DSP TO TAME THE BASS IN HARBETH SPEAKERS


I need an audiophile quality DSP with balanced connections (XLR / AES) to tame the bass bloat in my Harbeths when driven by tube amps.  I’ll spare you the details... but... just need a quality 
DSP with balanced connections.


bassdude
The Minidsp DDRC-22D does everything in the digital domain since you say you don't want a DAC. 
There is no problem with my Hegel H590 or Class D Audio SDS 470C amps, just my ARC Ref 150se. So... it's not the room... its the amp.
You might know that I'm a tube amp manufacturer (that also holds a patent in class D amps as well). Take it from me on this bit (since the solid state amp is fine, we'll assume that a DBA isn't needed): speaker cables can affect tube amps a lot more than they affect solid state! So I have two recommendations: try several different cables and keep the cables as short as you can: under 3 feet if possible, and make sure the connections are tight. I would also try different taps on the output transformers of the amp as that affects things too- sometimes counter to what you might expect.



Yes... Ralph... I will try some of your suggestions.  I have your M60's and have talked with you about upgrades - though, I think mine have the 3.3. upgrades.  I'll try the 16 ohm taps and maybe the 4 ohm taps to see if that makes a difference with the ARC 150se's.  And I'm using Paul's cables, and have his Zeroformers, which I got for your M60's for my Maggies.

But, as you know... the M30.1's and M40.2's have a bit of an emphasis in upper bass / lower mids, which I resolved with some good SS amps (the ones recommended by Harbeth)... but... I think I may prefer the sound of the ARC 150se, except for the bass bloat that is not there with the SS amps.