Got similar story and think that good speaker cables could improve your bass freq. Used to have the Krell 300i but now replaced with the Atma Sphere MA1 Mk3. Even with the MA1 power, the bass still lack of impact/realism. After testing so many bi-wire product, currently, very happy with Anticable for the HF and the Canare Quad for the LF. On the subject of Proac's bass capability, when the Proac Response 3 is paired with the AudioValve Challenger 115 and Tungsol 6550, I've experienced the most realistic bass ever i.e. growl, impact, pressure... Btw, systems owned include Joule, Shindo, but most realistic bass come from this combination Audiovalve + Proac...