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Sorbothane for stand mounts

Katji

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#41
I use Blue Tack to mask annoying LEDs on the fronts of components. I'd really like to get it in black, but I'm having trouble shopping for it because "Blue Tack" is a brand name and it's not obvious what the generic name for it is. I've managed to find some in white but not yet black. Any advice anyone please?
[In SA it's Prestik (Bostik) - I've never seen Blu-tac.] I think you won't get black. You could try coloring it with black permanent marker, or sticking a tiny piece of masking tape over it and colouring that. (If it's not the tiny pinhead-size LEDs.)

Google not showing any generic name, just "...original rubber based reusable putty adhesive"
 

Wes

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#42
I was considering this very issue, and came across this 'Sound on Sound' article that discuss the merits of de-coupling instead of coupling:

https://www.soundonsound.com/sound-advice/understanding-speaker-stands-platforms
Spikes "cause[] problems on wooden floors, due to vibrations from the speaker cabinet being transferred to the floor via the rigid stand and spikes. The floor will then act as the king of soundboards!"

1. this could be measured with an accelerometer; most phones contain one...

2. if a speaker is driving a large floor (or maybe just a board or panel in the floor) a "thought exp." might suggest that volume will be quite low
 

brimble

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#43
2. if a speaker is driving a large floor (or maybe just a board or panel in the floor) a "thought exp." might suggest that volume will be quite low
That was my first thought, but then I remembered that it's a magazine for recording studios, and excited rock bands sometimes play their stuff back pretty loud.
 

DSJR

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#44
being brought up (conditioned) to rigid mounting of speakers to stands to floor and having done many dems to 'prove' this method in th epast, we in the store then became worried about how spikes on top of the stands messed with the speaker cabinets (bear with me a moment longer please). We began to use these little feet between speaker and stand -

https://uk.rs-online.com/web/p/products/1735966/

They're clear, so don't stain nice veneers, they're hard enough to prevent the speakers wobbling yet soft enough to add grip and the adhesive isn't that strong you can't easily remove them later. Usually, one would put them on the top of the stands and sit the speaker on top but in the store with shelves to display the speakers on when not in use, we put them on the speaker bottoms, one on each corner. A pack is cheap too when you look at the price of isopucks and so on!

Just a suggestion. may work perfectly or may not, but you haven't lost anything. I also have sorbothane feet I used once and they've left 'scars' on painted finishes :(
 

DSJR

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#45
Spikes "cause[] problems on wooden floors, due to vibrations from the speaker cabinet being transferred to the floor via the rigid stand and spikes. The floor will then act as the king of soundboards!"

1. this could be measured with an accelerometer; most phones contain one...

2. if a speaker is driving a large floor (or maybe just a board or panel in the floor) a "thought exp." might suggest that volume will be quite low

Bottom spikes into wooden floor boards - We were told in the early 80's to put crosshead screws into the floor for the spikes to sit in... Later, spike 'shoes' could be got to save harming said floors and if you were really keen, it was suggested to put solidly attached MDF 'islands' in place to reduce any excessive vibration.

These days, the new fashion is to decouple everything, from a pickup cartridge to tonearm (Funk Houdini) and speakers from stands and floor, adding in many suspect compliances which may or may not do good. I have to confirm my prejudice as to me at the time, it was eaasy to demonstrate the reduced focus and clarity by having speakers wobbling around on the carpet. I'm getting too old for this I suspect :(
 

Harmonie

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#47
I use Blue Tack to mask annoying LEDs on the fronts of components. I'd really like to get it in black, but I'm having trouble shopping for it because "Blue Tack" is a brand name and it's not obvious what the generic name for it is. I've managed to find some in white but not yet black. Any advice anyone please?
If just the leds you wish to hide in Black, you can try with Black nail polish and take it off very carefully with some Acetone or less aggressive dissolvent
 
Last edited:

SIY

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#48
[In SA it's Prestik (Bostik) - I've never seen Blu-tac.] I think you won't get black. You could try coloring it with black permanent marker, or sticking a tiny piece of masking tape over it and colouring that. (If it's not the tiny pinhead-size LEDs.)

Google not showing any generic name, just "...original rubber based reusable putty adhesive"
"Mounting putty."
 

