I have my doubts over the effectiveness of ballast in speaker stands. My QA3030i are screwed into their stands, but the stands are resting on the carpet, without the spikes. If I push them, they do move around easily, but even if they wobbled slightly, due to walking around, I don't think the sound would be affected. Any movement would be very occasional and not moving at anywhere near the speed of sound. Movement caused by traffic will also be at such a low frequency and be unable to move the speakers around enough to cause timing issues. If you could shake your speakers around at similar frequencies as the music, then you would expect timing issues and distortion. In the real world, there's nothing to cause this. The obsession with ballast, spikes and other stuff seems odd when you consider many bookshelf speakers do indeed end up in bookshelves, or on top of tables etc. How effective are stands, with or without spikes or ballast? Many speakers are allowed to rest on top of stands and many people don't bother with the spikes, or ballast. I think a lot of this has been generated by obsessive nerds and nobody seems to question if it makes a difference or not. Speakers screwed into stands and then spikes screwed into the stands, filled with lead shot, or sand and then all this sat on top of a slab of granite etc. It all seems like overkill to me. If speakers and stands are made of inert materials and there are no vibrations or energy reaching the drive units, then spikes, sand, lead shot, granite won't make much of a difference. If you have pets and/or kids running round, then I can understand people wanting their mass loaded stands, but you need to make sure the speakers are either screwed, or glued to the stands! There are many urban myths in the HIFI sector and this stuff, along with bi-wiring mentioned in another thread, are typical examples of 'tweaks' without any research to prove these things do actually work. I was looking for sand on the Futureshop site and was actually surprised there are no listing s for 'special' anti-vibration sand at £300 per kilo. I might email them to see if they can find some.