Building rack, which is best mass or isolation

[Polkersince85]

I thinking of building a new amp rack. Trying to decide which is best way to build it, to go for major mass/weight or to isolate it. Also, has anybody tried using magnetic levitation to isolate the shelf, with the rare earth magnets, seems like you could get enough lift to provide an air gap. Any thoughts.

[Willow]

How about mass isolation

I think you couldn't go wrong with a bit or lots of both

[madmax]

Originally Posted by Willow

How about mass isolation

I think you couldn't go wrong with a bit or lots of both

Sure, isolate a huge mass then spike your amp to it.

madmax

[neomagus00]

could there not be issues with having powerful magnets right next to the amp?

[Skynut]

Originally Posted by Polkersince85

I thinking of building a new amp rack. Trying to decide which is best way to build it, to go for major mass/weight or to isolate it. Also, has anybody tried using magnetic levitation to isolate the shelf, with the rare earth magnets, seems like you could get enough lift to provide an air gap. Any thoughts.

I think you would have a hard time getting magnets powerfull enough to hold components apart. I also do not think I would want any magnets that powerfull to be that close to my electronics.
I was thinking about using Die springs ( like valve springs ) to keep the shelves from actually connecting to the uprights.
I do not know if this is good or not but that is what I am thinking about doing when I build mine.
Mass and Isolation. Two great things that go great together.

[steveinaz]

Do you have slab construction or suspended floor? The reason I ask is that with slab construction you're only significant vibration is airborne, which is pretty minimal; where floor vibration is a tougher nut to crack and requires a different approach.

I've found (I'm not an expert mind you) that with "hard" floors, hard cone-point isolation works well; with soft floors you need softer damping like the form of Vibrapods or similar principal.

What you could do is hard isolate the amps platform, then soft isolate the amp itself from the platform.

[Polkersince85]

Thanks for the responses. I tend to think that a heavy isolated structure is best on my suspended floor. I guess you could calculate the maximum force that the vibration/sound force could produce and then exceed that with mass to overcome the kinetic energy required to "move" the stand. Maybe different materials in the uprights would have varying resonance frequencies and therefore dampen the vibration from the floor. Maybe a wood base with a layer of rubber then more wood upright, etc. Could even set it all in a sandbox. Just thinking out loud, may need to do some testing.

[madmax]

From what I understand you can't really get rid of the movement overall but you can lower its resonant frequency.

I had a realization one time when I noticed a particular bass note shaking my rack. I could play it very loud or very soft and the vibration changed very little all over the rack. The rack was VERY heavy at the time with several tube amps on it. That little bass note could rock the whole thing even at the very low volume. You really can't "remove" the energy.
madmax