Equipment isolation and vibration damping.

[YashN]

I tried more expensive square shaped thick bamboo boards of layers construction, both horizontal and vertical. Such as:

 

[ATTACH=CONFIG]19770[/ATTACH] [ATTACH=CONFIG]19771[/ATTACH]

 

These look quite cool for vibration dissipation.

[YashN]

I have read that marble tiles to go under the equipment (above the roller balls) should be 1/2" thick. I am having no luck finding them; all I find is 18"x18", 3/8" thick tiles. How critical is this?

 

Also on the same lines; 3/4" birch plywood is common, 1" is special order; again is it critical or not a deal breaker.

 

 

I would check how much they ring when tapped. You may find the sound of wood more natural, but the thing with wood is that the surface may dent after a while, and then the motion of the ball won't be smooth and can even induce sonic colorations.

 

So, if you do get marble or some other material which does not ring much, that would do. Or and alternative would be a few layers of material, e.g: metal (in contact with the ball) stuck to wood, or a sandwich of metal layers with something like rubber in between.

 

The upper surface also needs to be coupled to your equipment. On the other hand, if you're also managing air-borne or internal vibration with feet, it will be some form of intermediate coupling.

 

Best to try several alternative and see what gives.

[YashN]

While on my way back home tonight, noticed the shops were opened till later today, so headed into an old Chinese shop and asked for metal balls or some other type of balls, and looked around for a while until the old woman shop-owner showed me some crystal cuboid blocks with a slight concavity in them.

 

I think these might do: they're $5 each.

[Foggie]

When using marble under components and on top of bearings -- what size tile?. Barry mentioned 20x20 plywood -- does this mean 18x18 x 3/8" marble tile or smaller tiles eg 12x24 that are 1/2" thick -- Home Depot doesn't have 18x18x1/2 -- what are people using?

 

The 20x20 reference was for for spkrs I believe? 18x18 is a size that will accommodate most components and fit on a rack. I maintained the same ratio for tiles and plywood.

 

You want to keep the size square on whatever size used to avoid imbalance/lopsided components.

 

You prob won't find the tile needed at the Home Depot's. From my experience a tile shop of some sort are your best odds. If you order online there are an abundance of choices, but you won't know what you get until its delivered. Also you can't "tap" them to make sure they're not too ringy

 

Some of the shops that perform tile installs have a huge "scrap" pile in the back of their shop and will let you take whatever you want for free - just a thought.

 

I wouldn't use anything less than .5" thick tile, mainly for strength / density characteristics.

 

Sent from CA app

[4est]

If one is having trouble finding stone tile the correct size, there are always stone counter top fabricators. Marble is quite soft as been noted, and it often has a lot of filler. Granite might make a good alternative. It will polish smoother, and be less likely to have hairline fractures or filler.

The 20x20 reference was for for spkrs I believe? 18x18 is a size that will accommodate most components and fit on a rack. I maintained the same ratio for tiles and plywood.

 

You want to keep the size square on whatever size used to avoid imbalance/lopsided components.

 

You prob won't find the tile needed at the Home Depot's. From my experience a tile shop of some sort are your best odds. If you order online there are an abundance of choices, but you won't know what you get until its delivered. Also you can't "tap" them to make sure they're not too ringy

 

Some of the shops that perform tile installs have a huge "scrap" pile in the back of their shop and will let you take whatever you want for free - just a thought.

 

I wouldn't use anything less than .5" thick tile, mainly for strength / density characteristics.

 

Sent from CA app

[AnotherSpin]

From my experience dated back through many years I do not like marble for shelving/support. My major stand is DIY with very deaf Italian blue granite/bronze feet. Bamboo is very interesting material and would work better than many regular types of wood used in audio racks, however thick boards may play its own tricks with sound. Tried glass more than once only to confirm it doesn't play well for me. Alu is interesting, but when used as boards it may dampen the sound. What I realized with time, there are no definite rules working in every case for every component and for everyone's preferences. Many other factors, as what is floor made of (wood, tiles, etc.), carpeted or not, size of room, which type of wall construction/covering, etc., etc., are important. Different component may require different materials used for support. I use alu board on a top of alu bowls/chrome balls to support DAC, but the same is not works well to support mac mini, which I choose to have now on made to order quartz cones/bamboo board.

