Aiwa HP-CN6 Consumer Headphones

Aiwa's HP-CN6 Noise Cancelling Headphones are inexpensive, yet effective active noise cancelling headphones, packaged and designed primarily for travelers. They work well enough that they should be of interest to anyone who occasionally wants to filter out lower mid frequency background noise while listening to music or spoken words. I had been looking for a good price on noise cancelling headphones to use with an mp3 player while mowing the yard. When Amazon offered these for $17.98, I found the price low enough that I felt I could afford to purchase a set for this limited use, and even at the typical street price of $30-$40, these are a fairly good value. (The price and availabilty of these headphones changes a lot on Amazon, consider watching for sales before making a purchase).

Aiwa (part of Sony) provides the following spec's and features for this model:

Up to 70% Noise Reduction
Convenient Folding Design
Open-Air Type
Two prong adapter for In-Flight Use
Carrying Pouch
1/8" X 1/4" adapter included
Noise reduction: 10 dB at 300 Hz, Aiwa claims up to a 70% reduction for sounds in the 40 to 1,500 Hz range
Frequency response: 30 to 15,000 Hz (the Aiwa site says 20 hz to 20,000 hz, but don't believe that, the Amazon listing for these headphones says 30-15000, which is believable, based on the sound quality)
Powered by a single AA battery, over 30 hours battery life
Weight with battery: 5.5 ounces

Note: These headphones appear to be almost identical to Sony's MDR-NC6 noise cancelling headphones, same included accessories, identical spec's, and similar in appearance and model numbers.

How They Work

Both Active and Passive noise cancelling headphones are available. Passive models block noise by sealing off your ears from outside sounds, a low tech solution that can also keep you from hearing sounds you need to hear. Active models actually "cancel" sound, though only in the low frequency range. Aiwa provides the following description of their "active" noise cancelling headphones:

The built-in microphones of the headphones pick up the ambient noise. The noise canceling circuit makes equivalent anti-phase sound to counteract the noise and output this anti-phase wave through driver units. Two waves eliminate each other. The background noise is reduced by more than 10dB (by approximately 70%). This function is effective for noise in the mid frequency range ……. (40 to 1,500 Hz for the HP-CN6), which is a level most irritating to the human ears. What's more, the noise canceling effect does not affect high frequency band sound such as car honks, alarms or humans voices.

The individual earphones on the HP-CN6 are slightly larger than your ears, covered with foam pads, which then fit on top your ears and are held into place with the headband. On the outside of each earpiece is a small microphone which picks up ambient noise. The electronics in these 'phones use that data to cancel out ambient noise. On the right headphone is an on-off switch. In the off position, the headphones work like any other model, with no noise reduction. Turning the switch on kicks in the noise cancelling circuits, effectively reducing outside noise.

The technology really works, turning on the "noise cancelling" switch immediately cuts out half or more of the low frequency sounds you hear. Covering the microphones built into the ear pieces immediately lessens the noise reductions circuits, almost like magic.

How Well do these Noise Cancelling Headphones Work?

I purchased these headphones to listen to my mp3 player while mowing the yard. For this application, the headphones work well. Turning on the headphones while mowing immediately cuts the mower's sound down by a lot, subjectively more than half, I'd judge. I can still hear the mower, but the noise reduction is enough that I now have a hard time using the mower's sound to tell when the mower is overloaded or starting to bog down when I hit a wet patch or heavy thatch in the yard. The noise cancelling circuit also boosts the mp3 player volume a little, equivalent to a 5-10% increase my mp3 player's volume setting. Between the volume boost and the noise reduction I find I can reduce the output of my mp3 player from 100% to about 65% when mowing, a savings sure to save wear and tear on my eardrums. I don't hear any background noise created by the headphones in this application, though, in quieter situations the noise cancellation seems to create a very small amount of background hiss (often referred to as white noise) that you can hear.

If you have a computer with noisy fans, the HP-CN6 will do a terrific job of blocking out the fan noise, almost to where it is unnoticeable. I'd think these would work well blocking fan noise in rooms full of electronic equipment.

If you're looking for protection against the from your neighbor's 1000 watt surround sound system these headphones won't solve your problem. A lot of the low frequency sounds from music and movies will be blocked, but the booming subwoofer will still be a problem, and most of the mid and high ranges won't be blocked. You'll hear less, and what you'll hear will be little tinny, but you'll likely still be bothered.

Noise reduction at this price isn't perfect, sound quality and comfort are lessened, though though the drawbacks are minimal.

Sound quality - More than good enough for my uses, but not great. The frequency response of these headphones is 30-15000, while most standard headphones have a wider frequency response of at least 20-20,000hz or more. I'm not sure how much we can really hear and the high and low end of our hearing ranges, but music does not sound quite as good on these headphones. Music sounds just a bit flat, less bright. Bass response seems fine to me, pretty good actually, but highs seem a little muted.

Comfort and Ease of Use - All of the noise canceling electronics and the battery compartment are built into the headphones themselves, so there's no external power supply or box that you need to clip on your belt, which is really nice. Even with the battery, I don't find the weight of the headphones to be a problem even after a couple of hours.

The folding design of the headphone brackets makes travel with and storage of these headphones easy, but it leads to some compromises. The bracket that connects the two earpieces fits over the top of your head, but not completely securely. If you're not moving, its not a problem, but when I'm moving, this bracket occasionally slips forward or back, requiring an adjustment. There's a hinge in the middle of this bracket, and this hinge presses against the top of your head, and it gives the impression of a fit that's not quite right.

Battery life is excellent. I'm still on my first battery after 3 months, perhaps 20-30 hours of use. Aiwa claims a battery life of 30 hours, but I suspect I'll get better than that. And if the battery goes dead, it only affects the noise cancelling performance, the headphones can still be used as if the noise canceling was turned off.

These headphones seem to play as loud with low power portable audio players (like my Zen Micro) as any of the other headphone's I've tried. I was surprised by this, I had feared that the power requirements of these headphones might limit the maximum volume, but that's not the case.

I'm very pleased with these headphones. They seem sturdy and are reasonably comfortable. Sound quality is good but not great. The HP-CN6's have more than met my noise cancelling expectations. They won't be my first choice for most of my listening needs, but if I'm working in a noisy environment, the tradeoffs I make to reduce background noise are well worth it. The only real problem I've noticed is that these come the same warranty that Sony (which owns Aiwa) offers for most electronics, only 90 days.