Isolation Feet Recommendation for Equipment Rack


I just bought a 4-tier equipment rack to set up a 2nd system. It’s not audiophile standard and comes with standard spikes. The sound quality of the system is decent with this rack but I intend to replace the spikes on the rack with something else in the near future and was wondering about the available options.

The target support weight inclusive of the rack is up to 150 lbs (on a more accurate level it's around 130lbs). Apart from the Isoacoustics Gaia, are there any other worthy options around the same price range? What about the Finite Elemente stuff such as Cerabase and Cerapuc? I have the FE Cerapuc installed on the equipment rack in the main system but did not compare the Cerapuc with anything else for the past 15 years of ownership.

I would appreciate experiences from folks who have switched from spikes to any of the "audiophile standard" isolator options on the equipment rack, going from coupling to decoupling. These isolation feet will need to bring some noticeable if not significant change or improvement to the sound quality of the system after they replaced the spikes on the equipment rack. If the difference is subtle to the point of negligible, or the sound becomes worse instead of better, I’d say forget it.
ryder
Right. Not only turntables, all our components have to contend with a plethora of vibration sources.

There are, at a minimum:

1. Vibrations generated within the component itself. Even zero moving parts components like amps and DACs generate a lot of vibration. With turntables there is at minimum motor, bearing, arm and cartridge. The cartridge alone generates so much vibration you can hear music coming right off the cartridge.

2. Mechanical environmental structural vibrations. This is everything from traffic outside, wind acting on trees and structures, that all adds together into seismic vibrations, mixed into which we have speakers mechanically transmitting vibration into the floor, and from there to walls, ceiling, rack, combining with seismic and into components.

3. Acoustic, the air, what we call sound. All the noise in the room. Hopefully mostly music but for this purpose it really does not matter it is all noise.

This is actually the least of the three, something you will appreciate if you ever put your speakers on Podiums and feel the difference. But acoustic energy being air affects different structures differently. Sound waves vary in length by frequency. A tweeter can be small, because the wavelength is very short. Tweeters will move at lower frequencies of course, you just won’t hear it. What happens is the pressure wave instead of being driven forward dissipates around the sides. A speaker cabinet is basically a means of preventing this. Without it, speaker in open air, loses all lower frequencies.

Now we have what we need to know to answer your question. The tone arm is so small the only frequencies that even "see" it are ultrasonic. Everything else goes right around it. Plus it is curved, makes it even harder for acoustic energy to go into the arm.

Turntable, bigger, is easier. Now it should be clear why a dust cover is so bad, great big thing practically designed to collect acoustic energy and channel it into the turntable.

Springs under turntables and other components don’t have much to do with acoustic energy. Mostly they isolate from environmental seismic vibrations. The biggest source usually being the component itself. Springs allow vibrations generated within the component to be dissipated within the component. This might not seem so great but it is a lot better than the alternative, which is vibrations travel beyond the component creating ringing in the rack and exciting all the other components until every component is causing every other component to ring in a great big smeary mess. This is the real reason springs work so well. They break that whole messy cycle.
@millercarbon

Thanks for that thoughtful answer.  Makes perfect sense that my Rega P8 does not come with any attached dust cover.  I have just ordered 3 Giai feet to try under the turntable.  Stunning that some of the isolation units for speakers cost more than some speakers I've owned.  I'm sure the law of diminishing returns applies to these.  
Townshend Seismic Isolation Corners. Mike drop.

Rack and components in/on the rack are isolated down to 3Hz from all external vibrations.

To take it 1 step further, listen to millercarbon, for springs under every component for individual component vibration control.

Or reach for the stars with Townshend pods under every component. Sub and amps included.

I’ve done all of the above(and Townshend podiums and platforms and Symposium Platforms where inadequate height for pods).

Do not allow component feet to be the isolation.

Best of luck.
I have brass cones and granite on the bottom shelf and 2 inch thick maple shelf’s ,I use Stillpoints  which are excellent under 
my gear.