[Forehaven]

Just a thought, lg marble pieces one could look at are those white baking marble slabs.

[bdiament]

The 20x20 reference was for for spkrs I believe?...

 

Hi Foggie,

 

Not sure if the reference being referenced (;-}) is what I referred to (;-}) but if it is, I use 20" x 20" x 1" maple ply platforms under everything in my Enjoyyourshelf racks, which were designed to accommodate the largest components I might consider putting on them at any future date.

 

Under my speakers and subs, the size of the 1" thick platforms was made to exactly match the footprints of my Magnepans and the larger footprints of the subs. (They're roughly 19" x 19" for the Maggies and larger rectangles under the subs.)

 

I use 18" x 1.75" inner tubes under the 20 x 20 platforms on the racks. (No inner tubes under the speakers or subs, which are just on roller bearings, with 18" x 18" x 3/8" marble tiles between the rollers and the platforms.

 

I wouldn't use anything less than .5" thick tile, mainly for strength / density characteristics.

 

While .5 is fine, I would add that the tiles under my speakers, amps, and subwoofers (all heavy) are 3/8" thick, with no issues at all after a decade or more. So, if the tile is the right tile, I don't believe there is any problem at all with 3/8" thickness. At least, that has been my experience so far.

 

sig8,

I'd recommend 1" ply for the platforms over 3/4" simply because it is more rigid, and less prone to warping over time.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[bdiament]

If one is having trouble finding stone tile the correct size, there are always stone counter top fabricators. Marble is quite soft as been noted, and it often has a lot of filler. Granite might make a good alternative. It will polish smoother, and be less likely to have hairline fractures or filler.

 

Hi 4est,

 

Not sure about any claims of softness for marble. I've had marble tiles under heavy Magnepan 3.6s, 3.7s, and 3.7i's, under heavy power amplifiers, and under much heavier subwoofers for many years, with no issues, no scoring, etc.

 

Granite on the other hand, has a tendency to ring, so I'd be careful of that.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[Jud]

Relative hardness scale (from a kitchen contractor ) -

 

Soapstone 1

Slate 2.5-4

Marble 3-4

Limestone 3-4

Travertine 4-5

Sandstone 6-7

Granite 6-7

Natural Quartz 7

 

I have no idea whether travertine would suit, but looks as though it's a little harder than marble, if anyone's concerned.

[bdiament]

One thing to keep in mind is that once hardness is sufficient (to avoid denting, scoring, etc.), ringing becomes a consideration.

So going for the hardness spec alone, much like going for *any* spec alone, can take one down a needless - and often wrong - path.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[Jud]

One thing to keep in mind is that once hardness is sufficient (to avoid denting, scoring, etc.), ringing becomes a consideration.

So going for the hardness spec alone, much like going for *any* spec alone, can take one down a needless - and often wrong - path.

 

Best regards,

Barry

Soundkeeper Recordings

www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

 

Anything you say, Barry, just as long as we can give them your contact info when they see us rapping all their tile with our knuckles.

[bdiament]

Anything you say, Barry, just as long as we can give them your contact info when they see us rapping all their tile with our knuckles.

 

Hi Jud,

 

Sure! We can all ask for adjacent cells. And share basket weaving tips. ;-}

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[jabbr]

Or explain to all these online flooring sites why they have all these samples orders and returns:)

 

"No the color is fine, it just rings..."

