It shows 0dB in normal use because, iirc, you can't store treble/bass/tilt settings.

Every time you turn the speakers on, they will default back to 0dB.

You can store position settings, sub settings, and, I believe, separate/permanent centre tilt offset, if you run a centre speaker.

HC: 861v4/ID40/LPS, DSP5000, DSP5000VC, DSP3100, SW1600, HD621, Oppo BDP-105, Sony VPL-HW55ES
2-Channel: TEAC VRDS-7/Trichord Clock 3/PSU, Avondale S100, Harbeth Compact 7ES-3
Previous Meridian: 5000C, 5200, 7200.2, 6000, 562V.2, 568.2mm, 800v4, 808.2i, 818v2/v3, 861v8, 551, 502