I have just got my new system for 1 month and it's only started to occur now.

im wondering whether it is a grounding issue or something.

does anyone have any experience?

thanks

I would do a number of tests to identify if this is a speaker thing, cable thing or Moment/pre-amp thing.

First, I don't remember what Mk Powerlink cables the BL5 requires (thick with ferrite coils at the end iirc). Also, the Moment is rj45, so the cabling is unclear.

Try flicking the L/R channels on each BL5 see what that dos. 

Try daisy chaining the cables to see what that does

Try swapping the cables from Moment to BL5 etc....

All thus should hopefully help to locate the source f the problem.

Maybe also worth to test the BL5s in standalone mode. Disconnect PL cable, set BL5s to L.OPT 1 and activate them by selecting an audio source (CD?) oon Beo4.

If this works properly, you know your BL5s are ok. Next step could be to connect another audiomaster - if available... - with "old" Powerlink sockets directly to your BL5s.

I think it could be the rj45 - DIN adapter.

Stefan