[Daudio]

From my experience dated back through many years I do not like marble for shelving/support. My major stand is DIY with very deaf Italian blue granite/bronze feet. Bamboo is very interesting material and would work better than many regular types of wood used in audio racks, however thick boards may play its own tricks with sound. Tried glass more than once only to confirm it doesn't play well for me. Alu is interesting, but when used as boards it may dampen the sound. What I realized with time, there are no definite rules working in every case for every component and for everyone's preferences. Many other factors, as what is floor made of (wood, tiles, etc.), carpeted or not, size of room, which type of wall construction/covering, etc., etc., are important. Different component may require different materials used for support. I use alu board on a top of alu bowls/chrome balls to support DAC, but the same is not works well to support mac mini, which I choose to have now on made to order quartz cones/bamboo board.

 

 

I use 4" x 4" thin bathroom tiles above each roller device under my big electrotstats. They have a very hard and smooth glaze on the surface that contacts the SS balls. They are very cheap and easy to find. Mine were closeouts

 

I don't notice any 'hardness' in the upper regions of my SQ, so I'm content with them for now. I also have a set of those porcelain dollhouse platters on order*, and just may try them under my subwoofers.

 

 

* via a slow boat from Thailand

[jabbr]

I also have a set of those porcelain dollhouse platters on order*,

 

* via a slow boat from Thailand

 

Ours must be in the same boat

[Daudio]

I use 4" x 4" thin bathroom tiles above each roller device under my big electrotstats. They have a very hard and smooth glaze on the surface that contacts the SS balls... may try them under my subwoofers.

 

I had an interesting experience tonight !

 

I was listening to some heavy subwoofer bass in Tosca's 'Oscar' (Ultra Chilled 4) with a healthy volume, and noticed my floor was vibrating with the bass notes (it is a 1920's floor, suspended over a basement). I could feel it clearly through my feet, which I find enjoyable with this type of music !

 

But, when I touched the roller isolated speakers... nothing... well, a very little on the lower frame rails, where the sub fires directly thru the stat frame. But the base plate and other areas of the frame were quiet and still to the touch, and I could easily feel the floor vibrate !

 

I assume that the floor vibrations I felt were vertical. That is, the floor moving up and down in response to air pressurization changes in the room. But I don't have anything like an air bladder under my 'stats, only roller devices, thought to only operate in with horizontal vibrations.

 

So our, kind of binary, theory of roller vs. bladder device operations, doesn't seem to exactly jib with my observations. Of course I could be missing something here ? What do you guys think ?

 

 

My two 12" servo subs are presently sitting flat on the carpet, and are coupling energy into the floor. This is only a temporary situation due to having to replace one of them, and they are awaiting being re-floated on rollers when the stars align

[bdiament]

I had an interesting experience tonight !

 

I was listening to some heavy subwoofer bass in Tosca's 'Oscar' (Ultra Chilled 4) with a healthy volume, and noticed my floor was vibrating with the bass notes (it is a 1920's floor, suspended over a basement). I could feel it clearly through my feet, which I find enjoyable with this type of music !

 

But, when I touched the roller isolated speakers... nothing... well, a very little on the lower frame rails, where the sub fires directly thru the stat frame. But the base plate and other areas of the frame were quiet and still to the touch, and I could easily feel the floor vibrate !

 

I assume that the floor vibrations I felt were vertical. That is, the floor moving up and down in response to air pressurization changes in the room. But I don't have anything like an air bladder under my 'stats, only roller devices, thought to only operate in with horizontal vibrations.

 

So our, kind of binary, theory of roller vs. bladder device operations, doesn't seem to exactly jib with my observations. Of course I could be missing something here ? What do you guys think ?

 

 

My two 12" servo subs are presently sitting flat on the carpet, and are coupling energy into the floor. This is only a temporary situation due to having to replace one of them, and they are awaiting being re-floated on rollers when the stars align

 

Hi Dave,

 

Why assume the floor vibrations you felt were vertical?

If the waves were moving horizontally along the floor, that *might* explain why the roller-isolated speakers did not respond.

(It may *see* vertical if looking at a small, separate section of floor as the waves pass by. I don't know. Just speculating.)

 

I don't know in which plane the floor vibrations were moving. The speakers are coupled to the floor in the vertical plane but isolated in the horizontal (and rotational) planes. Particularly in view of the speakers' non-response, I would ask "why assume they were vertical?"

