I know that this might be an odd question, but its something which has bothered me for ages. I have an 'Optimum2000' stand, which is basically a 1m length of 10mm glass supported at either end (its not the one with the centre support) Its already supporting a Sony KV36FS70 which is almost 100kgs and the glass visibly bends (about 5-10mm in the middle) Optimum say that they have tested the glass upto 500kgs, but won't guarantee it. But they have assured me that 100kgs is fine. However, I asked 'Pilkington Glass' about their thoughts on toughened safty glass and with the measurements I have, they said that 50kgs would be safe! So, whilst the TV has been sat there for almost a year, I enter the living room every day expecting a scene of carnage. I have always wanted to upgrade my Yamaha SW80 sub to something more meaty.. But the sub is located right behind the shelf. This may sound silly.. But I wonder if it was possible that a really loud/low frequency could vibrate the shelf/TV enough to cause the shelf to fail. You hear people talk about their subs being able to move ornaments on neighbours shelfs and I wonder if there could be enough power to vibrate the stand. If the glass wasn't already overloaded, I would be worried, but I wonder what it would take to make the shelf break. I know that there isn't an easy answer this, but I would apprecate peoples thoughts/experinences.