Just want to share this small DYI effort with others who are in similar needs as I am regarding wireless sound.
I was looking for a BT APTX headset with nice sound quality for quite a long time. Tried different over and on-ear options and realised I also need in-ear one with sound signature similar to my IE8 (it suites workouts very nicely). Basically I figured I need just a bloetooth module compatible with IE8 (my wallet was unhappy with another possible round of trying different in-ear items). Quick search for available devices brought no results, and I decided to modify some existing to fit my needs.
My choice was Bluedio S2 Bluetooth sports headset (mainly because I already had it). It's cheap, supports everything I wanted (BT 4.0 and APT-X) and is very compact and light-weighted.
Soundwise the device does not impress, lack of bass, details, pretty much everything is disappointing, except feeling that the main bottle neck is in it's earpieces.
So, I bought spare cable for IE8 on ebay and prepared to merge them together:
After cutting the earpieces and connectors it turned out the wiring is very thin on both so I thought soldering them would be better then just twisting.
In order to seal the connections properly, I first dipped them into glue, to make basic insulation )), then after drying with heatgun covered with heat shrink wraps. In order to keep the joints from unwanted bending I also inserted short 0.5mm wires into wraps before heating them, so that those parts became more rigid.
This is what I've got in the end. IE8 with BT 4.0 and APT-X
This is what was used:
When I started listening I was so surprised of how great is electronics in that Bluedio S2 (for $27) and how crappy were their earphones. The thing now sounds just like Sansa Clip when I plug IE8 there.
I tried many other things before going with this and only Sony MDR 1 RBT MkII sounds better, others like Harman Kardon BT Premium Over-Ear Headphones , UE 9000, Denon Ah-NCW500 are behind.
I would encourage trying this, and in case anyone finds better BT receivers suitable for the job, I would appreciate sharing it with me.