The Koss R100s, designed for either home or professional use, are made with audiophile-grade components designed to deepen the bass and brighten the treble. Apparently, Koss' design efforts paid off: the 'phones are rated for an astonishingly wide frequency range of 16 to 22,000 Hz--impressive given how tough it is for headphones to reproduce meaningful deep bass.
The closed ear cups isolate outside noise while soft, circumaural ear cushions help retain low-end frequencies. Oxygen-free-copper voice coils lower density and enhance signal transmission. The extrawide, adjustable headband is padded with vinyl for comfort during long periods of use.
Koss provides a lifetime warranty on parts and labor.
1 Nice sound, but fragile
I bought a pair of these a few months ago, and was quite happy with the quality of sound and the comfort of the headphones.
However, after about three months of use, one of the plastic pieces that connects the ear cup to the headband snapped. Looking at the other side revealed that it was developing a crack in the same place. I could probably get the headphones fixed under warranty, but the cost of shipping to do so would be about half of the value of the headphones themselves. Since it's obviously a design problem -- far too much stress is placed on those flimsy plastic pieces -- I hate to send it back when it seems likely that they'll just break again in another three months. I'll probably find some other set that isn't as likely to fall apart.
It's certainly a shame, because reinforcing that piece probably would only cost them an extra few cents, and would make the product much more durable.
2 Good headpones, but poor customer service from Koss
The headphones sound fine and are comfortable, but the Phase 2 cord that came with mine was shorted out, so the sound only came out one ear. I called Koss customer service, and they told me it could be repaired under the lifetime warranty. They instructed me to send the Phase 2 cord in along with $5 for handling expenses. I also had to pay $3 to ship it to Koss. Two weeks later, I received what I thought was a repaired cord. After testing it I found out that it still had the same problem and there was no note explaining why it hadn't been fixed. When I called Koss and told them what had happened, the lady on the phone tried to tell me that there wasn't a lifetime warranty on these headphones. I told her that I was holding the box and it said that there is a lifetime warranty. At this point she started to get angry with me and in a demeaning tone (as if I were stupid) tells me that I should have sent in the whole headphone set. How was I supposed to know that? The instructions on the box did not say that I had to send everything in. So I spent $8 to have nothing repaired and there's not a chance for refund -- some lifetime warranty.
3 Poorly Made
I have always held a high degree for KOSS equipment, but the earphones that I received (advertised as PRO) are horrible. For one the sound is extremely muddy and almost void of any decent high frequency. Two it seems in this day and age of The Internet and Space Shuttles that man still can't make a pair of headphones that don't short out at the plug! I do have to admit that I gave these headphones a 1 star review, for comfort and they are pretty. ;-P
4 Great for the price!
I had Koss R10, they were pretty good but plasic parts are got broken fast. Since Koss have lifetime warranty I send them back. Now I bought R100's and they are awsome! Sound is great. Bass is deep and clear. Good buy.
5 Good sound and value
First let me say that they are a good value at the current price of about $40. I'm not sure they are worth too much more. That said, I am very happy with the sound quality of these headphones. The one surprise I had was that I could hear artifacts in my MP3s while using these. The artifacts were especially noticeable if I enabled their "surround sound" feature. However, if you disable the surround sound or re-encode your MP3s at a very high bit rate (256 kbps) you should be fine. Not surprisingly, there are no sound quality issues while listening to CDs.
The closed ear design and non-breathable padding make your ears sweat a bit, but it isn't too much of a hassle.
Finally (others have mentioned this too), the documentation is terrible. The only information you get is printed on the back of a card included in the package. It tells you how to enable the surround sound feature, but that is it.
Even with these downsides I still think these are a great value for $40.
6 Good Sound, Awful Documentation
Phase II cord and straight through cord are not thoroughly documented. When I finally realized what was going on, I was able to get great results. Loud rock typically should have the straight through cord. Soft music or classical must use the Phase II cord. Sound from computer games MUST use the straight through cord or else it is so soft as to be almost inaudible.
I wish Koss had invested 25 cents more in a good paid of headphones to give it a user manual.
