running harbeths and tubes as well. i have tamed bass quantity and peak issues with the following-
1 modify speaker position- away from all walls, screens, cabinets and surfaces as much as possible, min 2 feet all directions.
2 stands- open frame stand with harder dots. soft dots between speaker and stands cause bloat. use clear silicone bumpers.
3 tubes- different small signal tubes will help drastically with bass bloat. new production and nos tubes seem to be bass heavy, e.g. eh, jj,, brimar. try some mazda or amperex, amperex off label.
4 cables, interconnects- different cables tend to be bass heavy. try van den hul, nordost, audience for less bass bloat.
all of the above can add together and should be optimized individually. when you have done your best i doubt you will need DSP.
