I will simply say that I have not yet found the "perfect" speaker or one that is absolutely best with all types of music. I wish I could, it would save me a lot of time, money and aggravation.Sound Labs are great with everything I've thrown at them. So are the Classic Audio Loudspeakers. Those two speakers have very different amplifier requirements! I have a set of KLH model Nineteens in my bedroom and they seem to handle all genres as well as long as I don't play them too loud :) But the amp I play them with only makes about 5 watts (although the sub amp can make 1400...) so no worries.
So in those cases that's cocktail lounge jazz, rock, downtempo 80s pop, shoegaze, ambient, disco, classical, ethnic folk, bluegrass, spoken word, punk, death metal, speed metal, medieval, polyphony, new age, gothic metal, techno, gothic punk, 70s prog rock, big band, electro, electronic music, freeform jazz, fusion, acid folk and really, I can go on and on.
These very different speakers can do all that no worries. If you have a speaker that doesn't, I'd like to know what it is! I bought those KLH Model Nineteens on ebay for about $60.00.... although the Golden Ear Subx cost a bit more...