Damping Mechanical Energy Distortion of STAX and other phones with SORBOTHANE and other materials.
Nov 24, 2017 at 1:33 PM Post #901 of 952
According to manufacturer, sorbothane can also be used for acoustic isolation and absorpbtion. I don´t remember this being mentioned on this thread.

Sorbothane® has wide applications in:

  • Shock absorption in industrial, electronic, athletic and medical applications
  • Vibration isolation in industrial, electronic and ergonomic applications
  • Vibration damping in industrial, electronic and ergonomic applications
  • Gasket/sealing in industrial and electronic applications
  • Applications where low cost, high color plastic molding is required
  • High-space-efficiency acoustic absorption
  • High-space-efficiency acoustic barriers
https://www.sorbothane.com/material-properties.aspx
 
Nov 24, 2017 at 8:29 PM Post #902 of 952
According to manufacturer, sorbothane can also be used for acoustic isolation and absorpbtion. I don´t remember this being mentioned on this thread.

Sorbothane® has wide applications in:

  • Shock absorption in industrial, electronic, athletic and medical applications
  • Vibration isolation in industrial, electronic and ergonomic applications
  • Vibration damping in industrial, electronic and ergonomic applications
  • Gasket/sealing in industrial and electronic applications
  • Applications where low cost, high color plastic molding is required
  • High-space-efficiency acoustic absorption
  • High-space-efficiency acoustic barriers
https://www.sorbothane.com/material-properties.aspx

I can see it as a barrier. I am not sure what they mean by acoustic absorption which is different from vibration damping, acoustic and otherwise. Did you find an example?
 
Nov 24, 2017 at 8:35 PM Post #903 of 952
This is a set-up for my old portable cd player. 1/4 inch 70 duro on the base with 4 layers of electrical tape to provide constrained damping. Then 4 1/0 inch 70 duro pieces on the plug going into the player with tape wrapped. And of course damping on the phones, 1/10 70 duro behind the driver unit and 1/2 70 duro on the headband. Amazingly good sound. I can not stand mp3 sound.

1/2 inch is good if you can fit it where needed. Here I used my expensive Lord adhesive because I cannot find 1/2 with 3m self-stick. Unfortunately my can of glue dried out.
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Nov 29, 2017 at 12:28 AM Post #906 of 952
The link posted above to the Sorbothane Company site distinguishes between isolation and damping. It gives the example of spring or rubber mounts which can be effective isolators but ineffective at damping. I would add that car springs are very good for when your car hits a bump, but requires a shock absorber to dampen down the oscillations cause by the impact. Sorbothane appears to be more like a shock absorber, getting rid of energy by coverting it to heat. Here it is again. https://www.sorbothane.com/material-properties.aspx
 
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Jan 23, 2018 at 9:27 PM Post #907 of 952
Has anyone determined if there is a difference between treating the outside of the cups and the inside in terms of effectiveness?
Does the surface of the sorbothane need to be exposed to the soundwaves directly for better effectiveness...or does simply being attached to the surface and controlling vibrations of the 'non-driver parts' matter? To put it another way....is it absorbing on it's surface AND controlling the vibrations of what it's attached to...or just the latter?
I have two different dynamic headphones that I want to try this on possibly ( I need to find some cheap sorbothane) both headphones seem fairly well designed, but not damped AT ALL compared to my Fidelio L2 for example...I am going to start with a Philips SHP 9500s and a Superlux HD681...they both sound pretty good for their price and it feels like they have tons of potential, because their flaws aren't serious.... but they are cheaply made. The Superlux especially has very thin/resonant plastic...it feels like if I can pay a little attention to the details of controlling resonances in the housing for the best sound possible, these 'budget' headphones will reproduce my music beautifully....which is the WHOLE point.
I have had good cars that can be made great by simply addressing the corners that the manufacturer cut. (it's AMAZING the difference an aluminum radiator makes over a plastic one when you are trying to autocross in the Texas heat!) and the more I look at my headphones and try to understand why one sounds better than another, it feels like too much reflection or glare coming from the housing is part of the problem. It looks like like y'all have put A LOT of thought into this (thanks guys! loooooong read lol.) but I didn't see an answer to my question...does having the surface of the sorb facing the soundwaves make a big difference, or is it more about finding the best spot on the surface of the housing?
 
Jan 23, 2018 at 9:31 PM Post #908 of 952
This was a double post.......
but I would like to add, the Superlux HD681...it sounds to me like they are nice clear drivers in a decent housing in terms of design. They are an 'homage' to the classic AKG 240 line. But the plastic they are made from is thin and brittle. I know materials, from my professional life, and the cups on these things sing with energy. I am betting that with some strategically placed sorb they will hush up and my Senilux 681s will become deadly accurate, truth telling headphones. They already have a spare, clean sort of sound, but it's like there's a little smoke in the air...
 
