Damping Mechanical Energy Distortion of STAX and other phones with SORBOTHANE and other materials.
Mar 17, 2016 at 4:00 PM Post #466 of 952
  That's impressive. Maybe we need to look into this material for headphones. I was aware that there are other materials out there but haven't seen any claims yet for audio usage other than dynamat which is sold for soundproofing but gets some use as a damping material in headphones too. It could be that very soft (low duro) sorbothane could do what is shown in the video too.  Sorb is used in some helmets but I  don't know if the NFL is seriously working on the most effective shock absorbing/damping material. 


The price of Alpha Gel makes sorbo look pedestrian by comparison. 1.5cm cubes are about 2.50 euro each. Another alternative are moon gel pads. These are the silicone compound that musicians use to damp drum kits. For those there is an economical alternative. Those window stickers you buy for your kids are actually the same compound. It's good stuff but not as strong as sorb in damping vibration. It is a fine tuning material.
 
Mar 17, 2016 at 8:06 PM Post #467 of 952
The price of Alpha Gel makes sorbo look pedestrian by comparison. 1.5cm cubes are about 2.50 euro each. Another alternative are moon gel pads. These are the silicone compound that musicians use to damp drum kits. For those there is an economical alternative. Those window stickers you buy for your kids are actually the same compound. It's good stuff but not as strong as sorb in damping vibration. It is a fine tuning material.

 


Have you compare alpha gel to sorb. for damping audio gear?
 
Mar 17, 2016 at 8:28 PM Post #468 of 952
 
 
The price of Alpha Gel makes sorbo look pedestrian by comparison. 1.5cm cubes are about 2.50 euro each. Another alternative are moon gel pads. These are the silicone compound that musicians use to damp drum kits. For those there is an economical alternative. Those window stickers you buy for your kids are actually the same compound. It's good stuff but not as strong as sorb in damping vibration. It is a fine tuning material.

 


Have you compare alpha gel to sorb. for damping audio gear?


No I have not. Cannot find a decent source and as mentioned it is pricey stuff. What I do glean from their info is it works best between two solids. It is not elastic and does not return to shape naturally so just using it as a single sided damping material may well lead to a constant change in the sound sig. They describe it as more of a liquid by nature than solid material so it needs to be well supported.
 
Mar 17, 2016 at 8:32 PM Post #469 of 952
No I have not. Cannot find a decent source and as mentioned it is pricey stuff. What I do glean from their info is it works best between two solids. It is not elastic and does not return to shape naturally so just using it as a single sided damping material may well lead to a constant change in the sound sig. They describe it as more of a liquid by nature than solid material so it needs to be well supported.

 



I have observed that sorbothane make better damping if place under stress 50 to 75 % for example between two granite plate compressing it under my amplifier..... I had put 2 bricks on the granite plate on the dac with sorb. under it because the load was too light ... i had bricks on the power strip and energizer to compress it also ... The results are very audible...The great discovery for me what it is necessary to apply damping method with sorbothane to ALL THE GEAR....not only headphone....
 
Mar 18, 2016 at 4:03 AM Post #470 of 952
The weight of the amp itself should compress the sorb 50% or more unless you have chosen hard option of 70. Why would you need still more weight?
 
Sorb hemis are designed for optimum compression as they are stuck wide cut diameter up. 
 
I am not trying to argue with you, but to get more relevant logic/information.
 
Mar 18, 2016 at 8:34 AM Post #471 of 952
You are right, this 50 % rule is good start, if the amplifier is compressed adequately it is not necessary to put some supplementary load....My amp compressed adequately the sorb. I had put it between 2 granite plate under my amplifier because the result are better : the amplifier is more stable on his feet, and the load is adequately homogeneously compressed, i had try 30 duro but it was not sufficient and it was too much compressed, and the inside load of the parts of my amplifier is not equally distributed, the transformer is very heavy on one side, hence i put 70 duro little pad on one side and 50 duro pieces on the others side under the amp between this 2 granite plate... Same with 50 duro piece with my sub woofer

For the energizer, it is too light load, the result without some compression with some bricks under it was more satisfying, the gear floated under the 30 duro piece hence with some load the results was better and very audible for me....Same reasonning with my very light power strip..... Idem for the very light bushmaster dac.... The compression of the sorbothane give the better result for me....
 
