Do different speaker stands can really make a big sound improvement?

I always thought that important purpose of the stands is to remove vibration from the speakers themselves from the floor. But if we consider that the problem is also that vibration from the stands is transmitted back to the speakers, then it is logical that the heavier the stands, the better. However, my speakers sounded fine both with metal stands not filled with sand, and with stands made of heavy MDF. I have Buchardt S400 MK2 speakers, the original stands of which are just three thin wooden sticks. But I installed them on Q Acoustics Concept 20 stands, because they are heavier than the speakers themselves and have an anti-resonance design like their speakers of this series, thinking that it would be better. I also added sorbothane spacers between the columns and the stands. I am happy with the result. Of course, my system is far from high-end and changes of this level may not be audible on it at all. Experiment for a start simply with the weight of the stands, find something heavier than the speakers and something lighter and compare. If heavy ones are better, then it makes sense to select the material based on damping properties. If not, leave the light ones made of wood, the design will be beautiful. Well, the main purpose of the stands is to allow you to place the speakers not on a shelf, but in the correct way.

Akg 

nice very nice....

Here you go...in white oak these look to be TonTrager'ish, and a good deal.

Harbeth uses a lossy cabinet design, not a resonant one. If you think differently, I suggest you pull a woofer or drop the front panel and check out the bituminous damping pads attached to the cabinet walls. I assure you, they do not ring like a Steinway. That said, the recommended stands should be of the proper height, open design, and not couple the speaker box to the stand - use BluTak putty or small Sorbothane hemispheres at the far corners of the top plate to mount the speakers. Personally, I like the Pangaea 300 series with some autobody undercoat sprayed inside each tube to dampen them. They work well and are not egregiously priced. Mounting the speakers that way will allow the lossy, thin wall Harbeth cabinets to perform as intended. They have also worked well with my LS-50s high-mass cabinets at the 28" leg length. 

very important is the relationship of your ears to the tweeter