Hi all B&O experts,

I have a very strange problem.

Here's my setup:

• Avant 55
• Beolab 11 subwoofer
• Beolab 12-2 front speakers
• Beolab 6000 rear speakers (detail the speaker cabels are linked so both speakers come together in one PL connection)  
• Beolab 4 ceiling speakers  

Sometimes when I select a speaker role with the beolab 6000 involved they make a soft siss and as a consequence no musical output. At one point I even thought the Beolab 6000 broke down so I replaced them with a second hand pair. However after a while the same issue started again. What makes this even worse is that I can't reproduce it. It just happens sometimes.

I tried all the following:

• I tried replacing the PL port for the beolab 6000 on the Avant
• I rescanned the soundconnections
• I completely shutdown the power for speakers and tv

This is the workaround I use with the highest success rate:

I made a music role with only the rear speakers and when it happens I select this role. I increase the volume real high (in the beginning this was around 70 but it seems as this barrier increases overtime so now's it's the maximum). Then after a while it comes alive full volume, you can imagine that this is not very pleasant way for me (and neighbours). 

None seems to be the structural solution, please help ...🤔