What's the best isolation system?

there is no doubt that the best isolation system is a combination of mass and air suspension, tuned properly and in layers. the concept is the extreme example of a constrained layering. the mass keeps the air from influenceing the next layer.

my Rockport Sirius III turntable seems to be an excellent example of this concept. if you consider what a siesmograph does then it is easy to understand that to some degree a phono stylus acts as a siesmograph. in addition to earth movement you have low-frequency vibration thru the floor from the speakers. the Rockport starts with a 250 pound stand, has an self-leveling air suspension, then a 200 pound plinth, then an air bearing, then a 65 pound platter, then the stylus and arm, then an air bearing on the arm. only the platter, record, stylus and arm wand (not the arm assembly) have any contact during play.

the influence of air born vibration is minimized by the mass of the platter and the arm design. when you hear the result of this over the top approach it is clear that it surpasses any other approach. i think it safe to say that a turntable is the item most influenced by vibration.

is this approach practical?...maybe not....but it is the best isolation system.

Subaruguru, if YOU think it qualifies....then it does.

strickly speaking, whatever assembly that is holding your amps onto the ceiling (some sort of bracket or strap) would be the suspension. if they are rigidly attached....there is no isolation.....especially if the speakers are on the suspended floor above....any vibrations would travel into the amps.....which may or may not be a big deal.

btw, good idea for space efficiency and WAF effectiveness.

this thread is so ’2002’; if you scroll up you will see posts of mine from 18 years ago. but things have changed and technology has moved on. there is a new sheriff in town, it’s called ’active isolation’.

https://forum.audiogon.com/discussions/active-isolation-what-can-it-do-for-music-reproduction

as far as magnetic levitation; it’s passive and has it’s pluses and minuses. i used to own an SAP Relaxa 1 mag-lev table, which was just ok. there are other passive approaches that are better. mag lev and hifi are best together with turntable drive systems, not isolation from feedback resonance.....IMHO.

but no passive can touch active when your situation allows active to be used. active has limitations which the thread i linked address. it’s not a one size fits all solution. but it is the best isolation solution yet devised. it’s what state of the art science and industry uses

there is passive, that in essence is a spring. it floats, settles, overshoots, and is soft. even the best possible passive isolation works like this.

then there is active which reacts to perceived resonance; it’s stiff since is can start and stop. passive cannot start and stop. at it’s best it can only self level.

active is very effective at low frequencies, but over 200hz it’s benefit diminishes.

passive struggles to attenuate at really low ’ground noise’ frequencies (under 5hz). it get’s down there but it’s level of attenuation is marginal. that is where active is ideal. OTOH passive is much better than active at higher frequencies (over 200 hz).

in a micro-nano particle context i agree active has the same weaknesses, simply much much less than passive.

but science and industry accept the precision of active isolation to help them accomplish appropriate tasks effectively.

agree it’s expense is prohibitive. i got a little carried away. i do appreciate having it though. someone has to be at that end of the music reproduction resonance isolation bell curve.

@lloydc
the active devices i use (Table Stable TS units) use piezo electric sensors to sense the resonance in 6 axis, and piezo electric actuators to compensate for that resonance. they only make any noise when they level the load when fist turned on; after that they are dead quiet as far as ambient noise. i have 5 of these units in my system, they are turned on 24/7 and are dead quiet and all within 7-8 feet of my listening position.

when you say ’pumps’ i would expect you are referring to an air bladder type of resonance control. that type is passive, the air bladder acts like a spring and will float and settle. the pump would only be used to level the bladder, and would not actively react to resonace, only the level.