I exchanged the logicboard and now the speakers don't work well.
If plugged in both on the logicboard then the right speaker (the one without the subwoofer) makes distorted sounds.
If I plug out the other speaker then the right speaker sounds good!!!
Left speaker plug in only: no Sound at all.
I checked the restistance. It is similar on both speakers. Between 1 and 2 pin it is 5 ohm and between 3 and 4 it is 10 ohm. So apparently, all is fine with th speakers itself.
I also tried to reset PRAM and SMC.