Surround Sound in Your Fingers

At every trade show, there's one product everyone says you have to see. The gadget that kept coming up at last month's AES conference was the Core Sound TetraMic.

This tiny microphone contains four capsules arranged in a tetrahedral pattern to pick up sound in the Ambisonic format. Basically, the mics together encode front-back, left-right, up-down, and level information that can later be presented in a variety of ways. According to Ambisonic.net, the technique produces a 3D audio image—including elevation information—that's "largely unaffected by listener position." In other words, with just four speakers, you hear a true surround recording, and there's no sweet spot. The four channels can also be decoded into conventional two-channel, 5.1-channel, 7.1-channel, and other speaker systems.

Before now, Ambisonic mics cost thousands of dollars. Core Sound expects to sell the Tetra Mic for less than $1,000. But the other breakthough is that when paired with Core Sound's 4Mic analog-to-digital converter (also under $1,000), the TetraMic can record the Ambisonics information to a standard two-channel flash-RAM recorder like the M-Audio MicroTrack. So for about $2K, you'll soon be able to carry a versatile, handheld surround recorder in your fingertips.