The Arcam has a headphone jack. That is what I was suggesting. It goes through different amps and trying it would help understand if the 40 watt/channel was the issue. If there is plenty of bass through the headphones, then there is an issue with the output amps for the speakers. If they are equally muted in the bass, then it would be some other issue. Not definitive, but might help fill in part of the puzzle.
Given that the DRCT mode helped, what happens when you turn it off and adjust the bass and treble separately?
Given that the DRCT mode helped, what happens when you turn it off and adjust the bass and treble separately?