Liveried in a slick deep gold-grey and gloss black look, these cans are largely the same headphones as the HD600 with a few quite noteworthy improvements. First and foremost, Sennheiser has improved the baffling damper for tighter acoustic control, and boy did that work nicely! The measurements of these headphones are as close to perfect as we’ve seen, and the sound is probably as close to perfectly neutral as we’ve heard from Sennheiser. The traditional Sennheiser sonic 'warmth' has been coupled to a clarity of detail in the HD650 that is hard to beat by most other reference-grade headphones. Design-wise, the earcup grilles on the outside of the earpieces have been made sturdier; those who have suffered a dented housing on their HD600’s will likely be appreciative. A new velour headband pad design improves on the already legendary comfort of the HD650 headphones, and a slightly tighter tension on the earcup adjusters makes for a more secure fit. The HD650 cord has also been much-improved with a thicker OFC cable design terminated to a full-sized 1/4" plug. A short cable-style adapter to a 1/8" (3.5mm) mini-plug jack is handily included in the HD650 package. We definitely more than recommend these headphones: We say shell out big & cry once, but forever have world-class audio at your ears!
Though the HD650's re-designed Sennheiser cable is certainly better than the original stock cable, we continue to VERY highly recommend the Cardas Audio upgrade cable for truly ultimate detail resolution, musical texture, instrument separation and soundstage clarity. The significant audio benefits of the Cardas Audio cable upgrade will be especially evident with reference quality high-end audio sources.