I decided about four months ago to step out of the standard Pro-Logic dark ages and upgrade to a DD, DTS receiver. The first one I bought was a Sony. I Don't remember the exact model but my problem was that while I liked the discrete separation, it just didn't pack the wallop my old pro-logic receiver did, especially when it came to base. It would only produce base in the most extreme circumstances, I.E. the T-Rex footsteps or a Spaceship in Independence day, and even then it was no where near what it should be doing. My subs are the now out of production Cambridge Soundworks PSW1 and its slave. I've had them now for about five years and have loved them the whole time. They sound just as good now as the day I bought them, and can produce enough base that my next door neighbor has told me I've shook his windows before, and I'm in a house, not an apartment. The only reason I tell you this is to let you know that the problem isn't the subs, because they work just fine, it has to be the receiver. Back to my point though, I took the Sony back and got the Pioneer VSX-D510 and everything feel into place up until this last weekend. I was shuffling through some disks testing out my back speakers when I noticed that that base was dropping off again like it had with the Sony. Needless to say I was a bit perturbed. First I made sure all my connections were secure, and just to be sure I even took off my sub cable and reversed the ends. I know that's goofy, but I was desperate. () Anyhow, none of that worked. I went into the receivers menu's and everything was still set as it had been since I had set it up. I increased the power to the subs, but that still didn't work. What finally ended up working was I turned off the digital in and made my receiver downgrade to a normal Pro-logic signal. This somehow gave the subs a kick in the ass and they started working, even when I switched back to 5.1. Now the subs are working again, and I seem to have found a way to fix the problem if it ever comes up again, but I guess I'm asking if this is a common problem for DD, DTS receivers, and if so, what causes it, and does this become worse over time? Any input on this would be greatly appreciated. I've never heard of this problem before, and now I've had it with two receivers from two separate companies.