To those who might be interested, I managed to fix my Monster Turbine Pro Gold which for the third time gave up on me some year ago. I had exactly the same symptoms each and every time after similar usage periods (they would last me a good 6-9 months of heavy daily use and suddenly one earpiece would die). I figured out what the culprit is with these IEMs and totally brought my left earpiece back to life.
Symptoms: One of the earpieces suddenly starts to drop in volume and this will continue until the balance is like 10/90% in volume. Sometimes when the problems start they temporarily disappear only to return back later and stay.
Well, since I heard they didn't manufacture the Turbine's anymore I figured I still had my one time replacement warranty and I wanted my MTPG back. Now I already noticed that the sound from the earpiece did not come from the front, when listening to the backside of the earpiece a lot of the sound came from there. It was leaking sound from the back of my earpiece which my good earpiece didn't. Anyhow I was desperately looking for a method to open the earpiece so I went and tried to remove the protective mesh from the front side. I did this while at the same time playing music through them so I would know whenever I broke them for good (which I was expecting to happen). However, as soon as the mesh came loose from the front .... I couldn't believe it ... sound came from the front again. The earpiece was sealed airtight because the mesh was clogged ... en behind this first mesh is maybe 2mm of space followed by another mesh! Right now my left earpiece is not only working again, it feels like it is even a few percent louder and clearer than my right piece now. I had this exact symptom with sound leaking from the rear side of my earpiece with at least one other pair as well. And when I closely examine the mesh I'm not surprised it is clogging so easily, it's a pretty fine mesh and quite thick plus there's this small space behind it where earwax and such build up.
Here's some pictures of my MTPG:
2 Pictures of the clogged and removed mesh:
Here my fully intact right earpiece: https://www.bronk-ict.nl/Monster3.jpg
And the resurrected left earpiece: https://www.bronk-ict.nl/Monster4.jpg
If you still have your one time replacement warranty and your symptoms match, specifically the one where the sound is leaking out on the rear side, it might be worth a shot for you.
My left earpiece now sounds exactly as it did in the those first few months ... I'd never thought I would be listening music on them again after monster discontinued them.
My right earpiece was out of balance indeed, and with this one I did exactly the same and removed the screen which is fitted loose in the earpiece. With a tiny needle you can get it out by gently moving it in circles in the tiny gap between the screen, by also gently pushing somewhat upward you can lift it out smoothly. Do not apply pressure, you do not want to stick your needle in too deeply. My turbines sound better than ever, very clear!
Edited by DrSkaffa - 1/15/16 at 5:58am