Gary,

OK - the signal going in from the 800 is probably good.

Another couple of "off the wall" suggestions:

Have you set the low pass below 120Hz? For some reason I did this (60Hz I think) and then wondered where all the bass had gone as the sub now wasn't getting anything above 60Hz just the stuff below. A lot of effects have bass quite high up the frequency range.

Also I seem to recall some people remarking that room correction seemed to remove the bass they'd previously had - have you tried with MRC bypassed?

good luck,

Chris

Lounge/Cinema, Trinnov, DSP8000XE, 4x 320.2 in-ceiling, M6 rear, 2x DSW.2
Roon Nucleus+ and 320.2 in-ceiling in many rooms (KEF in-ceiling in bathrooms)
Spare: DSP5000, 598, 562v2, 500Mk2, 518, 519, 504, 101B, M3, 861v4, 800 DVD, MS600, MC200