@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.
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.