Caused distortion when running a mono mike through it.
583842
I actually bought this product a few years back, hoping to record some instructional videos on my laptop. When I would record voice, however, that was a noticeable distortion on the recording. I tested the same external mike using the built-in plug on the laptop and that worked fine (with no distortion). So I quickly threw this into a drawer and never used it again until recently. (I had my reasons at the time for wanting to use this product instead of the built in plug.)

So here, several years later, I bought a new laptop that has a single smartphone type jack for the microphone and headset. Since I again wanted to to use my single (TS) mono external mike, I gave this another try. This time, I could get no signal at all from my external mike into my Samsung ATIV Book 9 laptop (although the adapter was recognized by the Win8 OS).

I avoid writing (or reading) one-star reviews... but I'm tempted with this one.

So once again, this adapter proved useless. I guess I should just toss it out... but instead I'll toss it back into the drawer. (Hope triumphs over experience.)
4025276
I use it as my main microphone for gaming voice chat. It works and the range on this is huge, other people can hear me when its 4 feet away, but when it's attached to the collar of my shirt, its not too loud for them. No distortion when the mic is at normal range. If you are 'eating' your mic, then yes it will be distortion, though I'd not see the possible unless the user was really trying to blow their opponent's ears out (which I don't condone).
3751237
These sound great, and they look great but still get distorted.  Im not sure if that distortion has anything to do with my subs, but they distort anyway
3423664
These seemed like a good alternative to, say, the Roland CS-10EM. A cheaper way to achieve decent binaural recordings. And when they worked, they pulled that off. Sound was a little hissy, but to be expected, and other than that it was clear and directional. But, as I moved my head I could hear sound popping in and out of one earbud or the other. I thought it was due to them being plugged to both the in and out of the same recorder (the zoom H5) but it still happened when using only as mics or headphones.
This kind of sound was indicative of a short circuit, and if moving your head causes the mics/headphones to sort out, they are not suitable for binaural recordings (aside from being obviously defective).

Shame. O guess you get what you pay for. Sent them back, and I'm now waiting to test out the more expensive Roland's.
3939272
Audio had a lot of static/noise in it when using a single input. Had it at a shoot and it was unusable.
3072831
The "crystal clear high notes" become actually distorted. Maybe mine got dropped on the way to me, but it's not clear at all. The distortion sounds like something is lose inside.
The bass is only slightly more than my laptop.
2350616
Heavily over-modulated recording, to the point where I couldn't hear it clearly at any volume level.
2026919
When using the cable, there was much static through the speakers when the 3.5 jack was wiggled.  We sent the cable back and purchased another
569575
I was trying to eliminate florescent light hum picked up through wireless mic, but it was MUSH worse when mic was run through Rolls HE18. I haven't tried running through audio outputs yet.
4626485
MIcrophone was distorted so much that my friends I play online with asked me to turn off the mic.  Feedback loop kept getting louder and louder.  Playing with settings and trying to optimize through software did not work. Returned.
3607984
After 3 weeks of testing and research I figured out what the problem was. It appears that graphic cards use a fair amount of power and causes a lot of electrical inference. When this interference hits a pair of amped speakers the inference gets magnified and then gets projected as undesirable noises.  This noise would instantly go away whenever I exited a graphic game and would start back up when I reentered the game.  I had to buy a Dual XLR sound card (not cheap) and 2x XLR -> XLR cables to get rid of the inferences.

If you just plan to listen and create music without playing games this cord should work for you. This cord is not at fault, rather all 3.5mm plugs are inherently flawed to pick up interference.  You wouldn't normally hear the 3.5mm inference on cheap desktop speakers or headphones because they aren't amped enough.
4608225
Bought this as a possible solution for recording loud concerts based on the review here.

The built in microphones on smartphones are engineered towards normal speaking voice noise levels.  When you try to use your built in smartphone microphone to record louder sounds (like live music), the result is usually a recording plagued by horrendous levels of distortion (please see the multitudes of live concert smartphone recordings over at youtube for examples).

This microphone seems to be geared towards providing a HOTTER signal than a smartphone's built in mic.  In other words, it makes the distortion problem worse.  Even with the highest level of gain reduction on my recording app, levels still went far into the red.  To be very fair, the product description strongly hints at this by saying it is more sensitive.

I tested the Monoprice mic, the built in mic on my Moto G and a home-built version of the Bootlegmic, recording the same section of music at live music levels, 2 feet away from the speakers.  The Bootlegmic faired best (with -14db gain reduction), followed by the built in smartphone mic (which distorted even when not showing overload in the app).  The Monoprice mic came in last.  It just wasn't possible to reduce gain on the mic (my app maxes out at -20db) enough to keep it from overloading.

So, if your goal is to record loud live music or sounds, this mic is not for you.  However, if you are looking for GREATER sensitivity to record conversations, meetings, field recordings - you can't go wrong with this mic.  It is well constructed and has pretty good frequency response.
1652589
Could not get the gain adjustments to work with my Windows 7 computer. Sound was over-amp'ed and distorted. Fortunately I had a Windows XP machine lying around, which seems to be processing the tapes fine.
1980748
I used this with intent to replace a t50rp cable.

Initially, I was disappointed with this cable as the sound was distorted when I connected the right angled end to my headphones and the straight end to my amp. I then swapped ends and realized the source of the distortion was that the right angled end could not properly connect to the headphone due to the the silver/gray casing cover too much of the connector. When comparing both ends to eachother, the right angled casing covered about a mm more of the connector than than the straight end. I was able to fix the distortion issue by grinding away a bit of the casing with a dremel, but i'm pretty sure that voids my warranty.

So overall it's ok. Just might want to tighten up quality control on the casing so they're of even lengths.
2589700
Update: Per Zeskit's response below, do NOT use this extender with headphones that have an inline mic. That's apparently the problem I had. They were kind enough to refund the cable though, so perhaps I'll find another use for it someday, on a mic-less headset.

It gets points for build quality - you could probably roll over it with an office chair quite a few times and it'd be just fine. In fact, it's so sturdy that the cabling is pretty stiff.
The main problem I have with it is that it sounds terrible. I played a song using headphones plugged directly into this extension, and played the same song with another brand's extender, and also played the song normally. The Zeskit extension made the sound incredibly muddy - ridiculously high mids and bass but barely any treble. I don't know how a simple extender is messing up the tone so badly, but I won't be using this one anymore.
2745004
Output sound was humming. Input to mic sound was strong
1137427
I get nothing but interference when using this mic and UHF is supposed to be less prone to interference. It constantly crackles and distorts and breaks up during my performances. This is in multiple locations (I do school show assemblies all over the east coast) so it can't be due to one cause.