Ok. Here’s my vibration treatment theory. It’s deducted from observation, logic, quit a bit of research (I have an undergraduate degree in physics) and what I have heard:
Symposium posts on its web site that it is imperative for their shelf system to properly function to have a high transmission efficiency connection between the components chassis and the shelf. This is to allow the system to simultaneously isolate from outside while draining vibratory energy from the component. Symposium relies on foam in the shelf, not rubber. And then wants no rubber elsewhere because it NEEDS to get the energy to the foam to dissipate it. Makes sense. It's a total system design. Use metal footers of some kind, bearing footer devices, or thick solid metal discs to couple the chassis to the shelf so it can do its job. It makes sense. I now realize that THIS is how Critical Mass works as well; and this is why Critical mass recommends you just put the equipment directly on the shelf or use their simple cone footer to couple the chassis to the shelf. Same exact concept. The magic is in the shelf so get ALL the vibrations to the shelf to do its job.
HRS and IsoAcoustics rely on rubber to dissipate the energy. But IsoAcoustics counts of the footers doing it alone. HRS has developed their own system integrated rubber in their footers and their shelves to dissipate the vibrational energy. I think that with rubber there is less thermal distribution. And that with too much rubber it actually seals the vibrational energy in the component as opposed to allowing it to come out and dissipate.
I think that you either should use the HRS footers alone or IsoAcoustics footers alone, unless external vibration is a bigger problem then internal vibration. I think the HRS shelf is a brick wall and doesn't allow vibrational energy IN or OUT. So in a big city, it probably makes a HUGE improvement since the vibration coming from outside is smearing everything and it gets blocked. But it also blocks any internal energy from getting OUT. The HRS footers help to attenuate the energy and relies on the (not HRS) shelf to absorb or diffuse the remaining energy. With the HRS shelf in place it just bounces that energy right back through the footer and into the component, doing more harm then good.
I any rubber based product like Sorbothane and all the other rubber products out there do the same thing. They attenuate and allow the remaining energy to PSS through and dissipate into the shelf below. So the footer alone, depending on the design, can do a really good job of improving isolation and designing vibrational energy from the component. I like using the IsoAcoustics and HRS footers, they work.
Footers like the Magico Qpods (I have a set inbound to audition) and Shunmook footers (also have a set inbound) work similarly. But the Qpod takes an extra step and have a thin layer of (probably) Sorbothane and a Cooper disc which overcomes the poor thermal dissipation of the rubber. The copper theoretically dissipates the heat and makes the aluminum, steel, copper, Sorbothane design more effective at attenuating the vibrational energy then rubber alone. It’s suppsoed to offer a bit of what the Symposium/Critical Mass style shelves do but built right into the footer. I’ll let you know how big a difference that little disc of copper makes. I’m not convinced but ill
let my ears do the judging. Regarding the Shunmook footers, they are a super dense wood and a commercial grade diamond spike. Scientifically, it’s a conundrum. But maybe the density of the ebony they use is perfect to attenuate vibration and dissipate that energy more efficiently then what the other guys use. We shall see....
Footers like standard points and cones, fancy points and cones, StillPoints, Ansuz Darkz, Symposium Rollerblocks, etc all do a great job of coupling the vibrational energy from the rack to the shelf underneath. But by focusing that energy into smaller area it permits some thermal release as the vibrational energy is forced into a volume that can’t contain the vibrational energy without forcing some out as heat. Different companies have come up with different geometric solutions to this and some work VERY well! I have gotten the best results with StillPoints, the Darkz (although I liked the StillPoints more) and Symposium Rollerblocks (but only tried also using their matching shelf). I do honestly think that you probably get more isolation and vibrational attenuation by using this last type of footer and then a shelf from Symposium, Critica Mass, Silent Running, etc.
Then there are designs like Star Sound and Artesani (and the StillPoints rack) where the entire system is built as a single whole with no real shelf. The component is coupled directly to the rack to dissapate heat and vibration, and to isolate. I have heard all three and they work, and work well. Probably amongst the best overall bang for the buck if your looking to replace your whole rack.
Im not sure if that confused you or helped. But it helped me to formulate my thoughts and opinions. As always, thanks for coming along for the ride. Lol.
Dont ask ask me what I decided on yet please. I still need to hear the Qpods and Shunmook footers. And more importantly, I need to decide if I can move my rack to the front of my room without deleterious effects. But I feel like I’m getting closer!!!!
