Price Paid:  $80.00 from Etronics.com

Summary:
The fact that noise-canceling headphone reviews were all over the place made figuring out what to buy kind of difficult. I decided to buy the Sennheiser HDC451s ($80), the Sony MDR-NC20s ($120), and the Aiwa HP-CN5 ($50), and the Etymotic ER-6 ($130), try them all, and then return the three I liked least. Bose makes what are probably the industry standard but they weren’t any better reviewed than the others and at $299, I wasn’t interested. Here’s what I found: Comfort: Kind of subjective, but in my opinion they rank as follows: Etymotic, Sony, Aiwa, Sennheiser. The Etymotics are basically earphones built into earplugs, so there’s no bulk to worry about when moving around or trying to sleep on a plane. How comfortable they are kind of depends on how you feel about having things shoved in your ears. Of the conventional ‘phones, the Sony’s closed-ear design is more comfortable over long periods. The open-air design of the other two tends to squeeze your ears after a while. The Sennheiser loses because of an inexplicably uncomfortable pad in the top. Noise Canceling: Etymotic, Sony, Sennheiser, Aiwa. The Etymotics have no noise-canceling circuitry and rely purely on blocking the ear canal to reduce noise. This cuts more noise than the others and does it across the entire spectrum—making it the only one that will silence the kid screaming in the seat behind you. In the conventional ‘phones, the Sony again benefits from the closed-ear design, passively blocking some high register noise that the others miss. The Sennheisers actually have the most elegant electronics, silencing low hums with less hiss than the other two. Remember that active noise canceling only works in the very low registers—like the rumble of an airplane. Sound: Etymotic, Sennheiser, Sony, Aiwa. The Etymotics live up to their reputation of being one the best sounding ‘phones on the market at any price, though they can amplify body noises such as chewing. The Sennheisers sound really muddy with the canceling turned off, but with it on they give fairly crisp sound a bit lacking in bass. The other two remain kind of muddy sounding with somewhat sloppy bass which might make watching movies on a plane a little more difficult. Overall, the Sony and Aiwa don’t sound any better than the cheap ‘phones that came with my MD player. Convenience: Etymotic, Aiwa, Sony, Sennheiser. The Etymotics fit in your shirt pocket but are definitely harder to get in and out than the others and don’t include an airline adapter. The Aiwas fold up quite flat, have the batteries in the headset and have a carrying case. The Sonys fold up (but are still bulky), include a carrying case, and have the battery in the headset. The Sennheisers don’t fold, have no carrying case, and have the batteries in the cord. All three conventional units come with airline adapters. So in conclusion, the Etymotics are pretty much light years ahead of the others, but only if you are okay with having them jammed in your ears (didn’t bother me, but my wife had no interest.) The conventional units all have their pluses and minuses, so you’ll have to decide what features are important to you.

Strengths:
Good noise canceling circuitry Decent sound

Weaknesses:
Unwieldy Uncomfortable

Similar Products Used:
See review

Price Paid:  $99.00 from Crutchfields

Summary:
I purchased the Sennheiser HDC451 Noise Cancelling Headphones primarily for business travel. After reading many reviews on cans of this technology, I selected the Sennheisers based upon cost and past experience with other models in the Sennheiser line. I haven''t read too many reviews on this model, so I thought I should add to the review base based upon my experience. I think that this model originally sold for around $270, but now they sell in a much more reasonable range. I see them now for between $85-150. I paid $99 at Crutchfields and received them promptly for reasonable shipping charges. I bought these first and foremost for the noise-cancelling feature, and in that regard this headset works well. In a car or on a plane, the obtrusive noise level simply disappears. These are open air design, with large, round, flat ear cushions that are very comfortable to wear for extended periods, typical of most Sennheisers. Comfort and light weight are very important attributes in a travel headset. Sleeping with them on poses no problems. The quality of materials and construction of this headset appears to be properly commensurate with its price range. I have no significant complaints in these regards. I have seen reference to Sennheiser having sold these to some airlines, like Bose has with American Airlines. Any headset sold to an airline must be fairly robust given the abuse they receive by the passengers. I can''t say I have ever seen these Sennheisers on any of the domestic carriers, however. The two-year warranty is a comfort as well. These phones are powered by two AA batteries in a small case with the power switch and LED. Although the phones can operate with no power (pass thru), the sound is attenuated in the high frequencies and is very muffled. Only when powered up with the noise cancellation on do the headphones sound decent musically. Do not buy these phones for their audio performance! For $100, there are many other headphones that are far superior to these! These phones lack bass response, and their midrange is somewhat veiled, but not terribly so. The highs are o.k.; they certainly are not harsh sounding at all like so many OEM headsets that come with portable players. So if anything, these phones err on the side of reticence rather than exaggeration, which makes them tolerable.

Strengths:
Comfortable, lightweight, quality construction, excellent noise cancelling in autos or planes, reasonable sound quality, price/performance

Weaknesses:
Poor bass response, slightly veiled midrange (but remember where these will be used!), felt ear pressure when noise cancelling turned on (like you are underwater) but this is similar to reports from other phones of this type. This may bother some people to distraction, so beware!

Similar Products Used:
Bose headset: even more comfortable and better sound (exaggerated bass, though) but very large and difficult to sleep with due to large size.