[Hakka]

MY equipment:

Denon 3803 receiver
Denon DVD 2200 dvd player
BFD1124p
Behringer A500 amp

I use a coax connection from the dvd player to the AVR.

If I connect REW directly to the BFD input I get a flat response down to 10hz.
If I connect through the 3803 I get a shrp rolloff at 15hz.

I was looking at the thread over at AVS with the Spectrum Labs waterfall plots of bass heavy scenes, these measurements are taken from the sub out jack on the receiver, they are all showing response down to single digit frequencies. There are a lot of different people doing these plots on lots of different sytems. I have also seen numerous posts here showing AVRs going well below 15hz.

I had a look at the specs of my Denon equipment. The DVD player freq response goes to 2hz, the receiver is listed at 10hz for the analog section (in direct mode). I tried direct mode (I normally use Stereo) and still got the sharp rolloff at 15hz.

Unfortunately I have no way of running a REW sweep in DD/DTS mode so I can't tell if it any extends lower, my soundcard does have an optical out so I could try a digital connection to the AVR. The only other thing I can think of is doing the same Spectrum Labs plots as the other guys and see what's missing down low.

Any other ideas on what could be causing this?

Hakka.