Isolation feet

[Islander]

As I posted in the CD Player Modification Voodoo? thread:

"As for resonance control under the player, I was a skeptic until I tried it and heard the difference for myself. I bought a new audio stand direct from the manufacturer in Calgary and he sent me three mushroom-shaped ceramic footers to try under any component.

I put them under the disc player in what seemed like an even weight-bearing pattern and noticed more clarity, but Leonard Cohen's voice had a higher pitch that I didn't like. I called the manufacturer and he said try a symmetrical pattern and you should hear a difference. To my surprise, I did! The voice was back to its normal pitch and the clarity was still there.

Replacing the ceramic footers with the heavy maple board gave further improvements, so it's still under the player now.

Trying these things cost me nothing and the sound is improved, plus I learned something I didn't know or wouldn't have believed before. I thought that was all good."


The maple board is a kitchen cutting board, 12" x 16" x 1.5" thick, with small rubber feet. It's made of solid maple and weighs around 7 lbs.

[greg928gts]

I made a dozen "feet" by cutting 1-1/4" round wooden dowel to about 1-1/4" lengths and then inserted a tiny brass screw and washer into the top of each piece.

I replaced the magic cones [] under my transport, DAC, and power supply (all stacked) and it did make a difference. I didn't like it as well so I've switched back. But I intend to try some different feet and also some hardwood platforms.

Interesting stuff.

Greg

[Islander]

That stand manufacturer that I mentioned is called Skylan and the owner, Noel Nolan, has done a fair bit of experimentation with resonance control. I've had some interesting talks with him about his component stands and his speaker stands, which are used and recommended by Harbeth.

He also made an isolation platform of two layers of hardwood with a rubbery material between them and tried various thicknesses and types of material to find the optimum. Sometimes with items like that, the cost is not in the materials, but in the time needed to find out what works and what doesn't.

Of course, for people who like to spend money, there are manufacturers who make something similar out of carbon fiber and charge hundreds for it.

Here's a review of a pricey complete solution, the $9000 Harmonic Resolution Systems M1R Component Stand:

http://6moons.com/audioreviews/hrs/m1r.html

It's very expensive, but on the bright side, it is beautiful and his wife also thought it looked great.

[greg928gts]

Here's a review of a pricey complete solution, the $9000 Harmonic Resolution Systems M1R Component Stand:

I think I'll run right out and buy me a couple of them! []

Greg

[Don Richard]

Results would be influenced greatly by the CD player itself. A player with more solid construction, or a better clamping mechanism, or a software "shock buffer" such as car audio players have will be more immune to vibration and microphonics. Age and wear on a player will also affect results.

Turntables and equipment with vacuum tubes need to be isolated better so that acoustic feedback will not distort the signal.

Or we could all just go to Ipods with solid state memory and none of this can happen[]

[greg928gts]

More listening, and I still stand by my original comments. I'm still shocked at the difference this made with my system and I can't believe I never knew about or tried this before.

The imaging is so incredibly focused that sometimes it's too much. By that I mean that the guitar, bass, and vocals will sometimes be lined up behind one another all right in the middle of my room. I think it depends a lot on the recording. Just listened to Kamakiriad all the way through and on two songs the image was too tight, but on the rest it was just spectacular. One song in particular just had the most incredible separation of instruments, and where before I would hear sounds, I was now hearing organ, guitar picking, kazoo (might be synth), wood block percussion, Rhodes piano, horn section, and of course drums and bass.

Just thought I'd update and let everyone know it wasn't just a fluke or voodoo.

Greg

Jamboree bass bins, K402/K69, passive networks (5db attenuation on K69), Scott 299A, my usual CD front end, 16 x 22 x 9 room.

[Audio Flynn]

Nice report Gregg. I would add copmponent isolation to the long list of fine tuning tweeks including micro-speaker placement, reducing diffractions, cable routing and so on.

Cable routing, I hate cable routing. If anybody takes their HT apart cable by cable and does DEOXIT or whatever every 3-6 months they are my idol.

I realy need to do the 2 channel rig more frequently.

I know I get reduntant after a while but wine corks seem like a good try on the cheap. Just do not drink wine with screw caps.

My TT does all its balance and isolation from 3 threaded aluminum cones. I am not real sweet on Aluminum but it owuld be a time consuming endeavor to convert to brass. The JA Michel can certainly be bested by a VPI Scout or an MMF-9 but she is a quality peice of early JA Michel histroy. A company that was dedicated to vinyl before it was cool in the dark ages of the 80s.

[Batmans Robin]

More listening, and I still stand by
my original comments. I'm still shocked at the difference this made
with my system and I can't believe I never knew about or tried this
before.

The imaging is so incredibly focused that sometimes
it's too much. By that I mean that the guitar, bass, and vocals will
sometimes be lined up behind one another all right in the middle of my
room. I think it depends a lot on the recording. Just listened to
Kamakiriad all the way through and on two songs the image was too
tight, but on the rest it was just spectacular. One song in particular
just had the most incredible separation of instruments, and where
before I would hear sounds, I was now hearing organ, guitar picking,
kazoo (might be synth), wood block percussion, Rhodes piano, horn
section, and of course drums and bass.

Just thought I'd update and let everyone know it wasn't just a fluke or voodoo.

Greg

Jamboree bass bins, K402/K69, passive networks (5db attenuation on K69), Scott 299A, my usual CD front end, 16 x 22 x 9 room.

Oh well if you say the same thing the second time I am now convinced!!! [] [<)] [bs]

[greg928gts]

When Batman broods, clouds gather over the city.

Batman developed this ability to control the weather so that the bat-signal would never beam fruitlessly into outer space on a clear night.