UCrazyKid

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#49
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#50
If decoupling is what you want, you could get some of these hanging flower pot nets. I’d be surprised if some “audio” company isn’t turning these out for $1000 each.
View attachment 110861 [/QUOTE

Actually if you dive into the IsoAcoustics website, I believe they tried just that. They suspended speakers by bungee cords or similar, and took measurements before and after. Full suspension (complete de-coupling). actually did worse; they concluded that the cabinet/driver assembly needed something to 'push' against in order for drivers to function properly. If one wants to dive deep into this sort of thing, I think it actually gets pretty interesting and not always what we might expect. Newton's laws continue to apply.
 

NTK

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#52
Actually if you dive into the IsoAcoustics website, I believe they tried just that. They suspended speakers by bungee cords or similar, and took measurements before and after. Full suspension (complete de-coupling). actually did worse; they concluded that the cabinet/driver assembly needed something to 'push' against in order for drivers to function properly. If one wants to dive deep into this sort of thing, I think it actually gets pretty interesting and not always what we might expect. Newton's laws continue to apply.
Not exactly. Bungee cords measured better. They have to resort to the voodoo of (uncontrolled?) listening test to provide the "proof". That basically defeat the whole point of measurement.

IsoAcoustics.JPG


[Edit] Unsurprisingly, their analysis of their NRCC measurements was totally non-existing. There was nothing to indicate whether any of the cabinet vibrations had any audible effects. What they should have done is to integrate the surface vibration velocity (shown in the graph), over the entire speaker cabinet, considering the phase differences (because each point on the cabinet surface will move differently), and to compute its acoustic radiation in 3D, using boundary element methods (BEM).
 
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Harmonie

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#53
I remember about 2 or more decades ago, there were some German geometric string designs set-ups which function was like elastic bands to decouple the vibration of audio gear.

a bit like below idea

1612734413629.png
 
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#54
Not exactly. Bungee cords measured better. They have to resort to the voodoo of (uncontrolled?) listening test to provide the "proof". That basically defeat the whole point of measurement.

View attachment 111039

[Edit] Unsurprisingly, their analysis of their NRCC measurements was totally non-existing. There was nothing to indicate whether any of the cabinet vibrations had any audible effects. What they should have done is to integrate the surface vibration velocity (shown in the graph), over the entire speaker cabinet, considering the phase differences (because each point on the cabinet surface will move differently), and to compute its acoustic radiation in 3D, using boundary element methods (BEM).

When I go back and read their investigation, I agree that they could have (and should have?) been more thorough about how they executed. I get it that they are a for-profit company and have a product to sell. But I don't think that means the overall concept of speaker decoupling should be dismissed. I think it's totally worth further exploration. To me it makes sense: if a speaker is vibrating, where do the resonances go? Might some resonances rattle inside the enclosure, and mess with the intended vibration of the drivers? Or resonate down onto whatever surface they are touching, which cause other unwanted sound transduction? etc.

Although far from a perfect example, here's a non-audio one: chainsaws.

Years ago I used to cut trees and turn into firewood. Chainsaws vibrate, A LOT, lol. Those vibrations then go into your hands and arms, causing human wear & tear, and user fatigue. Repeat that for hours on end, or repeated use, and gets old. The German company Stihl, started making their chainsaws with anti-vibrational decouplers installed at what they determined were transitional joints within the saw. I can tell you from personal experience of switching to one of their updated saws, it made a very big difference for the end user.

I think this same concept can be extrapolated to the speaker / stand / room interface (s). Eliminate unexpected / unwanted resonance & vibration at the speaker, as much as possible, so that the drivers can do their job as designed, and send those resonances into the air. I have no idea what the best material or method is, to make that happen. I don't think anyone does. But I think experimenting with Sorbathane, 'foam sandwich', half squash -balls, or whatever, is worth pursuing.
 

Blumlein 88

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#55
When I go back and read their investigation, I agree that they could have (and should have?) been more thorough about how they executed. I get it that they are a for-profit company and have a product to sell. But I don't think that means the overall concept of speaker decoupling should be dismissed. I think it's totally worth further exploration. To me it makes sense: if a speaker is vibrating, where do the resonances go? Might some resonances rattle inside the enclosure, and mess with the intended vibration of the drivers? Or resonate down onto whatever surface they are touching, which cause other unwanted sound transduction? etc.

Although far from a perfect example, here's a non-audio one: chainsaws.

Years ago I used to cut trees and turn into firewood. Chainsaws vibrate, A LOT, lol. Those vibrations then go into your hands and arms, causing human wear & tear, and user fatigue. Repeat that for hours on end, or repeated use, and gets old. The German company Stihl, started making their chainsaws with anti-vibrational decouplers installed at what they determined were transitional joints within the saw. I can tell you from personal experience of switching to one of their updated saws, it made a very big difference for the end user.