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[Foggie]

Hi Foggie,

 

Not sure if the reference being referenced (;-}) is what I referred to (;-}) but if it is, I use 20" x 20" x 1" maple ply platforms under everything in my Enjoyyourshelf racks, which were designed to accommodate the largest components I might consider putting on them at any future date.

 

Under my speakers and subs, the size of the 1" thick platforms was made to exactly match the footprints of my Magnepans and the larger footprints of the subs. (They're roughly 19" x 19" for the Maggies and larger rectangles under the subs.)

 

I use 18" x 1.75" inner tubes under the 20 x 20 platforms on the racks. (No inner tubes under the speakers or subs, which are just on roller bearings, with 18" x 18" x 3/8" marble tiles between the rollers and the platforms.

 

 

 

While .5 is fine, I would add that the tiles under my speakers, amps, and subwoofers (all heavy) are 3/8" thick, with no issues at all after a decade or more. So, if the tile is the right tile, I don't believe there is any problem at all with 3/8" thickness. At least, that has been my experience so far.

 

sig8,

I'd recommend 1" ply for the platforms over 3/4" simply because it is more rigid, and less prone to warping over time.

 

Best regards,

Barry

Soundkeeper Recordings

www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

 

Hey Barry,

 

Yeah I thought the 20x20 was the spkr platform, but just measured my "base" which is 22" > rollers > 18x18 tile > 18x18 plywood. So I stand corrected.

 

For some reason I was thinking you had a two wide rack, which of course you don't.

 

Good to know on the 3/8" thick tiles. I guess I was error'ing on the side of caution and what was posted with regards to spkr tile thickness. Sitting in the MLP and seeing spkrs on tile is just, well a little nerve racking I used the spare (scraps) from the plywood cuts and put underneath the tile - which leaves just enough gap (1/32) just "in case"

 

Rig is sounding so damn good Barry! The disappearing act is in full force - no sound is coming from spkrs

[bdiament]

...For some reason I was thinking you had a two wide rack, which of course you don't....

 

Hi Foggie,

 

That is correct. I made two racks but each is single-wide -- the shelves can easily hold a component that is a bit over 20" wide by 20" deep and close to a foot tall.

I made two because I wanted each component to have its own shelf. (However, the shelf with the power distribution block also has the power supply for the converters on it.)

 

Rig is sounding so damn good Barry! The disappearing act is in full force - no sound is coming from spkrs

 

Excellent! It is always great to hear success stories from fellow music and audio enthusiasts.

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[Daudio]

Why assume the floor vibrations you felt were vertical?

If the waves were moving horizontally along the floor, that *might* explain why the roller-isolated speakers did not respond.

(It may *see* vertical if looking at a small, separate section of floor as the waves pass by. I don't know. Just speculating.)

 

I don't know in which plane the floor vibrations were moving. The speakers are coupled to the floor in the vertical plane but isolated in the horizontal (and rotational) planes...

 

Barry,

 

Why assume ? Well, at the time that is how it felt (in my head, not skin). I visualized the air in the room oscillating in pressure, which pushed/pulled against all the walls, including the ceiling and flexible floor. Think of a balloon with a pulsing pressure from a voice coil driven 'pump', now square off the sides of the balloon and stiffen up the skin/walls. My walls are brick, tile, mostly plaster & lathe, and load bearing, but the floor is hardwood on big old(1920) joists, and likes to play the role of a trampoline (I used to tip-toe around while playing LP's before putting in your suggested air bladders under the TT) I sew that pressure pushing (and pulling) on the floor in a vertical direction.

 

Also, both subwoofers lay flat on the floor with about 1.8 ft2 of contact area each. Again a vertical energy transfer, from the bottom of the sub to the top surface of the floor (actually carpet).

