The new HiFiMan HE-400 headphones are equipped with some of the best sound technology out there, and this $350 pre-order makes them on of the sweetest deals in audio gear.

These HiFiMan cans are the least expensive planar magnetic headphones we've ever seen. Planar magnetic drivers aren't new tech, but they aren't widely used despite their excellent sound. (Here's a good explainer on the details of how they work.) Most headphones use dynamic drivers, which are cheaper and easier to produce. Planar magnetic drivers use a very thin, lightweight diaphragm that's surrounded by strong magnets. Compared to dynamic drivers these headphones use more force and more surface area produce sound. The result is a very responsive headphone that's more accurate, with better low-end response and less distortion than your average dynamic driver.

Unfortunately, planar magnetic headphones range in price from very expensive to unbelievably expensive. So expensive, in fact, that the $400 price tag on the HE-400s looks unbeatable. If the HE-400s are the real deal they might be the smartest splurge you make in a long time. The HE-400s don't ship until mid month, but if you pre-order them by January 13th, HiFiMan will knock $50 off. [Head Direct via Head-Fi]