Equipment isolation and vibration damping.

[YashN]

I found these on Amazon...just copy/paste this into the search function. They are $25 after shipping but that is for ten, enough for two sets of 4 or three sets of 3.

 

Imperial 6962 Concave Style Freeze Plug 1-5/8", Zinc Plated (Pack of 10)

 

[ATTACH=CONFIG]19326[/ATTACH]

 

I don't know if they would be smooth enough. Perhaps they could be polished? The main issue was that they are not glass. Thoughts?

 

Saw those as well when John S. mentioned Amazon, but the large photograph doesn't show a very smooth surface. Maybe if a Dremel can polish them.

[YashN]

Separate *momentum* problems from *energy* problems until you have fully described each.

 

From post 152 in:

 

http://www.computeraudiophile.com/f8-general-forum/equipment-rack-and-isolation-suggestion-16048/

 

 

 

Very cool post and related thread, Sam.

[InfernoSTi]

Saw those as well when John S. mentioned Amazon, but the large photograph doesn't show a very smooth surface. Maybe if a Dremel can polish them.

 

Well, I decided I could throw $25 away on finding out, so I've ordered a package and will report back on their smoothness. I think a little polishing with some emory cloth or something would be fine. I think having to use a Dremel may be a little too much work (I'm worried about being uneven and that being worse). If it doesn't work out, I should be set for the next ice age (as far as freeze plugs are concerned).

[YashN]

It's a holiday today, so we had the idea of trying out two sets of ball bearings under the speakers, in a very temporary arrangement. We spent a good couple of hours listening to various pieces.

 

Bear in mind that this is not an ideal implementation: we could use chrome steel instead of marbles, a smoother and stronger concave surface (even though it's metal), damp the cups better, use a smoother material than the upper platform (bamboo), better couple the speakers to it (we just laid the speaker on top), the speaker is now inches above its initial position, bringing closer to half the roof height whereas 1/3 may have been better), roof reflection effects come into play.

 

So taking this with these caveats, this is what we found:

 

1. Sounds are less located within the speaker, the soundstages are sometimes much bigger!

 

2. There is a much greater clarity to the mid-range and above: new sounds and new textures to sounds are revealed. The high mids to high frequencies are very clean and defined. There are sounds and rhythms within songs I know since I was a teenager that are new to me (one Depeche Mode track on Some Great Reward did that)

 

3. We found that the delineation among instruments were much clearer now: instead of instruments melding together to some degree, this time both spatial cues and timbre were more separated and clean.

 

4. The previous two points also apply to voices: with a lead and backing vocals: both are very clearly articulate and intelligible, we can perceive the nuances very well. Choral groups appear much larger! Moreover, within a backing vocal segment, the individual harmonies can be heard quite distinctly!

 

5. She found that the music has more of a 'floating' aspect to it now: The soundstage is larger for her and some sounds, like bell-like tones appear to come from the sides (probably helped by the Totem Mites own characteristics shining through better). She also made a very interesting observation: she found that she felt vibrations at her feet. After discussing that and checking manually at the stand bottom, she later found that the vibrations were actually not being transmitted by the floor, but rather straight through the air.

 

6. I found that felt like I was finally hearing reverb tails and thus the space of individual instruments much much better now.

 

Some of the odd aspects that I found, but I am prepared to put this on the higher placed speakers and the less than optimal temporary arrangement as in the list of caveats described in the introduction rather than flaws with the notion of the ball-bearing isolation are:

 

a. There were huge variations in power, slam and bass and overall volume for some songs when transitioning from one to another, not unlike what you'd expect with bass in the wrong phase. Some songs now sounded very low and other very loud.

 

b. Oddly, I found a couple of songs which gave me the impression that they were playing slower than usual, as if the groove had been lost.

 

c. I found that the soundstage appeared less deep than before sometimes. I had less of the feeling of 'they're here' than before.

 

d. The bass seems less than before, and the speed of attack transients as well.

 

Overall, we're very glad we tried this. All the odd things and seemingly negatives are, I believe just a matter of cleaning up the implementation and further tweaking my setup.

 

For instance, I believe that the impression of less bass is actually a good reduction of bass bloat, and provides enough space now for micro-details to emerge in the mid to higher frequency range. We can still hear deep bass notes nevertheless.

 

I will need to investigate the seeming loss of attack transient rapidity, but I do think the timbral accuracy has improved.

 

The soundstage may appear less deep than before sometimes, but I think with further tweaks it will ultimately be more accurate.

 

So, to me, this is one tweak that you will not want to remove once you try it.

 

I have been thinking of a way to also add the vertical isolation for speakers (you don't want them to fall off with the air-cushion), I do have an idea which seems pretty cool.

 

Looking forward to floating the amp, the iMac, the HDD, and the DAC (and the listener too!)

[InfernoSTi]

I've got my 1/2" 6061 aluminum plates in and they are very nice. I picked up three at 12"x18" which will be perfect for under my DAC, pre amp, and my CAPS computer. I received the 1/2" stainless steel balls, as well. I'm still waiting on the "dishes" which I think will be the difficult part of the whole deal. I did try the balls between two of the plates and WOW is that slippery. They just glide/slide with no effort (gravity is enough). I see why the dishes are needed.

