Not to diminish your efforts, but you probably made things worse because a W26FX002 will probably never audibly excite that resonance when used over a reasonable bandwidth, but reducing the cabinet volume sure will cause an audible deficit.
Reasonable compromises are needed everywhere, otherwise there's nothing stopping you building everything out of 2ft thick concrete with titanium rebar.
Boden:
There is some sikaflex products ( look at their marine range of products, maybe the one linked by Diyiggy too i don't remember reference).
3m should have some products of interest ( the thing they use to dampen hdd).
Look for products like 'sound barrier' from Auralex. MLV family of material ( Mass Loaded Vinyl).
Earl Geddes used melamine glue as shear layer in his CLD bracing.
Maybe worth looking at Augerpro's thread about box construction technique too, there is example of CLD.
One thing with glue/gel product one should be aware before choosing it is it's messy and not easy ( well for me!).
Member's Bon documented a ( impressive!) build like that and steps are shown:
https://www.diyaudio.com/community/...ligned-constrained-layer-construction.218437/
There is some sikaflex products ( look at their marine range of products, maybe the one linked by Diyiggy too i don't remember reference).
3m should have some products of interest ( the thing they use to dampen hdd).
Look for products like 'sound barrier' from Auralex. MLV family of material ( Mass Loaded Vinyl).
Earl Geddes used melamine glue as shear layer in his CLD bracing.
Maybe worth looking at Augerpro's thread about box construction technique too, there is example of CLD.
One thing with glue/gel product one should be aware before choosing it is it's messy and not easy ( well for me!).
Member's Bon documented a ( impressive!) build like that and steps are shown:
https://www.diyaudio.com/community/...ligned-constrained-layer-construction.218437/
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Hi Krivium, the Sika marine range is a little less good for our hobby, cause it is less elastic (while still is) and is mostly made to work better on plastic and hard joint between parquet. The 11FC however is more elastic while very strong on multiple support with very very low air emission (european norms for inside home using). I used it for a cabinet... much better than wood glue and as strong while staying (micro) elastic. It is also cheaper than the marine range and easier to source (Lee Roy Merlin for instance or Amazon 
). Very better than wood glue for sealing purpose also... I used it for car, lol !
Just my 2 cents.
). Very better than wood glue for sealing purpose also... I used it for car, lol !Just my 2 cents.
Yes i see your point but the performance relative to shear properties are not totally linked to 'elasticity'. Or silicone would suffice...
I can't remember the parameter to look for atm, neither the ref of the marine product ( iirc it is a PU glue used for decks assembly/repair).
Something like sorbothane ( metamaterial) could be used too to great effectiveness.
Here is the kind of behavior you are looking for ( courtesy of Xrk971):
Anyway there is a range of products availlable for experiments.
(PS: in Bon's thread linked he gives a simple way to evaluate CLD , same way as Xrk's video).
I can't remember the parameter to look for atm, neither the ref of the marine product ( iirc it is a PU glue used for decks assembly/repair).
Something like sorbothane ( metamaterial) could be used too to great effectiveness.
Here is the kind of behavior you are looking for ( courtesy of Xrk971):
Anyway there is a range of products availlable for experiments.
(PS: in Bon's thread linked he gives a simple way to evaluate CLD , same way as Xrk's video).
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the basis is the same: elastic polurethan glue. for the shear effect, one layer must move, hence the thre layers cld layers bracing of one of the link you provided above when couplling i needed between walls or free thin layer than vibrate when there is only one layer decoupled inside that is not touching the surroundings (so freely glied on the cabinet walls à la OSMC cabinet with thin layer (ideally under the mm if I understood the readings of cld technic here and there for cars and planes, while I dunno the frequencies involved there). That glue is impressive, you can't not move of course two layers glued with it by hands... but it stays "flexible, "elastic" enough to allow the needed mvt.
The marine Sicaflex can be sanded so is relativly harder than the 11FC that is more lossy.
Then the properties of the layers seems important too
The marine Sicaflex can be sanded so is relativly harder than the 11FC that is more lossy.
Then the properties of the layers seems important too
They have//had a whole lineup, of anti vibration/shock products. E-A-R / Aearo technologies.
And indeed they are used for HDDs amongst other things.
Isoloss and isodamp, from different sheets and compositions, gaskets, anti vibration mounts, grommets, fan mounts, feet etc. Also foams (isoloss) and some other alernatives.
If you're willing to buy in large enough quantities, they will also custom mould products for a specific app.
The isodamp sheets suitable for CLD comes in thicknesses from 0.1 " to 1" in standard ranges, the price is generally what puts people off.
https://www.rathbun.com/e-a-r/damping-isolation
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May be something like this would work:
EVERBUILD® BLACK JACK® 908 D.P.M. | Bitumen & Roofing Products
I use it to paint the inside of my speakers with and to fix any damping material etc. Smells a bit when applying but dries into an odourless layer of rubber.