7 Portable Sound Par Excellence
I tried out several headphones including open air and other earcupped designs. I found the best results with this set. Also with the price that [they are offered] for, I found that this was also the best deal for the sound quality that I was in search of. The two seperate 8 foot cords are both useful. The Phase II cord gave me the best results for use on a home system which provided the extra umph to make the headset sound incredible. The ability to customize the 3D surround sound is a great option and sounds very nice when used on a decent home stereo system. Using the Phase II cord didn't yield the same results on any of the portable CD players that I used. The volume was noticeably lower and the bass quality was substantially decreased as well. Better results were produced using the regular cable for use on portable devices and low-end stereo systems. I received higher sound volumes and better bass response using the regular cable. Lightweight, comfortable, high-quality sound, and low price ..., you can't find a better set of headphones than these.
8 Good clean sound
If Amazon is still selling these phones for $40, snap them up; you are getting an excellent deal. The sound is crisp and clean and full-bodied. The closed earcups let you hear bass far better than open air designs, but even so you will occasionally have to raise the bass level a little bit to compensate for the small headphone speakers. The speakers _are_ large enough to harm your hearing, so be careful with volume levels. I've found that I can listen to music at comfortable levels and almost no sound leaks out of the phones. The isolation provided by the earcups is quite good.
The headphones come with two coiled cables, only one of which is needed to use the phones. This is nice if one cable gets yanked or stepped on. Both cables have a modular headset plug on one end (same as goes into the handset of a telephone) and a mini-plug (walkman style) on the other end. An adaptor is included so you can use the headphones with equipment that requires a 1/4 inch plug. One of the cables has an inline control that lets you invert the phase of the left/right signals and send them to the opposite ear, which yields the "wide stereo" effect that some boom boxes offer. You have complete control over how much or how little of this effect you want, and you can turn the effect completely off.
For reasons unknown the headphones do not have "left" and "right" marked on them, so I'll save you some trouble and tell you that the left earcup is the one the cable will be hanging out of.
The bad things about the product are about what you would expect. The closed earcups are comfortable but will inevitably make your ears sweat. The phase inverter controller is cheap; expect some scraping static as you move the sliders back and forth.
9 Background Noise
I purchased the headphones so I could listen to my radio as I cut the grass. They work very well for this purpose.
It is hard for you to judge the noise reduction from an evaluation but here are some benchmarks. When I use my 3-? hp gas walk behind mower I could not listen to my radio with the headphones that came with the radio. I had to have the volume on max and not only was it uncomfortable to listen to I thought it would be dangerous to my hearing.
When I use my electric walk behind mower (75db, the blade makes a lot of noise) I had the radio about 25% to 33% louder than if the mower was not running. I could listen to the radio but it was a little too loud.
With the new headphones and the electric mower I have the volume at normal or sometimes about 10% higher than normal. I hear the radio clearly and the noise from the lawnmower is about 50% of what it was without the headphones. The radio sound seems to come from the center of the headphones and the outside noise is in the background. I think the quality of the reproduction of sound helps cut down on the background noise.
If you put the headphones on with no radio you can hear the TV or talking in the room without much trouble. However with the radio on the background sounds fade away.
I use the mix cord that comes with the headphones on a radio that is not stereo. Instead of having sound in only one ear the mix control lets me have sound in both ears.
10 Great sound without Phase II Cord
I chose the R100s primarily to use while mowing my lawn on a LOUD and NOISY ride on garden tractor. The R100s sound great, shield the external noise very well, and are very comfortable to wear. I will be using them for much more than just mowing the lawn!
The headphones come with two 8 foot coiled cords that plug into the bottom of the left earcup with a jack similar to those found on telephones. Both cords have 1/8" ("Walkman") jacks, but, the R100s also include a 1/4" adapter for a home stereo. One of the cords has inline 3D mixing device, which Koss calls a Phase II control. I found the cord with the Phase II control reduces the volume of the audio substantially. The documentation provided states that a decrease in the sensitivity when using the Phase II cord is a "normal occurrence." When the normal cord is used the sound is clear and exceptional and the bass response is outstanding.
The headphones are lightweight and are comfortable to wear for extended periods thanks to the extra padding on the headband and multi pivoting earcups. I found I have been able to wear them for 4-6 hours without any discomfort.
