Photos: Ears-on with the AKG K 701 headphones

Anyone familiar with Sennheiser's flagship headphones, the HD 650s, will know they're a truly stunning pair of open-back cans for reference and home listening. And we love them with the flaming passion of a thousand burning nymphomaniacs.

But the vixen of the open-back headphone world has some competition in the Crave house: AKG's K 701 -- a pair of similarly priced open-back reference-class headphones. With both priced at roughly £180, some informed decisions will need to be made.

After about 100 hours of burn-in time we're happy to discuss some first impressions of these moist-making headphones. Firstly, design. The 701s are extremely comfortable, with a slightly less tight fit to the head compared to the Sennheiser alternative. And the well-padded earcups are encased in cloth, meaning you're less prone to sweaty ears.

Inside are decent specs too: a frequency response of 10Hz-39kHz, impedance of 62 ohms, a rated sensitivity of 105dB/mW, and a maximum power input of 200mW. The foil diaphragm is dual-layered, hopefully deliverying a more impressive transient response than usual.

Listening to music through these headphones is such a pleasure. It's like there's a party in our ears and everyone's making out with supermodels. Every frequency is extremely balanced, with an impressively tight low end, remarkably punchy and powerful mids, and a shimmering high end that doesn't sound harsh or brittle.

Headphones often seem more suited to some types of music and less to others. But the 701s, at least so far, are proving themselves to be great all-rounders for all genres, from rock and metal to dance and pop, to classical and easy listening.

It's early days to be making objective conclusions, but A/B comparisons initially showed the Sennheiser HD 650s to have a noticeably more powerful sound and moderately increased emphasis on bass and the lower mid-range, delivering a slightly warmer, less flat sound. We probably prefer the HD 650s sound, but the differences are subtle and both pairs are equally admirable performers.

Expect a full review soon, where we'll go into much greater detail. Until then do click through for some up-close and personal shots highlighting the physical aspects of these initially impressive headphones. -Nate Lanxon

Each drive unit is encased in a plastic enclosure, with aluminium backs.

The aluminium backs are perforated to give the drivers access to more air.

These cloth-covered earcups are reasonably comfy for long periods, but softer padding can be found on other models.

That'll be the real leather head support. Vegans may want to stick to reference headphones that use less cow in their construction. But at least the cows are being used in great headphones. If we were dead cows, we'd take comfort from this.

The 6.3mm plug is gold-plated and comes with a gold-plated adaptor for adding compatibility with 3.5mm headphone sockets, like those found on iPods.

Cabling is good too. It's a lengthy 3m bi-wired, oxygen-free cable, encased in a rubbery enclosure that doesn't seem to be prone to tangling.

Our camera specialist Rich Trenholm -- our very own Gordon Freeman -- models the 701s with such skill. Just look at him go!

Finally, some comparisons with other headphones (sadly our Sennheiser HD 650s weren't around for this shot). From left to right: Audio Technica ATH-A900, AKG K 701, Denon AH-D5000.