Ok, here are the facts. Hopefully, some of the experts here can help me out. I have a Marantz SR-19 THX reciever. Crossover is fixed at 80. I have an Energy 8" sub. I can't go any larger right now because I live in a luxury apartment building and don't want to blow my neighbors away. I have my speakers set all to small as per the recommendation by Marantz. The sub has two different choices for Low Level Input: Subwoofer Input or XOVER Input. Subwoofer Input is what I am using right now and I have it set at the highest point...100HZ. After reading some of the threads on bass management, I decided to give it a try through the XOVER Input. My problem is that I found it very hard to properly calibrate the sub levels properly when using the XOVER Input. According to Avia, my levels were way off and I couldn't seem to get them right. I have much better success setting the levels when I use the Sub Input and set the volume on the sub. My question is which do people here think I should use? Should I be using XOVER Input (which as I understand it then turns all bass management over to the SR-19)? And if so, does anyone have any thoughts on why calibration is so hard in that scenario?