Mar 18, 2016 at 1:28 PM Post #472 of 952
No I have not. Cannot find a decent source and as mentioned it is pricey stuff. What I do glean from their info is it works best between two solids. It is not elastic and does not return to shape naturally so just using it as a single sided damping material may well lead to a constant change in the sound sig. They describe it as more of a liquid by nature than solid material so it needs to be well supported.

 



I have observed that sorbothane make better damping if place under stress 50 to 75 % for example between two granite plate compressing it under my amplifier..... I had put 2 bricks on the granite plate on the dac with sorb. under it because the load was too light ... i had bricks on the power strip and energizer to compress it also ... The results are very audible...The great discovery for me what it is necessary to apply damping method with sorbothane to ALL THE GEAR....not only headphone....


I can't quite tell what was done here. It seems that several things could be happening. If the bricks are on top of the equipment this will not only compress the sorbothane but will also add mass to the item of equipment. This is a trick which has been reported for years to improve sound quality, probably for much the same reason as sorbothane works, the brick dissipates mechanical energy through its mass.

You could test the crompression hypothesis by separately compressing the sandwich of plates and sorbothane with someting like C-clamps.

I have also been trying sorb on power strips and am pretty sure that I am hearing an effect here. I can't imagine what is going on here other than that the 60 cycle power is causing some mechanical hum which causes microphonics in the cables. This gets damped by the sorb. I would not be surprised if no-one believes me. I find it hard to believe myself.
 
Mar 18, 2016 at 7:41 PM Post #473 of 952
I can't quite tell what was done here. It seems that several things could be happening. If the bricks are on top of the equipment this will not only compress the sorbothane but will also add mass to the item of equipment. This is a trick which has been reported for years to improve sound quality, probably for much the same reason as sorbothane works, the brick dissipates mechanical energy through its mass.



You could test the crompression hypothesis by separately compressing the sandwich of plates and sorbothane with someting like C-clamps.



I have also been trying sorb on power strips and am pretty sure that I am hearing an effect here. I can't imagine what is going on here other than that the 60 cycle power is causing some mechanical hum which causes microphonics in the cables. This gets damped by the sorb. I would not be surprised if no-one believes me. I find it hard to believe myself.

 



I think that a better explanation is that the sorbothane must be compressed optimally for not only isolating but damping effectively the vibration, certainly the brick's mass isolate from the vibration and absorb it but not like the sorb and the change in the sound was for the better all across the frequencies if the sorb. is optimally applied, hence I dont think that putting brick on gear "per se" damp effectively for the better...But it is only my opinion,neither do i really understand the phenomenon...For me i think that the sorb act like a filter that act on some resulting resonance effect...properly sorbothanized but only properly applied, the filtering effect go in the same direction on all frequencies :filtering some noise and reveal a better tonal and a better rendering of the musical timbre ... But it is only my uninformed explanation... thanks God and your mother to your existence edstrelow , i dont have acute upgraditis now anymore....

Just an exemple of one of my simple experiment i add only one brick on top of my subwoofer, and the effect was no short of extraordinary : middle frequencies and bass more define and better imaging, and all that with only one brick on top of my sub ... it is clear for me that before that the sorb under it was not optimally compressed and then the filtering effect of the damping sorb was less than optimal, it was good but not optimally good....The load of one brick compress it more and WOW ! ...

In the beginning i naively think that putting sorb. under gear will made the difference...it is not so simple but the basic rule was simple : choosing the right duro is the first part of the job, the second part is compressing it optimally because compressed sorb. react more sensibely to the resonance vibration and absorb and dissipate it better.......
 
