Hi! I've been reading this forum for a while and I decided to register I'm looking for a pair of Superlux headphones for "studio" purposes. I've been thinking about HD660, 662F and 668F. Right now I own a pair of 668b and I'm very pleased with them but I want something more "realistic" in the low and low mid frequencies. When I first started tu use this headphones I used to crank the bass and low mid in guitars because it felt like there still was space for those frequencies. When I later listened it on studio monitors or normal hifi there clearly was too much of those frequencies and everything was muddy. Any Info welcomed. Cheers!