Without comparison but I can classify the sound bad, so compared to other headsets:
Compared to an older closed (and very reasonable) nameless Philips Headphones: The Philips sounds zugesoßt, dull, clearly very flat sound.
Compared to a Koss Porta Pro: The Porta Pro is duller, less detailed, such as behind a velvet curtain (but much better than the cheap Philips). The overemphasized depths of Porta cover anything the rest of the sound.
Compared to a Sennheiser PXC 350: The PXC350 is also behind a curtain, but a less thick. Not so airy, clear and concise as the HD598. Although the PXC already sounds more detail in relation to the Koss. The HD598 sounds simple and complete "natural".
Depth short strokes with airy lighter harp music are clearly independent in HD, the PXC they cover something the rest, the Porta they dominate, at Philips she looked flattened. Reading voices act as the HD listen directly, the PXC listen as in a small, dim room, the Porta as through a thick curtain listen, when Philips introduced somehow dull.
I was a little surprised. Vollenweider, Nigel Kennedy or Alan Parsons Project (Tales of ..) listen to surprisingly complete at the Tender in the sound remains the same even when other sounds strong.