Mar 19, 2016 at 6:49 PM Post #474 of 952

 

 
Here I have made a direct comparison of the benefit of using smaller vs larger  pieces of sorbothane on a Stax SRXIII pro. I keep the amount of sorbothane the same in each set-ip.  Many of us have been using smaller vs large pieces for some time, but I wanted to do a reasonably precise and direct comparison with a set-up where it is easy to go from one set-up to the other.  The original suggestion about using smaller pieces I believe came from some advertising material from a sorbothane seller and many of us seem to think that its is a good idea.
 
DETACHABLE COVERS
 
The SRXIII phones have a detachable metal front cover which can be quickly removed by popping off the headband, unscrewing the two screws on the side and pulling off the cover.  Since I had a extra pair of covers from an old broken low bias set, I was able to compare the effect of cutting a given size of sorbothane into smaller pieces, simply by changing the covers.  This process takes less than 2 minutes.
 
SIZES OF SORBOTHANE AND LOCATION
 
I cut 8 strips of  1/10 inch thick, 40 duro sorb from a 3 inch sheet.  each strip is about 3/8 inch wide, all that could be placed on the cover.
On one set of covers I put two 3 inch strips on the top and bottom of each cover.  On the other set of covers I cut the 3 inch strips into 4 equal sized pieces. Thus each earcup had either 2  three inch strips or 8 smaller pieces which would total 6 inches in length.
 
 
LISTENING RESULTS
 
I have been listening to these for  3 days now, going back and forth between the two sets of covers, and the results are quite striking.
The sound using the smaller pieces of sorb is much better on these phones. A lot of scratchy high frequency sound is gone. The bass is firmer, the individual instruments stand out more clearly and there are better dynamics.
 
There is no other sorbothane on the earcups other than what I describe although I did leave 4 small pieces on the inside of a section of the headband as shown in the second picture.  This headband damping is surprisingly effective on its own and I owe richard51 credit for pointing this out on the SR5, which has a similar headband to the SRXIII. I would otherwise not have expected any benefits of placing sorbothane  here on this type of headband but I was wrong. I had originally started using sorbothane on the SR007A headband but its construction is very different from the SRXIII and SR5 because the SR007 earcups screw directly into its earcups. The other phones are far less directly fastened to their earcups.    Of course as best I can tell Sennheiser puts all its damping materials in the headband of the HD800  so maybe they know something about this. I suspect they would do the same with their new super electrostatic.
 
To put this in perspective, the SRXIII pro,  as it is tricked out here with the smaller pieces, is a very listenable phone and I spent quite  a long time just enjoying it.  Using the covers with the longer strips gave some benefit, compared to no sorbothane on the covers, but did not really give you anything you would want to spend a lot of time with.
 
I have reported on the SRXIII in the early pages of this thread and I am not saying that the current set-up is my last word on these phones. Once I have done  a few more comparisons I will probably review the lessons learned and try to come up with the best damping I can find for these phones. 
 
Mar 20, 2016 at 11:49 AM Post #475 of 952
i cannot wait in the few months to come to buy a srx MKIII  and try that for myself
smile.gif
.... thanks Ed
 
P.S. a question : some people has described the srx more studio. cans , more resolving headphone than the musical SR-5, Is the sorbothane mod. elevated them on a more musical level ? you seems to enjoy them a lot...
 
Mar 20, 2016 at 12:24 PM Post #476 of 952

 
I have said many times here that for optimal results the sorbothane must be compressed when possible, I put this morning another load on top of my subwoofer, how did i knew that it is necessary? I only try that without hoping much because the last time  i add a load on top of it the result  was very good already, but now with 2 bricks not only one,  it seems the sorbothane was finally  compressed optimally, because The mid frequencies of my speakers liberate themself, the bass was no more interfering with them and all the imaging was incredible... I know now why those who owns the Monsoon MM 2000 so to speak, kill themself, if they cannot repair or replace it...
atsmile.gif

 
I am very happy....thanks  for this thread, i will no more name his initiator because it will be too much praise for his humility , but i am very happy, more than ever, music give me like all of you the joy i crave in for......
L3000.gif