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Jan 24, 2018 at 3:59 AM Post #909 of 952
Has anyone determined if there is a difference between treating the outside of the cups and the inside in terms of effectiveness?
Does the surface of the sorbothane need to be exposed to the soundwaves directly for better effectiveness...or does simply being attached to the surface and controlling vibrations of the 'non-driver parts' matter? To put it another way....is it absorbing on it's surface AND controlling the vibrations of what it's attached to...or just the latter?
I have two different dynamic headphones that I want to try this on possibly ( I need to find some cheap sorbothane) both headphones seem fairly well designed, but not damped AT ALL compared to my Fidelio L2 for example...I am going to start with a Philips SHP 9500s and a Superlux HD681...they both sound pretty good for their price and it feels like they have tons of potential, because their flaws aren't serious.... but they are cheaply made. The Superlux especially has very thin/resonant plastic...it feels like if I can pay a little attention to the details of controlling resonances in the housing for the best sound possible, these 'budget' headphones will reproduce my music beautifully....which is the WHOLE point.
I have had good cars that can be made great by simply addressing the corners that the manufacturer cut. (it's AMAZING the difference an aluminum radiator makes over a plastic one when you are trying to autocross in the Texas heat!) and the more I look at my headphones and try to understand why one sounds better than another, it feels like too much reflection or glare coming from the housing is part of the problem. It looks like like y'all have put A LOT of thought into this (thanks guys! loooooong read lol.) but I didn't see an answer to my question...does having the surface of the sorb facing the soundwaves make a big difference, or is it more about finding the best spot on the surface of the housing?
Has anyone determined if there is a difference between treating the outside of the cups and the inside in terms of effectiveness?
Does the surface of the sorbothane need to be exposed to the soundwaves directly for better effectiveness...or does simply being attached to the surface and controlling vibrations of the 'non-driver parts' matter? To put it another way....is it absorbing on it's surface AND controlling the vibrations of what it's attached to...or just the latter?
I have two different dynamic headphones that I want to try this on possibly ( I need to find some cheap sorbothane) both headphones seem fairly well designed, but not damped AT ALL compared to my Fidelio L2 for example...I am going to start with a Philips SHP 9500s and a Superlux HD681...they both sound pretty good for their price and it feels like they have tons of potential, because their flaws aren't serious.... but they are cheaply made. The Superlux especially has very thin/resonant plastic...it feels like if I can pay a little attention to the details of controlling resonances in the housing for the best sound possible, these 'budget' headphones will reproduce my music beautifully....which is the WHOLE point.
I have had good cars that can be made great by simply addressing the corners that the manufacturer cut. (it's AMAZING the difference an aluminum radiator makes over a plastic one when you are trying to autocross in the Texas heat!) and the more I look at my headphones and try to understand why one sounds better than another, it feels like too much reflection or glare coming from the housing is part of the problem. It looks like like y'all have put A LOT of thought into this (thanks guys! loooooong read lol.) but I didn't see an answer to my question...does having the surface of the sorb facing the soundwaves make a big difference, or is it more about finding the best spot on the surface of the housing?

I wouldn't say that the surface does no absorbtion but I doubt it is significant. The problem is, I believe, sometimes called impedance mismatch. Airborne sounds striking the surface of sorbothane are going to mostly bounce off the surface and not get damped. You can of course dampen airborne vibrations with various foams and fibers but that is not the same problem we are dealing with using sorbothane.

As regards location, I would have thought, all things being equal, you would get best results, applying materials like sorb close to the driver. That said, Sennhesier puts it's damping on the headband of the HD800 and the new HD820, and I suspect also in their new $50K electrostatic.

I recommend 1/4 self stick 70 duro sorb, cut into small squares, no dimension exceeding 1". Applying 2-4 layers of electrical tape over the pieces of sorb will markedly improve performance, giving what is called "constrained damping." You can get sheets about 4X4 or 6x6 in on Ebay for $10.00 or less. I would recommend 1/2" 70 duro sorb, but I have not found any with self-stick. Finding a good glue a problem. Superglue will hold, but seems to create a barrier to the vibrations getting to the sorb. I have used a very expensive Lord glue recommended by Sorbothane, but it is costly ($70.00 minimum order) and messy.
 
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Jan 24, 2018 at 11:36 AM Post #910 of 952
it really depends on the main target. doing anything inside the headphone's cup adds probable(even if small) changes in the acoustic chamber.
so if the main idea is to just limit vibrations from propagating inside the headphone cup and headband, I would rather pick areas less likely to change the signature(although I imagine heavy headphones and/or strong clamping would do the best job in this case. too bad I can't stand either).
now fooling around inside the cup can be fun too and could kill 2 birds with one stone, but IMO it's for a more elaborate purpose and I would highly recommend having some means to measure the results.
 
Feb 26, 2018 at 4:54 PM Post #911 of 952
Feb 26, 2018 at 5:14 PM Post #912 of 952
Feb 26, 2018 at 7:14 PM Post #913 of 952
that's 36 square inches of sorb...It's my understanding that one inch squares are the preferred size....so, lets say there are thirty usable pieces here (adjusting for shrinkage in all that cutting) how many headphones could I reasonably treat with this?
 
Feb 26, 2018 at 7:30 PM Post #914 of 952
It is relative to the number of pieces around 1 inches you need for a specific headphones.... For my he 400 I used certainly half of the 36 square inches or a little more, for my akg k 340 little less than that...And the pieces I used where always smaller than this one inch squares except some pieces for the headband....
 
Mar 4, 2018 at 1:36 AM Post #915 of 952
I was using 1 centimeter squares as a baseline generally.
=1 Inch seems like a lot/excessively large considering I often could not use many depending on headphone in question.
You do not want to go overboard on this stuff, for me it's incremental tweaking to a critical point, and over that line it can ruin the headphone's characteristic sound ( often overboard they possibly can all start to sound the same :frowning2: )
Speakers would obviously be a different case
 
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