Sennheiser HD 599 vs Sennheiser HD 598: which to buy?

The Sennheiser HD 598 is my pick here. It takes sound quality, soundstage, comfort and build in this pairing, and the newer model does not claw any of that back.

Buy the HD 599 if weight is the deciding factor. At 250 g it is less than half the mass of the older pair, which matters if you wear headphones all day and notice pressure building up. It is still a comfortable, well-padded open-back with clear, realistic vocals, so podcasts, streams and long gaming sessions suit it well. Two caveats: the supplied 2.5 mm cable is the weak point and mine broke quickly, and the left-right panning is less convincing than I would want for surround work. Budget for a better cord and it settles into a capable everyday headphone.

Everyone else should go for the Sennheiser HD 598. The open-back presentation is the reason: instruments sit in clearly defined places, the sense of space feels closer to a room full of speakers than a pair of drivers, and the bass stays smooth and controlled rather than bloated. Vocals and acoustic material are where it is most convincing. It also runs happily straight from a phone, tablet or computer with no amplifier, and it is the more comfortable of the two over long sessions. The plastic feel is real and it will not block outside noise or stop sound leaking, so keep it for a quiet room. In that setting it is the better listen and the better buy.