 

Here are the plates (the other side is "clean" with no printing).

 

 

John

[AnotherSpin]

Bear in mind that this is not an ideal implementation: we could use chrome steel instead of marbles, a smoother and stronger concave surface (even though it's metal), damp the cups better, use a smoother material than the upper platform (bamboo), better couple the speakers to it (we just laid the speaker on top), the speaker is now inches above its initial position, bringing closer to half the roof height whereas 1/3 may have been better), roof reflection effects come into play.

 

 

My initial impressions were close to yours. Space, air, better defined instruments, speakers "disappeared", etc.

I would suggest to avoid bamboo on a top of the balls. If you will go for marble plates, be very careful in choosing not only "non-ringing" plates, but go for hardest you could get. I made a mistake of ordering beautiful natural mediterranean marble plates (not cheap too) to find out they are not hard enough to avoid denting with balls under heavy speakers. Try to float DAC first. I could'n want to be without tires as well.

[YashN]

Bear in mind that this is not an ideal implementation: we could use chrome steel instead of marbles, a smoother and stronger concave surface (even though it's metal), damp the cups better, use a smoother material than the upper platform (bamboo), better couple the speakers to it (we just laid the speaker on top), the speaker is now inches above its initial position, bringing closer to half the roof height whereas 1/3 may have been better), roof reflection effects come into play.

 

Some of the odd aspects that I found, but I am prepared to put this on the higher placed speakers and the less than optimal temporary arrangement as in the list of caveats described in the introduction rather than flaws with the notion of the ball-bearing isolation are:

 

Adding a couple of items that I missed mentioning yesterday in the odd aspects department:

 

e. On one track with acoustic guitar, the timbre seemed very off.

 

f. On a few tracks, I thought I could hear a doubling of the attack, especially noticeable on the kick drums. Wasn't apparent on all tracks.

[YashN]

Tested the X, Y displacements by measuring with the iPad resting above one speaker while music is playing vs the iPad resting on a table top in an adjacent room.

 

The X displacement shows no change, but the Y displacement graph, which is along the driver axis shows a displacement amplitude of 10 times more than when stationary.

 

This could explain some of the odd things heard.

 

The bamboo/marble interface isn't ideal as both surfaces aren't as smooth as marble/steel or steel/steel.

[YashN]

I would suggest to avoid bamboo on a top of the balls.

 

Try to float DAC first. I could'n want to be without tires as well.

 

As a first test, bamboo is not ideal but this is just a test: it is definitely not at smooth as marble or a metal plate. In fact, Barry proposed a first low-cost test with egg holders and marbles, which is a far cry from the result you should get using a metal cup and steel-chrome or tungsten.

 

My test is: marble ball, metal cup, bamboo platform.

 

The idea isn't to avoid the vertical isolation: it's just the air-cushion under the speakers isn't very stable for speakers in the long term. The speakers are rather elevated and if the air-cushion deflates suddenly and/or non-uniformly, this could cause the upper air-bearing platform to become unstable and the speakers would undergo quite a damaging fall.

 

So, for the speaker, if I can make an alternate implementation for vertical isolation that would be interesting. For the other components, the vertical isolation by inner tube is fine.

[YashN]

The Townshend Audio website is back up, and from it, I came across this little gem yesterday, complete with explanations and cool illustrations:

 

Earthquakes on Hi-Fi

[AnotherSpin]

The idea isn't to avoid the vertical isolation: it's just the air-cushion under the speakers isn't very stable for speakers in the long term. The speakers are rather elevated and if the air-cushion deflates suddenly and/or non-uniformly, this could cause the upper air-bearing platform to become unstable and the speakers would undergo quite a damaging fall.

 

So, for the speaker, if I can make an alternate implementation for vertical isolation that would be interesting. For the other components, the vertical isolation by inner tube is fine.

 

Yes, I was speaking about the tubes under components. In fact, I found out, that putting the tube under my heavy tube amp gives something to the sound I do not like. So, I do not use tubes under speakers and amp, only balls/bowls. Also, it is quite critical to have tubes only slightly inflated.

[YashN]

putting the tube under my heavy tube amp gives something to the sound I do not like. So, I do not use tubes under speakers and amp, only balls/bowls. Also, it is quite critical to have tubes only slightly inflated.

 

The thing with the inner-tube air-cushion is that since it is only slightly inflated, it will move in all directions, secondly, the rubber+air resonant frequency isn't mentioned.

 

In my own manual shaking macro tests with the air-cushion + the cup-and-ball, the vertical motion of the air-cushion can exacerbate the vertical motion of the cup-and-ball as well (bear in mind this is at macro level and the micro level of normal use could well be different).

 

It may be easier to find suitable spring-based arrangements for the vertical isolation, not unlike what Townshend does.

 

That linked paper above is very interesting, but even with seismic isolation, the listener is still moving...