[pauln]

My favorite kind of thread! Let's examine the possibilities. Otherwise you might be using them upsidedown...![]

If they just isolate, then not only do they prevent vibration from entering the component, they prevent vibration from exiting the component. If they just conduct vibration out of the component, they also conduct vibration into the component. If they both conduct and isolate, perhaps differentially as in the mechanical diode theory, then the theory would imply that the dominant direction of conduction would be one way and the dominant direction of isolation would be the other... so let's examine which direction these might be.

There are 17 possible ways for the cones to operate on vibrations as far as direction is concerned:

These things either just "isolate" vibration non-differentially in both directions towards and away from the point,

or they just "conduct" vibration non-differentially in both directions,

or they isolate differentially based on the direction of the vibes (two possibilites based on the favored direction polarity),

or they conduct differentially (two possibilites),

or both just isolate and conduct non-differentially,

or isolate non-differentially but conduct differentially (two possibilities of the later, so three total),

or the above case visa vera (three possibilites, see previous above),

or both isolate and conduct differentially (four possibilites, you do the math).

All that without yet considering any possible frequency changes.

There are 16 possible ways for the cones to operate on frequencies as far as direction is concerned:

These things all pass, high pass, low pass, or band pass going toward the point and/or all pass, high pass, low pass, or band pass going toward the base.

This looks like 272 possible ways these cones might operate, and I used simplified categories of possible mechanical operation.

Now lets see what the polarity might be for those cases where the magnitude of the conduction or isolation (or both) of vibrations through the cones acts differentially depending on the direction.

Does the cone shape act like a horn and make the vibration increase going from the point to the flare (and reduce in the opposite direction)? Or, does the greater flare base area take a given magnitude of vibration and increase it (concentrate it) when vibration goes in the direction toward the point (and visa versa for the opposite direction)? That is, which might be the conducting direction and which the isolating direction?

Since the typical geometric orientation for the use of footer cones is for the points to point down, it seems that the mechanical operation assumptions would be that the cones act more as conductors for vibration traveling in the down direction (to "bleed off" vibes from the component), and act more as isolators for those vibrations going in the up direction (to block vibes from entering the component). Depending on the theory of mechanical operation, one might also assume that the theory would have the cones acting as vibration magnitude concentrators in the down direction (acting as an energy "sink" or absorber/damper at the base end of the cone), and as magnitude reducers in the up direction (mechanical impedance mismatch/vibration diffuser).

I can almost imagine that they actually work, the question remains, if they are doing something, what is it, and how? Anyone have some cones, a test source, and a scope?

[greg928gts]

Anyone have some cones, a test source, and a scope?

Nope. No scope for me, I use my ears, and I rejoice in the notion that there are hundreds of other possibilities to occupy my time long beyond the usefulness of my ears. One thing I've learned about being an audiophile is that the sound will never, ever be completely right.

Greg

[HarryO]

I ran into the same thing a couple of years using a Denon DCM444.

A friend of mine gave me some cheapie brass cones that attached with double backed tape discs and I tried them. The clarity was greatly improved.

I attributed this to the placement of my CDP close to my speakers in a small room. I've done this to all my CDP's since trying with and without. Some I noticed no differences in but others the difference was very noticable. My ShengYa tube CDP greatly benefits from Isolation. It's a very heavy unit and I figured it wouldn't make any difference.

I also use foam blocks to isolate vibrations from my tube preammp and tube amps. There's a noticable difference on some tubes.

I'm not sure it's a cure-all for all systems but for some it's a must.

Harry

[HarryO]

Here's the foam blocks I use on my CDPs and tube preamps.

Cheap and effective. I think about $6.00 for a set of 4 if I recall correctly. I bought them after finding out isolation can make a difference.

[Bill H.]

disregard...................

[fini]

Here's the foam blocks I use on my CDPs and tube preamps.

Cheap and effective. I think about $6.00 for a set of 4 if I recall correctly. I bought them after finding out isolation can make a difference.

Harry, I use those same blocks under my turntable plinth. They're designed to damp vibrations from AC units and such on roofs, etc. Available at HVAC supply houses.

[BLSamuel]

Harry, I use those same blocks under my turntable plinth. They're designed to damp vibrations from AC units and such on roofs, etc. Available at HVAC supply houses.

@* Fini. Reading my mind again. [:S]

I was going to ask Harry where to get them. Found the DiversiTech Wagner website but couldn't find those though didn't look real long.

[fini]

Grainger has 'em made with cork inside.

[BLSamuel]

Grainger has 'em made with cork inside.

Something like this?

This is 2x2x1" http://www.grainger.com/Grainger/items/5C027

They come in many sizes. I think these are 2 for $3.51 plus shipping etc...

So how so these compare to the foam pads?

I was thinking of trying the tennis ball or raquetball in a frame with a heavy paving stone under my turntable. This would be simpler.

[fini]

So how so these compare to the foam pads?

I was thinking of trying the tennis ball or raquetball in a frame with a heavy paving stone under my turntable. This would be simpler.

Beats me. They kinda look like burned waffles with nougat in the middle. Mmm!

I also use handballs siliconed to rubber furniture cups under a sandstone slab (on which sits the turntable and foam pads). Kinda like wearing a belt with suspenders.

Right now I'm trying to figure out how to reduce the turntable motor noise I hear (through the system), specifically in regard to plinth design. In other words, I want to build a plinth (for my TD-124) that incorporates some type of sound damping. Trouble is, I don't know how all this works. Can vibrations be "bled off" the turntable body, so that they don't end up being picked up by the stylus? I will be doing everything I can to isolate the motor from the chassis.

[fini]

So how so these compare to the foam pads?

OK, I did a little googling and found this PDF.

LIT-FLY-CLAD.pdf