Why You Can Trust CNET Koss Porta Pro KTC review: Koss Porta Pro KTC
The Koss Porta Pro KTC headphones are lightweight physically but not in performance, and they have a convenient Apple inline remote.
The Koss Porta Pro KTC headphones are, as implied by the name, very much street wear, but we doubt whether anyone would consider them as being all that stylish. Instead, these spidery affairs are quite utilitarian, but also quite affordable. They are a variation on the Koss Porta Pro 1, which are AU$40 lower in cost, but lose the iPod remote control. If you're using a non-Apple music player, you might as well save the money.
Koss Porta Pro KTC
The Good
The Bad
The Bottom Line
They come with a soft carry case, and the earpieces fold quite compactly into the narrow metal band so that they can fit inside. The cable is fixed, and it separates into two below your chin for connecting to both earpieces. The left-hand one carries the aforementioned remote control, which doubles as a microphone, primarily for use with an iPhone. No 3.5mm to 6.5mm adapter plug is provided.
We love the concept of the remote (an iPod Touch or iPhone takes too many steps to pause playback), but I found it harder to master this one than similar models. That's because the control buttons all felt the same. The play/pause/multipurpose key was situated in the middle, between the up and down volume keys, as seems to be the norm. But estimating the middle position of a 4-centimetre control is surprisingly hard. Yet, just as we were about to give up after eight or 10 hours of use, we suddenly seemed to master it. Still, keys that feel different to the fingers would be preferable.
The headphones were quite comfortable to wear. They are "on-ear" types, but the pressure is not strong. The headband is a thin, unpadded metal strip, which ought to be uncomfortable, especially to one challenged in the hair follicle department. But the headphones were actually quite comfortable, and despite the low pressure, they held on quite well to head movements. I put this down to their very low weight: just 67 grams, including the cable.
There are pads that sat near our temples, and these had adjustments labelled from "Light" to "Firm". These "temporal" pads were useless on my head, which I like to think isn't too misshapen, because regardless of the setting or the adjustment of the headphones, these pads didn't actually touch my temples.
Performance
Switching between this and some other street headphones, it was clear that the Koss Porta Pro KTC headphones were noticeably lower in output for a given volume setting. This would be due to a modestly high impedance (higher impedance means lower current for a given voltage output, which means a proportionately lower power output) and a slightly lower sensitivity. On the specifications Koss gives (101dB/mW and 60 ohms impedance), they should top out on a typical iPod Touch or Nano (which produce around 1 volt maximum) at about 113dB. If you're determined to do damage to your ears, then these probably aren't the headphones for that.
But if you want to listen to high, clean volumes, they you won't be disappointed with these headphones. Whether it was because they constituted a slightly easier load on the output of an iPod, or because of the open design, they went plenty loud enough, and while doing so retained a beautifully clean character to the sound, avoiding any sense of muddling.
We're inclined to think that it's the open design. Since they don't have to compress air behind the small drivers as they move back, or rarefy it they move forward, they presumably had an easier job of it (note that the driver suspensions are designed with the end use in mind, so they'd have a stiffer suspension than those designed for sealed headphones).
Whatever the reason, they did a particularly good job with recordings that manage the trick of being both busy, yet cleanly recorded. Primus Recordings, for example, in which each drum stroke was delivered with precision, had no sense of dynamic compression and no additional noise generated by the headphones.
Tonally, they were very well balanced and tended for that reason to sound unremarkable. The bass was full and extended, but well controlled. One podcast that we listened to with these headphones had some spurious noise: a strange kind of rumble sitting underneath the voices for its length, which was all too apparent. A quick examination of the source file revealed that this noise was in the 30 to 40 hertz range, which is right at the bottom for almost all music (some synth and pipe organs excepted).
Meanwhile, the midrange and upper frequencies were smooth and well balanced. Nick Cave's voice was clean without that peaky zing, threatening sibilance, that afflicts many headphones.
And with less forthright music, there was a pleasant airiness in the sound, as though the source of the sound was at some distance instead of pressed against your ears.
Overall
Add all that to the low price of under AU$130 and the Koss lifetime warranty, and the Koss Porta Pro KTC headphones are an excellent buy
.