I’ve had 6Ks twice. First time bass was overwhelming, second time it was all perfect. Same room. Tweeters and re-cap on the second pair - makes a huge difference on 6Ks as they tend to be quite old by now… Also periodically carefully re-tighten bass drivers - nothing crazy, just nip them up to make sure they’re not loose.

Also important to position well in the room. The second time I played a little more and found more of a sweet spot.

HC: 861v4/ID40/LPS, DSP5000, DSP5000VC, DSP3100, SW1600, HD621, Oppo BDP-105, Sony VPL-HW55ES
2-Channel: Oppo BDP-105, TEAC VRDS-7/Trichord Clock 3/PSU, 551, Quad 303, Harbeth Compact 7ES-3, Kimber cables, Russ Andrews mains and supports.
Previous Meridian: 5000C, 5200SL, 7200.2, 6000, 562V.2, 568.2mm, 800v4, 808.2i, 818v2/v3, 861v8, 502