"A great earbud!"4.5 starson by omahapianist
Pros: Clear, articulate sound throughout frequency range.
Sliding volume control on chord.
Flexible, L-shaped, rubber plug prevents excessive strain on jack when MP3 player is in a tight place.
Cons: Proper fitting within the concha may take some adjustment.
No clip to secure cord to outerwear.
Cord could be longer in some situations.
Summary: Earbud-styled headphones aren't quite as commonplace as they use to be since the advent of in-ear headphones but earbuds are still a wonderful alternative to those (myself included) who don't care much for sticking silicone inside their ear canals. Nevermind the constant removal of earwax and other things to keep them clean, in-ear headphones can be a bit of work to maintain and to fit. Obviously, this may not be the case for everyone but for me, earbuds are the way to go for my portable needs and the Sennheiser MX-660's are truly deserving for those mobile music junkies who want great sound.
Being a hardcore headphone fanatic, I'm particularly fussy about how I listen to music. At the heart of it, I use Grado headphones (SR-325, SR-125, iGrados) because their sound is simply indescribable. Warm, detailed, rich, and clear. With that background in mind, I have also used a number of Sennheiser products as well (HD-595, other models as well) and I, like many others, recognize that these cans have their own sonic signature, which is usually described as laid back and less-forward than the "in-your-face" Grados. It's a sound that, like the Grados, you either love or hate. With the MX-660's, it's a sound you'll love with its' clear highs, full-bodied mids, and articulate, dynamic bass. These buds are also quite revealing of the source as well. Well-recorded music will shimmer with delicious, ear-bathing sonics. You will also hear how poor poorly-recorded music is as well but it's still very listenable. I use these primarily for my smart phone and Zune 80 but when plugged into my laptop, it yields an even richer sound. I also have a dedicated headphone amp and when the Senn's are plugged directly into that device (with a 1/4 inch adapter), the sound is simply amazing but you really don't need an amp to achieve a satisfactory sound with these buds. In fact, the sonic difference between a portable device or PC can be slight in most cases, which is a good thing because you want great sound from all your sources. Keep in mind, these buds sit within the concha of the lower ear so they do not block out external sounds. They weren't designed to do that so if blocking outside noise is your priority, there are many other 'phones on the market for that purpose.
Also, having read a number of comments about the MX-660's and other similar buds having a lack of bass, I'm here to tell you that this is the greatest source of misinformation for accurate audio reproduction. Back in the early days of portable audio, bass reproduction was, in a word, lacking. To compensate for this, manufacturers created earphones with various bass-enhancing circuitry which did nothing more than blow-up the lower midrange frequencies giving listeners a false sense of "bass". This was nothing more than sonic mud as it did nothing but smear mid-range detail with bloat and boom. Unfortunately, many listeners accepted this as true bass so when higher-quality earphones appeared on the market, some listeners became disenchanted with them claiming a "lack of bass". This attitude is gradually changing as some people are beginning to realize that TRUE bass does not bloat, boom, or smear the details of the music which are mostly centered in the upper mid-range/lower high frequencies. With that said, the MX-660 produces great bass, especially if fitted properly, without obscuring the musical detail. Granted, there are other bud/in-ear 'phones that can do a slightly better job of preserving the detail of the music with a better balance of the frequency extremes than the MX-660's but you will definitely pay more for that privilege - sometimes 3 to 4 times as much. However, for the price of these Senn's (under $50.00), I believe you'll find these buds more than satisfactory. Highly recommended!