Review: Red Giant A03 and TDK ST750 headphones

If you're wondering what kind of common thread we've found between two such obviously different headphones, stop wondering. They have nothing in common. Except three things:

1) They're both headphones
2) They both employ unusual engineering.
3) They've both been sitting around my office way too long.

With so many manufacturers pitching us headphones, and with me sometimes a little too willing to say "yes," I often end up with a surplus of review samples. So I thought I'd get these two very interesting headphones off my desk, at long last, and onto the pages of Tech^2.

First we have the $149 Red Giant A03 Ossicle, one of only a very few in-ear monitors to use dual dynamic drivers. Each earpiece contains an 8mm "tweeter" and a 14.3mm "woofer." In theory, dual dynamics (which are basically minaturized versions of conventional speaker drivers) should deliver, well, more dynamic sound, with potentially more bass power. We've already seen this in the Fanny Wang WangBuds, but sadly, that headphone's non-sealing silicone tips made it impossible for our panelists to hear what the dual drivers can do.

Next we have the $249 TDK ST750, a fairly conventional over-ear headphone except that it has an internal amplifier. That's not so unusual, because all Bluetooth and noise-cancelling headphones have internal amplifiers. What's unusual is that the ST750 doesn't have Bluetooth or noise cancelling. The amplifier's there purely to improve sound quality. It boosts output by a rated +6 dB, thus eliminating the need for a booster amp if you're using it with, say, the weak headphone amp built into most laptops. It also prevents the output impedance of the source device from affecting the headphone's frequency response.

But as any regular reader of the headphone reviews on knows, unique engineering and advanced technology don't necessarily result in superior performance. So let's run these headphones past our listening panel and my Clio FW audio analyzer to see what they can do.