room than the 25-31PC was currently doing. The bottom line is...it works! Here's a cut and paste of my note to Tom: First of all, I love it. First thing I did was put on the Stryke Basszone test CD...I heard (and/or felt) tones down to 17Hz that I hadn't before. Amazing! Since then, I've been running through the usual tests, Toy Story 2, Apollo 13's liftoff, U571 depth charges, et al. Right now, I'm on the music side of the SVS equation. Just listened to a little Van the man. Now onto Marvin Gaye via Luther Allison. All great. In fact, it may be just my imagination but it seems to enhance the entire listening spectrum, not just the bass. Or it could just be the re-calibration. I recently got the BFD 1124 so I've been adjusting a LOT lately. Hard to quit.