[YashN]

I just rested the HDD flat on a triple cup-and-ball:

 

There definitely is a cumulative benefit: big soundstage and clarity in the mid-to-highs.

 

Choruses are huge.

 

Bass is deep, not boomy.

 

Listening to Alpha Blondy - Jah Victory - La Route de la Paix.

 

[jabbr]

Here is a simple and inexpensive implementation.

 

I founds some aluminum discs on ebay, ordered some 50mm concave mirrors and some 1/2" ball bearings. Silicone putty attaches the mirrors to the discs.

 

On the undersurface of the equipment flat mirrors can be attached with putty but it would be easier to use a flat sheet of tempered glass (or aluminum if available).

 

[Daudio]

Here is a simple and inexpensive implementation.

 

I founds some aluminum discs on ebay, ordered some 50mm concave mirrors...glass (or aluminum if available).

 

 

jabbr,

 

Cool !! Links please

[AnotherSpin]

I just rested the HDD flat on a triple cup-and-ball:

 

There definitely is a cumulative benefit: big soundstage and clarity in the mid-to-highs.

 

Choruses are huge.

 

Bass is deep, not boomy.

 

Listening to Alpha Blondy - Jah Victory - La Route de la Paix.

 

 

Yes, it works, I have HDD on alu bowls / chrome balls as well. In fact, I use it under all components.

[AnotherSpin]

It may be easier to find suitable spring-based arrangements for the vertical isolation, not unlike what Townshend does.

 

When you will find easy cheap good looking practical solution alternative to tubes, do not forget to share;)

[AnotherSpin]

Here is a simple and inexpensive implementation.

 

I founds some aluminum discs on ebay, ordered some 50mm concave mirrors and some 1/2" ball bearings. Silicone putty attaches the mirrors to the discs.

 

On the undersurface of the equipment flat mirrors can be attached with putty but it would be easier to use a flat sheet of tempered glass (or aluminum if available).

 

 

I found out by experiments that even small amount of glue would damp the sound. For example, I put a little amount of glue between hard plates and speakers bottoms because contact was not ideal and later found out it damped the sound. Removed glue and good sound was back. Also, I am avoiding glass. Even thin 2 mm alu plates above balls/bowls are good for me, although I am going to get thicker better quality alu plates and maybe go away from bamboo completely as well.

[Sam Lord]

+1. Very practical, simple and working ideas. No bullshit from school study-books.

Very cool post and related thread, Sam.

 

Thanks AnotherSpin and YashN for the kind words.

 

I've got my 1/2" 6061 aluminum plates in and they are very nice. I picked up three at 12"x18" which will be perfect for under my DAC, pre amp, and my CAPS computer.

 

I'm pretty astounded that folks here are taking on projects that need ultra-precise machining to compete with the better off-the-shelf components. But if it works!!! .

 

You might want to try 7075 aluminum. It's much harder and also machines more easily than 6061, which has a greater toughness. However, I couldn't remotely say which quality is more desirable in this application.

[Daudio]

I found out by experiments that even small amount of glue would damp the sound...

Also, I am avoiding glass. Even thin 2 mm alu plates above balls/bowls are good for me, although I am going to get thicker better quality alu plates and maybe go away from bamboo completely as well.

 

I agree about avoiding glue and other squishy stuff !

 

Why avoid glass ? Possibility of fracture ?

 

I was at a local non-chain, well stocked, hardware store yesterday, and noticed some small Stainless Steel sheets (4" x 8" x .018" thick) (about 10cm x 20cm x .45mm). It was next to the brass and SS tubing, so may be from K&S.

 

I am considering buying some for the equipment underside surface. I just need to find a way to cut the sheets into smaller pieces without warping them. Still looking into SS camping mirrors, to find an inexpensive source.

[bdiament]

...You might want to try 7075 aluminum. It's much harder and also machines more easily than 6061, which has a greater toughness. However, I couldn't remotely say which quality is more desirable in this application.

 

Hi Sam,

 

When I first had my Hip Joints design machined, I had prototypes made in both 6061 and 7075.

In the listening, I felt the 7075 was the better one (though I wouldn't call the difference "night and day"), so I had all the ones for my system made from the 7075.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[bdiament]

...Why avoid glass ?...

 

Hi Dave,

 

Glass rings like a bell and will color the sound, making it tend toward brightness or forwardness.

In my experience, optimal isolation will *not* alter the tonality.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[AnotherSpin]

 

Why avoid glass ? Possibility of fracture ?

 

I was at a local non-chain, well stocked, hardware store yesterday, and noticed some small Stainless Steel sheets (4" x 8" x .018" thick) (about 10cm x 20cm x .45mm). It was next to the brass and SS tubing, so may be from K&S.

 

Barry answered about glass already. Steel - the same issues, I'd prefer to use aluminum here.

[YashN]

When you will find easy cheap good looking practical solution alternative to tubes, do not forget to share;)

 

Already did: a large spring would do. If you opt for several springs, you would need to ensure the lowest combined natural frequency.

[YashN]

Steel - the same issues, I'd prefer to use aluminum here.

 

What if the steel was combined with a rubbery material and perhaps a layer of wood?