It requires plasticity(convert mvmnt to warmth) that is tuned for the stiffness of the two layers. At least if the objective is to dampen structure borne vibrations and panel resonances.
Elastic materials are ment for isolation ie no conductance of structure borne vibrations.
Sorbothane to my knowledge originally was ment for "isolating" submarines , ie reflecting like water thus invisible.
For isolation it works very well, i used it in the past for isolating record players.
It is not clear to me how should be sized this "elastic" layer. Too much thick like several mm : typicaly around 5 mm with a very thin aluminium layer (roof, building plateau isolation) seems not so fantastic. The bitumenn layer should be within the mm and the cover that also need to vibrate for the shear effect transmission should be also thin but stiff (which the aluminum bitumen pas in rolls are not) ?
Also the elastic glue are very hard to apply in thin layers and very sticky by nature... I found it hard to do for the loudspeakers panels without a plain press plan... which virtually noone has at home.
In my main loudspeaker, inside surface but where the bracings are, is surfaced with 6 mm strong thick bitumen pads that are almost not flexible. Ok it gives at mat sound when yoy knowck on the outside loudspeaker surface... but I think it is jjustt adding weigth finally at reading here and there some inputs.
What do you think?
Damping happens due to shear in the middle layer, glue. Imagine the whole panel flexing outward on the center on the lowest mode for example: inner surface of the outer layer contracts while outer surface of the inner layer expands, and the elastic layer between is now subject to shear force which is utilized here as dampening.
If the layer in between is too thich I would imagine intuitively the inner and outer layer would act independently, shearing force vectors would have larger angle and lessor effect (picturing it in my forehead, not expert on this). After all the bending / vibration of the panels is quite small in magnitude and to keep shear max use as thin layer as possible. One would want as much of the shear force in the middle layer as possible, expanding and contracting surfaces as close together as possible.
I used local construction adhesive with proper shore number (which I've already forgotten, the surface of that skinned quite fast so glueing big panels would be difficult with that particular stuff. I applied it as a bead and planed it with small piece of plywood, which makes quite a thin layer. One could 3D print a comb to apply optimal thickness. Not sure what that would be, print few, do tests and compare.
Anyway, 6mm ply layers and thin layer glue in between made quite a difference, dampens nicely, but not sure if its optimal or anything. Anyway, small panels glued inside box walls like in op video seem to work fine also in my experiments few yeas back.
edit. it was kiilto masa, shore A 40
If the layer in between is too thich I would imagine intuitively the inner and outer layer would act independently, shearing force vectors would have larger angle and lessor effect (picturing it in my forehead, not expert on this). After all the bending / vibration of the panels is quite small in magnitude and to keep shear max use as thin layer as possible. One would want as much of the shear force in the middle layer as possible, expanding and contracting surfaces as close together as possible.
I used local construction adhesive with proper shore number (which I've already forgotten
, the surface of that skinned quite fast so glueing big panels would be difficult with that particular stuff. I applied it as a bead and planed it with small piece of plywood, which makes quite a thin layer. One could 3D print a comb to apply optimal thickness. Not sure what that would be, print few, do tests and compare.Anyway, 6mm ply layers and thin layer glue in between made quite a difference, dampens nicely, but not sure if its optimal or anything. Anyway, small panels glued inside box walls like in op video seem to work fine also in my experiments few yeas back.
edit. it was kiilto masa, shore A 40
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Wonder about a three layers CLD axith in between layer in steel, aluminium, so stiff but thin -1 mm max- The two outsides layers made of wood. Could be important that layer to be stiff ad made of metal for the heat loss efficienty ?
When you see modern loudspeakers à la Magico madeof aluminum everywhere, they are ultra stiff but do not use CLD at all, no ?
When you see modern loudspeakers à la Magico madeof aluminum everywhere, they are ultra stiff but do not use CLD at all, no ?
Page 157 and 158 of the ARTA manual give a summary of a study performed by Thomas Ahlersmeyer. ’nuff said about bitumen vs glue.
^^Hi, I have no idea, looked magico website and it seems to be marketing and differentation to my eye, they probably sound fine, never heard.
About thin layers: their surfaces don't expand and contract as much as thick for same curvature. Think you bent a panel to a circle, the thicker the panel the more length difference between the outer and inner surface because difference in radius. Can't bend thick ply by hand because of this, the outer side would easily rupture if you had enough power to do it. But paper or any other relatively thin sheet of any material bends no problem, or if the material streches/compresses without damage, like a matress. I'm not sure if such material was good with cld panel, haven't tought it further, or studied it
About thin layers: their surfaces don't expand and contract as much as thick for same curvature. Think you bent a panel to a circle, the thicker the panel the more length difference between the outer and inner surface because difference in radius. Can't bend thick ply by hand because of this, the outer side would easily rupture if you had enough power to do it. But paper or any other relatively thin sheet of any material bends no problem, or if the material streches/compresses without damage, like a matress. I'm not sure if such material was good with cld panel, haven't tought it further, or studied it
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