The HD 600 Avantgarde Headphones are audiophile-quality, open dynamic hi-fi/professional stereo headphones. The advanced diaphragm design eliminates standing waves in the diaphragm material. The HD 600 can be connected directly to hi-fi systems of the highest quality, in particular DAT, DVD, MD and CD players. These Sennheiser headphones are an ideal choice for the professional recording engineer recording classical music.