 

But as I just said, this is how my brain visually modeled the 'situation', no electronic instruments were involved And I explicitly said 'assume' in the post, because I realized what I said did not come out of a book, footnote, or paper. I was guessing, but an educated guess. I've studied mechanical engineering and read more then a few books on acoustics, and have a handy 'physical dimension to frequency range' chart, not to mention being very familiar with my living rooms acoustical nature. I do some of my best thinking visually, so I think I'm close, but couldn't prove it.

 

But now I have to amend my earlier excitement. What I was doing to try and feel these low frequency vibrations, was to lightly touch the surfaces with the tips of my fingers, supposedly for the max sensitivity. I didn't feel much vibration. and posted about that. A little later on, I discovered that I needed to get a tight grip on the edges, or press hard against a surface to feel those low vibrations. Done plenty of 'rapping to reveal rings', and light touches for hums, but either forgot, or just found this technique.

 

So, back to the speaker to retest, and the vertical frame vibrated a good deal, both from the sub waves from behind, and it own, somewhat higher bass production. But the flat base plate was still pretty dead, except under the vertical rails. I noticed an interesting difference in some of the vibrations. One of the electronic tracks had heavy bass activity below 80hz, the crossover freq. twixt my subs and stats. Another track had a different bass, just as heavy, but higher, and I could feel it much more in the middle of the stat frames as the panels they supported were pulsating to produce that sound. When the sub was the doing the bass, I could feel it being transferred to the lower frame rails from the subs cone, 2 feet behind them.

 

It was fun playing around for a while, but at this point, I don't know what all this means, if anything. But, I did learn (relearn?) something

 

 

FWIW - I've had two experience that may, or may not lend anything to this question.

 

Once, in a large semi-cylinderical roofed building I was at a trance concert (Sasha & Digweed). The dance area was defined by 6 large speaker stacks (maybe 8' x 12'), containing a rectangle covering about 75% of the 'floor'. When the music really got going, I found to my delight, that the 4"-6" of air directly above the surface of the floor, simply 'throbbed' with bass energy ! But you could only feel it if your feet were off the floor. (too bad the music just wasn't that danceable , not many people were, nor I unfortunatly)

 

Another time with a system consisting of BG RD-75's, BIG box woofers, and (4-6 ?) in-wall, plenum mounted, sub drivers. A CD of a NASA shuttle launch rattled my pant cuffs and ankles in the same relative height region.

 

 

I hope I have raised more questions then answers

[jabbr]

The ceramic bowls and plates have arrived from Thailand. They are porcelain. The photos demonstrate that the ball bearings slide to the edges of the plates. Obviously the platform isn't perfectly leveled. But that is realistic. I don't think the bearings are in the linear part of the plates and thus these won't be an ideal vibration isolation platform. The bowls are OK but aren't perfectly spherical. I think that ceramic bowls could be further investigated but would need to be produced to a more exact specification.

[Tintinabulum]

Slightly off topic but on the subject of isolation, vibration etc, how much harm are humming transformers going to do to ones sound? Presumably there's a lot of vibration caused, is this going to be significantly impacting SQ (apart from about as long as a piece of string)? This is leading to- how much effort to I put into resolving this (balanced transformer, move home..)? Ta.

[sig8]

An 18" tube blows to a 23" ring, I just pumped air in one, is that the idea? It is too big for a 22"x22" plywood. I don't think we intend to have plywood smaller than the tube.

 

May be I should use 16" tube, which might blow to 21", and then 22"x22" ply might be ok.

[Daudio]

An 18" tube blows to a 23" ring, I just pumped air in one, is that the idea? It is too big for a 22"x22" plywood. I don't think we intend to have plywood smaller than the tube.

 

If the inner tube pokes out a little under the sides of your plywood plate, I wouldn't be too worried about it. I have one that buldges out a little under a BDR Shelf. As long as the top, load bearing, portion of the tube is in contact with the plate, I'd be happy.

 

Did you fully inflate your 18" tube to see those dimensions ? Remember it should only be partially inflated. Just enough to lift the load above the level of the tubes's stem. Maybe that will bring the diameter down some ?