Sennheiser RS-180 headphones disassembled

RS-180 are great but they have one feature that I don't like. The tend to get to warm.
The temperature inside the ear cups is about 5 C degrees warmer than outside. For me that's too much.

So I opened the headphones to see if there's any improvements to be made. At first I thought it was the electronics warming the speakers but there's only electronics in the right ear cup.

 Without the muffs.

Four simple screws to open and you get the speakers out. This is the right ear cup with the Kleer electronics.

The left ear cup is almost empty, only speaker and battery inside.