My Canton subwoofer from the CD-1 package has been working no problem connected to the amplified input on the sub from my Sony DAV-S550. I've just got a Denon AVR-1905 and connected the subwoofer out on the Denon to the line in (using the Y splitter) on the sub. There is a very weak bass output, but thats only on full volume on the sub. Its about 10% of the volume I had before!!! also won't auto detect the signal, i have to manually turn it on. Any ideas, is the amp in the sub dead? have I missed something?