These little guys were great... for a while. The total range of sound it brought out of any mix was glorious, and in my life I've never had better sounding IEMs. The PROBLEM was the lifespan. I listen to and write various orchestral scores. None of them played at obnoxiously loud levels, so it confused the crap out of me when suddenly the left driver suddenly... got quiet. The volume of the left monitor slowly but surely lost the ability to play audio as it got quieter and quieter until it finally stopped producing sound altogether - with or without an amplifier. I have never in my entire life had this problem with speakers of any kind, big or small. This took a few months, mind you. But it's almost as if someone turned the volume down and never cared to turn it back up. Could have just been a defective (please explain how this is possible) headset, so I'm not gonna bomb the review, but yeah... wow.