Bose soundbar 500- need your opinions

Hi there! I' ve got an interesting question that made me think and try different placements for my gadget. I have Bose soundbar 500 and it stands right under my TV-set in 25 cm from the wall. It sounds great but I thought what if it can do better on a larger distance. So, I replaced it and the distance was 4o cm. The sound didn’t change and that’s why I put it back on its previous spot. You can see here more information and after express your opinion- weather I am right or wrong, as I think that the place for the soundbar has some importance. What do you think? Where is the best place for the soundbar? Does it have any meaning at ll?