Hi everyone, 

 

I just got from a friend a pair of Beolab Penta. They look great but one of them has some issues. 

Its sound is really lower than the other one and its behaviour is weird. While one turns off automatically when I stop music the other switch on and off regularly. 

I tried to measure impedance in the middle speakers (that don't really moves when there's music) and the impedance looks ok. So all speakers seem to work. 

 

I plug both of them to a preamp with RCA cables. 

 

Thanks for your help.