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Best way to make a fiddle quieter?


bean_fidhleir

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Was that a high sensitivity rubber, or standard issue? 1mm seems pretty heavy duty... :)

Standard white rubber band. It might be a little thinenr than 1mm. In theory the vibration insulation one get from the static deflection should give an insulating effect from about 15.8/squareroot(deflection in mm) Hz. Wich for this 1mm, or slightly less, piece should be some 50Hz. (This is theory based on deflection from the insulating mass own wheight, as used for vibration insulation of machinery etc). What I got was a reduction in sound output in a band from some 800Hz up to about 1,5kHz or so. Sort of a weak "notch filter".

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Anders, have you tried using snippets of rubber as buffers between the strings and the bridge?

I thought of putting slices of rubber band under the feet, but thought it might well destabilise the bridge, perhaps causing it to fall over, and would at the very least have a bad effect on the varnish. I take it those weren't problems that you saw in practice?

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Anders, have you tried using snippets of rubber as buffers between the strings and the bridge?

I thought of putting slices of rubber band under the feet, but thought it might well destabilise the bridge, perhaps causing it to fall over, and would at the very least have a bad effect on the varnish. I take it those weren't problems that you saw in practice?

No, have never tried that. Will they hold? The pressure per area will be very large then on the rubber.

Do not think the varnish is harmed by the rubber band pieces. The stability problem might be an effect to take into account if it is used over a certain time. Would need to look after the bridge being straight up.

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I just now installed the slices, taken from a natural (uncolored) rubber band that's somewhere between 1.5 and 2.0 mm thick (I've an engine-divided steel ruler, but the division marks are of appreciable thickness, so I can't be certain at such a small size - it looks like 2.0) and 15mm wide.

I don't have any testing equipment, but when bowed the fiddle does seem to have been damped approximately equally across all strings.

Of course, without equipment I've no way of telling how large the effect is. It doesn't seem especially large under the ear, but perhaps it's more than I think. I'm thinking that perhaps I could increase the effect by sliding a length of shrinkable electrical insulation tubing over the strings, to distribute the pressure a bit more.

If you think it's worthwhile trying as an experiment, I hope you'll let us know the measurements you get, since you do have the requisite equipment.

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I can't think of any method that would reduce sound without affecting tone. Adding flexibility between the string and instrument is a classic frequency filter.

The best and cheapest solution would be to get a batch of soft foam earplugs, and give them out to all of the nieghbors within earshot. :)

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Standard white rubber band. It might be a little thinenr than 1mm. In theory the vibration insulation one get from the static deflection should give an insulating effect from about 15.8/squareroot(deflection in mm) Hz. Wich for this 1mm, or slightly less, piece should be some 50Hz. (This is theory based on deflection from the insulating mass own wheight, as used for vibration insulation of machinery etc). What I got was a reduction in sound output in a band from some 800Hz up to about 1,5kHz or so. Sort of a weak "notch filter".

Here is the curve. Green: Normal violin, Blue: bridge with rubber pieces under the bridge feet. There is also a curve from the violin played with wedges pushed into the cutouts in the bridge.

The rubber band experiment is interesting as there should really have been a roloff all the way from the start of the effect to the high frequencies. Wonder if there is "leaking" sound via the tailpiece or the nut end of the string. Wit a smarter design of the experiment one could asess the effects of sound transmitted via the nut end and the tailpiece. By theory they should be small, but who knows?

post-25136-1233520858_thumb.jpg

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Here is the curve. Green: Normal violin, Blue: bridge with rubber pieces under the bridge feet. There is also a curve from the violin played with wedges pushed into the cutouts in the bridge.

The rubber band experiment is interesting as there should really have been a roloff all the way from the start of the effect to the high frequencies. Wonder if there is "leaking" sound via the tailpiece or the nut end of the string. Wit a smarter design of the experiment one could asess the effects of sound transmitted via the nut end and the tailpiece. By theory they should be small, but who knows?

I think the filtering the rubber band pieces under the feet will change somewhat with the amount of pressure the bridge applies against the belly, thus changing the compression against the rubber. The more compressed, the less dampening or isolation. However I don't know if this parameter that would exhibit appreciable change with the narrow range of pressure differences from one violin to the next to be worthy of consideration.

Perhaps some type of closed cell foam would work better for decoupling the bridge from the belly. Either you need the bridge working into something with enough mass to produce an acoustic dead short absorbing the energy and dispersing as heat, or something that will absorb and disperse the energy being inputed by the bridge some other efficient way resulting in minimal transfer to the belly.

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Fascinating experiment.

I am not sure closed cell foam or any other material would decouple any more effectively, due to the forces essentially squishing any compressible material(s) into that having approximately the same properties, however, greater reductions might be realized if the feet were made larger, in order to distribute the force over a greater area, thus reducing the degree of compression.

Andres, if you get a chance, it might be interesting to see if you could get damping somewhere in between the rubber and bare, say with with a layer or layers of trimmed electrical tape.

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Fascinating experiment.

I am not sure closed cell foam or any other material would decouple any more effectively, due to the forces essentially squishing any compressible material(s) into that having approximately the same properties

I have to agree this looks like an unobtainable ideal, but I thought compressing some bubbles of air might offer better decoupling, if they'll stand up to the pressure.

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