Now I recall a bit of your amp postings...
Tube amps exhibit more distortion as you crank them up, solid state is the opposite, but digital??
I've been a fan of mass loaded transmission lines (MLTL) ever since I fell under the spell of Irving (Bud) Fried in the 70s. By the early 80s I had a 3-way with 8 inch woofer in a 6 cu. ft. MLTL that could do 114 dB at 17 Hz (too much for home, but would make you cry for love of what it sounded like in a 20,000 cu. ft. chapel).
Currently I own the original commissioned brineacoustics FTA-2000 (a conventional MLTL houses a "mighty" Fostex F200A driver with a huge AlNiCo magnet). I've replaced the baffle step/zobel with DEQ and had Bud Purvine himself give the drivers EnABL treatments. These aren't the typical high efficiency but thin sounding Fostex drivers, but are 90 dB/w/m, 8 ohm, 30-20,000 Hz. So bass is fully there but they thrive with the 100 wpc from my Channel Island Audio D-100 monoblocks.