I think this same concept can be extrapolated to the speaker / stand / room interface (s). Eliminate unexpected / unwanted resonance & vibration at the speaker, as much as possible, so that the drivers can do their job as designed, and send those resonances into the air. I have no idea what the best material or method is, to make that happen. I don't think anyone does. But I think experimenting with Sorbathane, 'foam sandwich', half squash -balls, or whatever, is worth pursuing.
Sorbothane is good material as it turns 90% of shock energy into heat.

Typically you need something like automotive suspensions. Springs which give away during shock, and hydraulic dampers to absorb and turn that energy into heat while letting the springs return the suspension to its original position after the shock. Sorbothane is maybe the only material or one of a few that has all the properties to act like the springs and the shocks in one compound.
 
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#56
The first thing I tried to decouple my desktop speakers from the desk was yoga blocks, but they didn't do much other than raise the speakers so that the tweeters were at ear level. I read about sorbothane pads, but before spending the money, I thought I'd try something that I could find at home that felt something like sorbothane. I found the insoles of my old running shoes that had a gel pad under the heel, so I cut the gel pads into pieces and put them between the speakers and the yoga blocks. That was it! Clearly audible difference. I could even feel with my hands that the desk didn't vibrate as much. 80% solution for free.
 

NTK

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#57
When I go back and read their investigation, I agree that they could have (and should have?) been more thorough about how they executed. I get it that they are a for-profit company and have a product to sell. But I don't think that means the overall concept of speaker decoupling should be dismissed. I think it's totally worth further exploration. To me it makes sense: if a speaker is vibrating, where do the resonances go? Might some resonances rattle inside the enclosure, and mess with the intended vibration of the drivers? Or resonate down onto whatever surface they are touching, which cause other unwanted sound transduction? etc.

Although far from a perfect example, here's a non-audio one: chainsaws.

Years ago I used to cut trees and turn into firewood. Chainsaws vibrate, A LOT, lol. Those vibrations then go into your hands and arms, causing human wear & tear, and user fatigue. Repeat that for hours on end, or repeated use, and gets old. The German company Stihl, started making their chainsaws with anti-vibrational decouplers installed at what they determined were transitional joints within the saw. I can tell you from personal experience of switching to one of their updated saws, it made a very big difference for the end user.

I think this same concept can be extrapolated to the speaker / stand / room interface (s). Eliminate unexpected / unwanted resonance & vibration at the speaker, as much as possible, so that the drivers can do their job as designed, and send those resonances into the air. I have no idea what the best material or method is, to make that happen. I don't think anyone does. But I think experimenting with Sorbathane, 'foam sandwich', half squash -balls, or whatever, is worth pursuing.
I agree that it is very sensible to isolate the speaker from the floor to prevent the transfer of the vibration energy into the building structure. What I have problem with is the pretension that there is valid scientific basis behind IsoAcoustics' claim of its products' superiority.

Some back of the envelop calculations — referencing materials from Linkwitz (RIP).

linkwitz.JPG

Radiating area (A):
Assume the speaker is rocking front and back, and the front and back cabinet walls are 3 ft tall and 1 ft wide, the total radiating area is 6 ft^2 = 0.5574 m^2.

RMS velocity (v):
Assume the graph reported RMS velocity instead of peak, and consider the 2 highest peaks at ~270 Hz and ~450 Hz. The cabinet wall velocities for spikes were 7.7e-6 and 4.6e-6 m/s, respectively.

RMS volume velocity (U) is radiating area times RMS velocity (i.e. U = A * v).

Density of air (q) is 1.19 kg/m^3.

Assume speaker to listener distance (r) is 2 m.

At 270 Hz, p = U * q * f / (2 * r) = (7.7e-6 * 0.5574) * 1.19 * 270 / (2 * 2) = 0.000345 Pa → 24.7 dB SPL.
At 450 Hz, p = U * q * f / (2 * r) = (4.6e-6 * 0.5574) * 1.19 * 450 / (2 * 2) = 0.000343 Pa → 24.7 dB SPL.

During the test, the speaker was outputting 90 dB SPL (at an unreported distance). Assuming it was 1 m, even with a 6 dB distance attenuation at the 2 m listening distance, the signal to sound from speaker cabinet vibration ratio was still a very healthy ~60 dB.
 

Helicopter

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#58
I would put sorbothane under a silicone baking mat and trim.

On my listening room floor, carpet on cork on concrete, I use spikes. In the rest of the house, wood over a basement, I decouple.
 
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