Welcome to Beoworld.  If it was other speakers attached I'd say change cables but as it's the Avants own speakers that have a fault (as they should not buzz), then first step is to get the dealer you got it from to sort it out under warranty.

Dave.

Hi Pavia,

Do you still have this problem?

Cheers

-geoff

Hi Geoff 

Yes i still have the buzz problem

Kristian Rasmusen from Struer will come and look at it tomorrow (28-01-2015). 

Kind regards and thanks

Pavia 

It's sorted now :) 

B&O came today and got it to work without the buzz.

Got a new one. They said that it might be a cable that had moved doing transport or otherwise. 

They took the old tv back to the lab to be sure of there presumption. 

I have also had problems with noise from my Avant 55 speakers, but it's repaired now.. The technicians had to change a long cable that was improperly mounted immediately behind the screen. The noise was noticable only when the screen was on, very annoying. It took a long time to figure out what the error was and basically the technicians had to change all the parts in the Avant.

Hi - I too have noticed a buzzing noise from my Avant, not from the speakers but from the panel behind the screen above the subwoofer.  It's not very loud but noticeable, especially if low level volume in operation. 

It also is only noisy when picture on screen.

Wasn't sure if this was normal/getting noisier but sounds similar to your issues.  Is this where you were hearing the noise from too?

Will be contacting the dealer regardless as its bugging me!