 
P.S. Before reading this thread some 6 months ago , i was unhappy with all my buying... Something was always wrong or not completely satisfying, and all people's  post i read about  think of this  new headphone or of that one, or of this new amplifier or of that other one, and they say, mids are this way better , the bass, this way better , the highs this way better , and reading them with my unsatisfaction  i was hoping for the better and  try buying some upgrade with no complete satisfaction in the end... In the end  i was dreaming to buy a new high end amp more than one thousand dollars, and for sure some new dac in the same range, and also for sure some newer headphone,between one thousands  and 4 thousands dollars for the headphone only for sure ...OUFF
 
But when i start reading Edstrelow i decide to try with his  sorb. mod. and all things suddenly fall into place gradually, so much better than i think..  after experimenting with my  love-and-hate he-400 hifiman i decided why not to try an old Stax model, like  old srx MKIII of edstrelow,  i decide to buy the SR-5 who was the better in the world  in 1975 with one of  the better amplifier in the world in 1975,(Sansui AU-7700) and i bought all  that for less  than 400 + refurbishing of the amp included ...Guess what,  after many experimentation with the sorbothane and the right application of it on the 6 element part composing my complete system , it will be very difficult for me now after the SR-5  to spend more because when you already have a natural and musical rendering of the timbre and tonality  and  clear depth imaging it is end of the game, some more  superior gain would be certainly possible but the  result will be minimalistic for the  higher, very higher price you must pay for, this is the famous law of diminishing return...I had  said all that for you all if, like me, you dont have plenty of money to spend and if you dream  desesperately of audiophile gear.... yes it is possible at low cost...
 
Dont spend your money too swiftly for newer gear, wait,  read, inform youself and you will experience that it is possible to be happy with very few dollars  system adequately implemented...  Me, i am no more jealous of 20,000 thousands dollars system i see here and there, yes they are better to begin with, but compare to what i have now, i know for sure they will be put to shame by my gear, rightly sorbothanized, that cost me  a ridiculous final price,( i will call my gear :high level audio for the poor ) after all you cannot have better than an already natural, musical, rendering of the instrument and vocal timbre, you may only have perhaps better resolving or larger soundstaging headphone, but often at the price of less musicality, Stax try that after the SR-5, they call them lambdas and other names  ....
 
Now you understand why  i praise so much this thread's existence... thanks to you all for your patience with my bad english writings...
 
Mar 21, 2016 at 3:26 AM Post #477 of 952
i cannot wait in the few months to come to buy a srx MKIII  and try that for myself :smile: .... thanks Ed

P.S. a question : some people has described the srx more studio. cans , more resolving headphone than the musical SR-5, Is the sorbothane mod. elevated them on a more musical level ? you seems to enjoy them a lot...


These were my first Stax phones although I sold them to friend when I left New Zealand for the US many years ago. Since then I have bought 2 more low bias models and 1 high bias. Both sound similar but the high bias has somewhat more power and dynamics.

These phones were reported to have a very smooth frequency response and were I believe at one time popular for use as monitors. Their mian weakness is a lack of deep bass.

However sorbothane damping really brings their performance up, reduces harshness improves dynamics, tonal accuracy etc. All the things you would now be aware of from playing with sorbothane yourself.

Just today I tried my low bias model with sorbothane only on the headband as you reported for the SR5 and that alone gives the phone a significant improvement. (The picture shows the damping on the headband and some sorb on the earcups of the high bias phones although I did not do this on the low bias phones)
 
Mar 25, 2016 at 12:57 PM Post #478 of 952



 Experimenting with the square logo plate,at the basis of the headband with sorb., i  have definitevely observed a relation between the thickness and duro and some blurred medium frequencies emphasis ... I had tried finally with success(better imaging, hence better highs and bass without blurring mids emphasis) to put in place  the sorbothane with some  2 cheap paper clip on each cups  : 2 square pieces of sorb. duro 50 1/4 inches optimally compressed in place with a bigger paper clip in the first half of the  logo-space, and 1 thinner rectangular sorbothane band 1/8 inches duro 40 in the other half with a smaller paper clip, i must put one plastic  strip band,between the clip and the sorb. on the headband plate for better grip and homogeneous pressure under it,only with the one piece 1/8 rectangular piece of sorb, a plastic strip with the 2 pieces 1/4 duro were not necessary for the stability of the grip  ...
 
