I currently have a NAD C320BEE, and since it does not have a dedicated sub output, I purchased a high pass filter from Hsu Research to lessen the load on the amp and main speakers. I did this because I really like the sound of the C320BEE, but it definitely has limitations in driving my PSB Stratus Golds. The filter has definitely made the bass sound cleaner and with more impact, as the sub is now doing the heavy lifting. However, after inserting the HPF between the pre-out and main-in, the upper frequencies are just not as 'sweet'. So I gained infinitely better bass, but whatever is in the HPF seems to adversely affect the midrange on up. In short, I'd like a good integrated amp that incorporates a crossover for the sub... Any suggestions? Thanks for any replies.