x RELIC x
Headphoneus Supremus
Well, I gave a caution, an answer, and a suggestion. The focus ended up only on the caution for whatever reason. Again, if the volume is at max and the m-100 is too quiet then either the source isn't up to snuff or the listener is deaf, or going deaf. If we were to presume the former then trying to listen with different source gear is the immediate answer. If the m-100 are still too quiet with multiple sources and multiple users testing the same pair then it may be time to check the headphone out for issues. If possible download a volume meter smartphone app and measure at the earcups for an average reading. This isn't the most accurate way to test but it'll get within a ballpark. If listening above 95db average for extended periods then a caution is warranted. I listen at around 80-85db average and never really get much ear fatigue.