I use an Energy e:XL-S10 10" subwoofer in the following stereo system: NAD C 370 stereo integrated amp Totem Arro floorstanding speakers Energy Active Crossover (EAC) The EAC allows me to connect the subwoofer to the integrated amp. Here is how I do it: * pre-out 1 from C 370 to inputs on EAC (two RCA cables) * outputs on EAC to main ins on C 370 (two RCA cables) * sub output on EAC to XOVER INPUT on e:XL-S10 (one subwoofer cable) I have the crossover on the EAC set to 60 Hz, as per the dealer's recommendation (I bought the EAC and the Totem Arros from the same dealer). This set-up has always worked, but it seems now that the subwoofer is dead. With everything plugged in, the green "active" light on the back of the subwoofer is not on. Ironically, if I unplug the subwoofer, the light will go on and then dim after about 10 seconds. I also use the subwoofer in my home-theater system in the same room. In this system, I use a Sony STR-V444ES receiver. To make things simple, I have a subwoofer cable for each system. Thus, when I want to switch between systems, all I have to do is switch subwoofer cables in the back of the subwoofer. I always unplug the subwoofer before switching cables. However, on a couple of occasions, I did not wait long enough for the subwoofer to power down before switching cables, so I heard feedback. Could I have fried my subwoofer? In listening to music where the subwoofer was active in the past, I hear nothing now. Any thoughts on what happened? Thanks in advance.