Isolation Questions


Silver Member
Username: Tpizzle

Post Number: 582
Registered: Apr-05
Hello everyone,

I am in the middle of costructing a "flexy" rack for my components and would like your thoughts on isolation. Two areas:

1. I need something for the feet, as they are steel rod and I have hardwood floors. I have seen everything out there from brass coned feet sitting on cupped platforms to hockey pucks.

2. For the components is it worth setting them on sorbothane, felt, etc materials or just flat on the wooden shelves?

Researching this has made my head spin as I cannot find a "general" consensus as to the importance/benefit of using these materials.

Just was curious as to what you all do.

Thanks a bunch!

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 15767
Registered: May-04

For the feet on your rack you might try a brass/stainles steel acorn nut; The rounded surface of the nut when facing downwards should not damage your floors like a spike would. However, the hardness of the material will allow the rounded surface to interface with the floor only at what amounts to the apex of the nut's surface; i.e., a tangent. This causes the rounded surface to act in a fashion simiar to a spike as far as isolating the two surfaces from each other as only a very small footprint of the nut is actually touching the floor's surface. This also serves to mass load the rack in a way similar to what spikes are intended to accomplish. The entire concept is similar to placing ball bearings under a component, only fractional amounts of the surface being supported are in contact with the rounded surface serving as the support. Depending upon the final weight of the filled rack assembly you might then want to check for any damage to the floor as different woods will be softer and harder than others. If need be, place a large washer with a very small center opening under the nut to slightly raise it off the floor itself.

"For the components is it worth setting them on sorbothane, felt, etc materials or just flat on the wooden shelves?"

You probably shouldn't be using solid wood shelves as they will have a deciced resonance which will make isolationg the components all that much more difficult. MDF or plywood is the better answer though not everyone likes the sound of either material. I would tell you isolation from the support shelf is needed but you also must in many cases couple the component to the shelf to wick away vibrations caused by the power supply. Therefore, you need to couple and decouple most components at the same time. It is impossible in a short forum answer to get to even the basics of how this is accomplished. And what works in one sistuation might be a complete disaster in another. Often, your ear will be fooled by a result that is not better than what existed but rather is simply different than what existed. It is important to try a few materials and processes before deciding which is the best for your own system. Then after you've listened for awhile, remove the device and determine whether what you've done is really all that much better or just different. I would in most circumstances stay away from Sorbothane and anything which provides a dulling effect to resonance in the fashion in which Sorbothane operates. But that's a very general piece of advice, if you think your system sounds better with Sorbothane in place, then that's your decision. Isolation tends to be a trade between taking way the life from the sound and allowing too much extraneous resonance to color the sound. There is no one answer to give that will work for every system and for every listener. Experimentation is the key, many times a commercial product is created out of experimentation and then the materials are refined down to a sellable product. The final product works no better than the knock up but looks more sellable. So experiment. Commercially the Vibrapods work well. So do tennis and racquetballs cut in half and placed under the component. Do not place your footer under the existing feet, use them in contact with the component's chassis. Isolating a turntable is almost diametrically opposite the process of isolating an amplifier. So, in short, there is no simple answer.

Here's a group of tweaks you can browse. Keep in mind most people prefer to think their experiments are a success and they will proclaim those things that are absolutuely unworthy of praise to be a "jaw dropping" success. Read these with some logic and you'll get a few ideas;


Gold Member
Username: Stu_pitt

Stamford, Connecticut USA

Post Number: 4319
Registered: May-05
Jan makes a lot of interesting points and offered some pretty practical advice.

I've found that the best way is trial and error. Not by buying expensive stuff, but by using stuff around the house or stuff that's dirt cheap that has another use anyway. Stuff like wooden cutting boards and erasers under it in the corners, hockey pucks, tennis/racquet/squash balls, wooden blocks like Jenga blocks, felt pads, etc.

What works best varies by component and the environment. Some floors transmit vibration, others don't. Some amps benefit from added mass on the chassis over the transformer, others sound worse. It all comes down to trial end error. The really expensive stuff isn't really worth your time most often. It'll look nicer though.

Then there's turntable isolation...

Gold Member
Username: Stu_pitt

Stamford, Connecticut USA

Post Number: 4320
Registered: May-05
For some ideas to kick around, go to the system pics thread and look at Micheal Wodek's stuff. It may be a few pages back. May not look great, but it'll give you an idea. I'm sure you can pretty up the stuff if you like the way it makes your gear sound.

Silver Member
Username: Tpizzle

Post Number: 583
Registered: Apr-05
Thanks for the suggestions! If I have learned anything in the hours I have researched this topic it is Jan is absolutely correct, no single definitive answer.

So far I am using MDF shelves with rubber washers in between the shelf and metal washer, both on top and bottom of each shelf. This, when paired with keeping a minimal surface area contact with each leg, should provide at least fair isolation. I am also spraying both sides of each shelf with a rubberized sound dampening material used for car trunks.

ResearchingtThis topic has proven more entertaining than informative and I just want to do it right the first time, which is why I have consulted you all thorugh this thread.

I have used this site extensively the past few years due to responses as those above, this community is great. Thanks again

Gold Member
Username: Hawkbilly

Nova Scotia Canada

Post Number: 1199
Registered: Jul-07
"....I just want to do it right the first time...."

You'd be the first, I think.

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