DSP TO TAME THE BASS IN HARBETH SPEAKERS

Roon... interesting... I've not used it and did not realize it has that feature.  That could be a quick and easy alternative, since my Bryston BDP-3 is Roon compatible.

Won’t comment on if you do or don’t need a DSP. I’ll leave that to others who seem to know your system better than you do! ;-)

I just integrated the DDRC-22D into my system and for my room, my limited ability to treat, and my configuration it was probably one of the best additions ever. It just “brought everything” together. 
I believe the ability to tweak the response curve was a definite improvement, but the adjustment to the impulse response probably made the biggest improvement, noticeably to the soundstage. 
Good luck!

I just integrated the DDRC-22D into my system and for my room, my limited ability to treat, and my configuration it was probably one of the best additions ever. It just “brought everything” together.
I believe the ability to tweak the response curve was a definite improvement, but the adjustment to the impulse response probably made the biggest improvement, noticeably to the soundstage.

Interesting... may try it.

Atmasphere >>You might know that I'm a tube amp manufacturer...

OP >> Yes... Ralph... I will try some of your suggestions. I have your M60's and have talked with you about upgrades

This!