I have a long-standing issue with my stand mounted speakers. They are largish Spender SP1s on tubular steel stands. They sit on an old Victorian suspended wooden floor and sway a little with any movement around them. I've weighted them on top with 5kg weights. This has helped, but I'd still like them more stable. A friend suggested placing 3 small blocks under the stands (he reckons 3 legs better than 4!) Again, slight improvement but still not entirely stable. I'm thinking of drilling through the stands and screwing them to the floor. Will this work, or would it be detrimental to the sound?