Onkyo to Beolab 2 sub problem

Hello. Im switching from a Beovision 12 and beosystem 3 to a Sony OLED and Onkyo receiver. I have 2 beolab 9, 2 beolab 3 and 1 beolab 2. Im using RCA + 12V tigger to Powerlink and my Onkyo is triggering with the onboard 12V trigger output. My Beolab 3 and 9 are working just fine, but Im having trouble wit my beolab 2 and a humming sound. Im routing the cables this way: RCA+Trigger - Powerlink - RJ45 - LAN Central RJ45/RJ45 - LAN outlet - RJ45 - Powerlink. With the beocenter 3, all was working just fine, but after switching to Onkyo and the adapter, I get a strong humming sound when plugging in the trigger, it gets less when I plug in the RCA to sub out on the Onkyo, but still so its annoying. If I connect a Powerlink directly from the adapter to beolab 2, the humming goes away, so I understand that something wrong in the routing am using, BUT with the beosystem 3, all worked just fine using this. So what it different now using the adapter?

Hi Tibby,

Welcome to Beoworld!  The humming will be caused by the RJ45 cables, based on your description.  You can use shielded Cat 6 STP or Cat 7 cables (not standard Cat 5 or Cat 6) for audio, but the cables must be kept completely separate from your Ethernet wiring and they mustn't run back to any common patch panels or network switches.

Ideally, please keep all of the RJ45 wiring within the room where the speakers are located and please double check that the cables and sockets are shielded, with the shield giving continuity from receiver to all speakers across the RJ45 cabling.

My own recommendation is to avoid using the 12 volt output of a receiver to trigger Beolab speakers.  Whilst some users have had success with this, all of the receiver manufacturers that I have spoken to (including Onkyo) have advised against this, due to the fact that the Beolab speakers sink the trigger voltage to audio ground, a condition which the receiver is not designed to accept.  Hence, this wiring may void your receiver warranty.

Please feel free to get in touch directly via my sponsor link below if you need help with cabling to give safe and noise-free operation of the speakers, to a quality as good or better than you had with the Beosystem.....

Kind regards, Steve.

Thanks for you reply! But why did I not get the humming sound with the beosysten 3?

Hi,

Did you use the correct Powerlink cables directly from the Beosystem to the speakers?  Adding the 12 volt trigger from the receiver may have caused the noise, or the RJ45 cables (if these weren't in place before).

If you would like to email me a sketch of your wiring layout please, then I will be pleased to assist further.  I can then help you to get everything wired in a better arrangement, to remove the noise.

Kind regards, Steve.