... reference level, which is calibrated at 80db for -20db lufs, so potentially 100db peaks, but usually much lower as I use volume leveling to -20db.
I have no idea how accurate my UMIK-1 is with its calibration file, but
true transient peaks for bass frequencies actually go higher than the expected point when set at your relative reference level. For the most part, extreme peaks probably don't register perceptually as such to the brain as they are quite short/transient in nature anyhows.
I've been doing some tests lately, and even with a
single Rythmik F12 sub (room gain in my case helps a lot) there is actually more room for transient peaks than I expected. Note: I already checked to see if my DAC has enough headroom in case of peaks over 0dBFS, and it's all good.
I read 112dB peak from just a single F12 sub measured at the listening position ~3.5m away -- no speakers -- with speakers ON and overlapping with the sub, transient peak reaches 116dB. Sub was playing cleanly (perceptually) and in no way bottoming out -- I should know as I was sitting right in front of the sub (if both main speakers were playing, those would be the ones to distort more with heavy bass).
Disregarding the test tones/noise, I can still get similar results with extreme high SPL music tracks with corresponding extreme peaks:
L&R S8 SPEAKERS + single F12 SUB - 'Forward' EQ preset
Measured at MLP in couch where speakers are 2m away and sub is 3.5m away.
To be fair, I have a relatively small room...
Oh, and like you, I never listen this loud for more than a few minutes. This was just for testing...