Loose fitting models like the Klipsch in-ear models are easier to insert. That’s partly due to the nature of the seal and partly because active noise cancelling headphones like the Audio-Technicas tend to be bigger and thus are slightly more challenging to align. The ANC23s aren’t particularly hard to insert, but they’re not the easiest either.
There is a secondary benefit of the electronic noise cancellation approach. One is that the bass performance of these headphones should be somewhat less dependent on the exact seal one achieves when inserting the earpieces into the ear canal. (I discussed this same point when I reviewed the Phiaton PS 20 NC in-ear noise cancelling ‘phones.).The Audio-Technicas do a better job of demonstrating this aspect of active noise cancellation than the Phiatons did, and as we’ll see in a moment, the ANC23 has pretty potent bass.
I found the noise reduction from the active circuitry to be impressive. At least for midrange and high frequency noise, the ANC23 gives the effect of wiping out the background noise and replacing it with very low-level hiss. You switch on the noise cancelling circuitry, and bang, the noise is almost gone. With more impulsive sounds like tapping, some sound still comes through, so the circuitry isn’t as effective if your problem is talkative office mates.
I did find that the ANC23 has one minor noise irritant. When the cables rub on your shirt, the sound is (mechanically) transmitted through the cables to the earpieces, and then to your ears. I wish the cables were a little more flexible to avoid this. I also need to mention that the cables are rather short for desktop/tray table use. Note, too, that the volume control markings are embossed in the black plastic case for the noise reduction circuitry, which makes reading the labels difficult.
I tested the ANC23s using an iPhone 4 loaded with tracks ripped from CD in Apple Lossless format, driving the Audio-Technicas both directly from the iPhone and via a NuForce Icon DAC/amplifier.
The ANC23s are really quite likeable. They sound impressively good, especially given their reasonable price, though their sound isn’t strictly aimed at maximum accuracy. But most people would like a small amount of “tonal tweaking” in their headphones, and I think the ANC23s’ tweaks have broad appeal.
A key point that many will view favorably is that the ANC23s have pretty solid bass. I’d rate them as slightly elevated in the mid-bass, with the note that this elevation in level doesn’t seem excessive or particularly intrusive. In fact, I think many people would view a headphone with less bass as sounding “wrong.” That’s because listeners aren’t necessarily looking for headphones that sound “just like live music,” but rather looking for headphones that, on an intuitive level, sound natural and well balanced. Lots of folks also like slightly elevated bass on headphones to help compensate for the lack of bass “air” (that is, the sense of large bass pressure waves pressing against our chest cavities, and so on), which necessarily gets lost when listening through headphones.
From around 200 Hz to 5kHz the ANC23s roll off very slightly. This is another well-consider choice, I suspect, since some people prefer a “rich” and not at all strident sound in the midrange. People who love instrumental and vocal dynamics, however, might find the ANC23s a little reserved or dull.
Above this band the Audio-Technicas seem to offer flat response, though this means highs may sound a bit subdued, since treble response is geared to blend smoothly with the headphone’s upper midrange, which is somewhat reduced in level to begin with. The result, however, is a smooth sound. Cymbals and other high frequency instruments are presented with admirable detail, though you may sense, as I did, that mid and upper treble frequencies could do to have a bit more energy. But experienced listeners may feel that such extra energy carries a price (in terms of potential upper midrange/treble glare)—a price the ANC23s avoid extracting.
Because of their active noise reduction circuitry, the ANC23s are also above average it terms of resolving low-level details. This is important for a sense the acoustic environment as well as for articulating the particular beauty of certain instruments.
I think the frequency response tailoring of the ANC23s will work extremely well as a package for a large group of listeners. If you are one of those, I think the one place you might perceive that the ANC23s come up short is in midrange refinement. Some headphones, including the Phiaton PS 20s I tested recently, just give the subliminal sense that they have lower distortion. The good news here is that the Audio-Technica’s midrange issues are subliminal “sins of omission” and not really front and center.