The same thing with me - rock music (practicing in 4x4m room - real drums, 3x >100W guitar/bass amps, years ago). Right ear...and even wax problems now. 
Friend of my has explosion-induced hearing loss (right ear, again) - and you can only imagine our conversation in the bar with loud music. 
About stepped attenuators - yes, they are too expensive, IMO, even if you DIY with "Elna" switches... I have two monoblocs with "ordinary" pots - I just adjust them "by ear", but with simple measurements in a few "favorite" positions I checked the L&R volume...good enough for me.
But stepped attenuators in 2dB steps are really something else. 