I've been having a play around with my BeoVision 7-40 MK V because despite my beolab 7.2 being an amazing speaker I miss having surround sound. I have an old Bose Acoustimass 3 active Sub which has a pair of passive cubes attached to it. So I connected up the sub by 5 Pin Din to Phono cable into the Bose Sub and told the TV it was a pair of 8000s as it has the crossover built into the sub. All worked but the sub buzzes. The cable is fine as I used it to test using it as an aux cable into a B&O Hi-Fi and there was no buzz. So I tried plugging my iPhone into the sub with a 3.5 to Phono cable. No buzz.Is this just a bad combo or has anyone else got similar or any other ideas? I would buy some BeoLabs but would only want a BeoLab 3 2 combo or BeoLab 9s which I just cant afford at the moment!Cheers