System, speakers or both? I agree, with the caveat that it may not be the entire system but it could be. Typically I think though that it's typically only a component or two. It might be an amplifier, preamplifier or speaker issue. I've noticed in recent years that while listening to someone's new speakers or auditioning them in a store or elsewhere that often I'll be thinking that it sounds okay and then they'll crank it up and say listen to that! Now they're sounding more impressive. Often times these are expensive speakers played through high end systems that, IMO at least, should sound great at any level, not only on loud! I've begun evaluating speakers for my own use at low levels and if they don't pass that test, there's no point in going on to the "crank it up" stage for me. This is an interesting thread, sorry I can't tell you what levels I listen at either at low or high levels as I have no meters to measure it. I do tend to turn it up pretty loud when I'm alone or with someone with similar musical interests, be it SRV, Dire Straits, Diana Krall, Nora Jones or Frank Zappa, in addition to low level listening, often late at night when my wife's in bed.