Well, I guess a good engineer could put drivers and an amp inside a concrete block that weighs about 300 pounds. Doubt it would sell very well. And Vibration dampening systems ARE important under turntables at the very least, regardless of what you are playing said turntable through.
Powered speakers show audiophiles are confused
17 of 23 speakers in my studio and home theater systems are internally powered. My studio system is all Genelec and sounds very accurate. I know the best new concert and studio speakers are internally powered there are great technical reasons to design a speaker and an amp synergistically, this concept is much more important to sound quality than the vibration systems we often buy. How can an audiophile justify a vibration system of any sort with this in mind.