i think that the  complementary difference in duro and thickness of this 3 pieces of sorb. compressed on each side of the headband made a difference... Like  together making a filtering effect, and giving more clarity and keeping the body without compressing or  blurring  all in the mids,  as always when there is for example to much, or too thick sorb pieces .... I will wait for other with SR-5 to experiment with this idea...
 
Now all is stable and the sound is to my ears very good with an interesting depth imaging....I think that the resonance filtering effect of the sorbothane added on the headband  between each cup already sorbothanized under the earpads is evident and i love my SR-5 ... Good music to all of you
L3000.gif
 
 
Mar 26, 2016 at 6:24 PM Post #479 of 952
 
 Experimenting with the square logo plate,at the basis of the headband with sorb., i  have definitevely observed a relation between the thickness and duro and some blurred medium frequencies emphasis ... I had tried finally with success(better imaging, hence better highs and bass without blurring mids emphasis) to put in place  the sorbothane with some  2 cheap paper clip on each cups  : 2 square pieces of sorb. duro 50 1/4 inches optimally compressed in place with a bigger paper clip in the first half of the  logo-space, and 1 thinner rectangular sorbothane band 1/8 inches duro 40 in the other half with a smaller paper clip, i must put one plastic  strip band,between the clip and the sorb. on the headband plate for better grip and homogeneous pressure under it,only with the one piece 1/8 rectangular piece of sorb, a plastic strip with the 2 pieces 1/4 duro were not necessary for the stability of the grip  ...
 
i think that the  complementary difference in duro and thickness of this 3 pieces of sorb. compressed on each side of the headband made a difference... Like  together making a filtering effect, and giving more clarity and keeping the body without compressing or  blurring  all in the mids,  as always when there is for example to much, or too thick sorb pieces .... I will wait for other with SR-5 to experiment with this idea...
 
Now all is stable and the sound is to my ears very good with an interesting depth imaging....I think that the resonance filtering effect of the sorbothane added on the headband  between each cup already sorbothanized under the earpads is evident and i love my SR-5 ... Good music to all of you
L3000.gif
 


Yes it is amazing that just damping the headband ​of the SR5 should make such an audible difference.  While I knew that the band of the SR007 needed damping, I discounted the other designs because I felt that they were too loosely linked to the earcups to pass much vibration.   Evidently I was wrong on that issue, since  not only is headband damping an issue with the SR007 and the SR5 but also the SRXIII (which has a very similar headband to the SR5) and most importantly the Lambda. I say the latter because the Lambda is still a current design and, based on the number of Lambda models, it has to be the most common Stax phone out there.  Also as best I can tell, it also employs basically the same headband system for all its models.
 
Exactly what compression of sorbothane does is an issue remaining to be better understood.  It seems to me that it improves the contact of the sorb with the surface of what it is in contact with, thus probably allowing more vibrational energy to leave the surface to be damped by the sorb.  However it also puts mechanical force on the sorb, possibly changing its damping characteristics.  Of course both factors could be at work.  It would be nice to be able to vary them separately, but I am not sure how that could be done.
 
As regards ways of clamping and compressing sorbothane, here are some of the things I have tried.
 
First I made my own clamp from two pieces of stiff plastic and held together with a nut and bolt. The big advantage of the bolt and nut is that you can tighten and loosen the clamp, thus adjusting the pressure. You can see this on my SR007:
 

 

 
 
However, I have also tried two commercially available clamps:
:
 
I have not yet found an application for the black c-clamp, but I have used the smaller one on my SR007 but found the plastic clamp seen above to be more stable.
 

 
Mar 27, 2016 at 11:16 AM Post #480 of 952
interesting! i will wait for your impression with clamping sorb. thanks Ed
smile.gif

 

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