[edstrelow]

 
i will open it ( i had already the sorb. for that )....But for now enjoying the Sr-5 is so extraordinary for me that my motivation to made the move is low.... Like you said probably this organic musical  coherence  effect of the sound  is linked somewhat to the circular membrane and the design of the chamber cup versus  rectangular cheap plastic atrocius square

....I am sure now that to made my system really better than what i have now and not a sidegrade move, a real upgrade move will cost me thousands of dollars... I plan to try with the money of my  "old age" the microzotl amp + a linear power supply  with an energizer for my Stax SR-5.... Only this will cost me near 2 thousand.... And for upgrading the dac one thousand more....I will made that around the Stax SR-5... I am afraid to buy an headphone now without hearing it before buying, because of this inherent musical quality of the SR-5... I have observed that without sorb. the SR-5 was musical already....I know that sorb dont make a non organically musical headphone  an organically musical one... Hence i am stuck with the SR-5 for a good time to come

 

Here is an easy sorb mod to try.  Following your comment about putting sorb on the head band of the SR5, I have tried doing something similar on a Lambda 404 and my Sigma/404.  (see pix)  I think I am hearing something good, but each of my phones already has sorb mounted near the drivers so it is a bit unclear.   If you haven't yet modded your Lambda yet, possibly you can put a few pieces of self-stick on the headband and let us know if  you think it does anything.  I chose the underside for cosmetic reasons.
 

 

 

[zolkis]

Did anyone make measurements on the effect of various thickness/duro etc or Sorbothane in any headphone applications?
 
I know that tuning "by ear" also works if you have a good test bed and methodology, but using measurements speeds up considerably the process of converging to optimum, and the understanding how damping works in a certain application. I have recently set up (thanks to Sorrodje) a cheap, but calibrated MiniDSP UMIK1 USB microphone with the free RoomEQWizard program and a DIY coupler, and started measuring what I was doing. I will make a post about my rig later.
 
I am testing again all my optimizations on the TH900 and 007 through measurements + listening tests now, it's so much more efficient. I noticed there is a huge measurable difference on the effects of earpads and other damping (in the order of 6-18 dB depending on frequency). Even small differences (2-3 dB) make quite a big subjective difference during listening tests, but now I have a better correlation tool for optimizing parts vs optimizing the whole.
 
I expect my Sorbothane shipments arrive in the weekend or early next week and will post some measurements. 

 

[richard51]

 
Here is an easy sorb mod to try.  Following your comment about putting sorb on the head band of the SR5, I have tried doing something similar on a Lambda 404 and my Sigma/404.  (see pix)  I think I am hearing something good, but each of my phones already has sorb mounted near the drivers so it is a bit unclear.   If you haven't yet modded your Lambda yet, possibly you can put a few pieces of self-stick on the headband and let us know if  you think it does anything.  I chose the underside for cosmetic reasons.
 

 

very good idea i will try and report it here ! trhanks Ed

 

[richard51]

  Did anyone make measurements on the effect of various thickness/duro etc or Sorbothane in any headphone applications?
 
I know that tuning "by ear" also works if you have a good test bed and methodology, but using measurements speeds up considerably the process of converging to optimum, and the understanding how damping works in a certain application. I have recently set up (thanks to Sorrodje) a cheap, but calibrated MiniDSP UMIK1 USB microphone with the free RoomEQWizard program and a DIY coupler, and started measuring what I was doing. I will make a post about my rig later.
 
I am testing again all my optimizations on the TH900 and 007 through measurements + listening tests now, it's so much more efficient. I noticed there is a huge measurable difference on the effects of earpads and other damping (in the order of 6-18 dB depending on frequency). Even small differences (2-3 dB) make quite a big subjective difference during listening tests, but now I have a better correlation tool for optimizing parts vs optimizing the whole.
 
I expect my Sorbothane shipments arrive in the weekend or early next week and will post some measurements. 

 exciting! i cannot wait for your results... thanks very much ...

 

 

[edstrelow]

I don't know what is going on but I look forward to any measurements here. My guess is that sorbothane damping reduces distortion and I would not necessarily expect it to change the frequency response of a headphone. However that is merely a guess and I may be guessing wrong.

I have personally spoken with technical reps at Sorbothane a few times and they had done virtually no measurements of the sonic effects of sorbothane.

What I would personally like to see measured is the mechanical vibrations in various parts of the earcups, with a sensor that attaches to the physical structure rather than a microphone that is measuring sound in the air.

 

[zolkis]

My guess is that sorbothane damping reduces distortion and I would not necessarily expect it to change the frequency response of a headphone.

(...)
I have personally spoken with technical reps at Sorbothane a few times and they had done virtually no measurements of the sonic effects of sorbothane.

 
I think it will change the frequency plot because every material in the way of audio waves does that. However, distortions and impulse response change are valid enough measurement data.
 

What I would personally like to see measured is the mechanical vibrations in various parts of the earcups, with a sensor that attaches to the physical structure rather than a microphone that is measuring sound in the air.

 
Since these vibrations cause harmonic content, they will show up in the distortion and impulse response measurements. Sometimes these give a better idea about how a change sounds than the frequency plot, but in my experience usually that changes also.

 

[edstrelow]

   
I think it will change the frequency plot because every material in the way of audio waves does that. However, distortions and impulse response change are valid enough measurement data.
 
 
Since these vibrations cause harmonic content, they will show up in the distortion and impulse response measurements. Sometimes these give a better idea about how a change sounds than the frequency plot, but in my experience usually that changes also.

Many years ago I worked in a lab with a state of the art Bruel and Kjaer frequency response system which cost as much to buy  as a new house. It used 30 sets of filters such that when it measured say 500 Hz it eliminated everything else from consideration. It was good for what it did, but would not register any distortion product away from the target frequencies. That's what I am thinking could be missed.  
 
I should add that Grado claims that their new polycarbonate material, used in the construction of their e series headphones, affects transient response.  So impulse or square wave measurement could be where to look. 

 

[zolkis]

Hmm, maybe I fell into a measurements fallacy. When in doubt, trust your ears - and training them never harms either
Anyway, let's see if something can be measured that sticks out of statistical measurement errors.

 

[richard51]

With only my ears in 5 seconds, the change was dramatically better, spectacular change , clarity without any distortion...... The imaging of these monsoon speakers gain so much that i like that speakers on par with my beloved Stax SR-5 after applying the sorbothane (5 pieces duro 30) ....
 
Conclusion : sorbothane is not for headphone only....
 
 
 
 

 
And If you have an  heavy amplifier put 2 granite slabs with in between some sorb. with the adequate duro for the weigh, and thank me not but the initiator of this thread 

 
By the way when applying sorb sometimes too much is worse, i have originally put 3 more pieces on the monsoon speakers  that i had put off because the sound was too compressed, experiment and try....
 

 

[edstrelow]

I find that the sound generally changes after a few hours/days as the glue or self/stick bonds so it can take a bit longer determine the best sorb arrangement. Often I find that the sound is slightly bass heavy when the sorb is first applied andcthis eases off after a few hours. So these days I usually let the system sit overnight before I decide if its properly damped.

 

[edstrelow]

Hmm, maybe I fell into a measurements fallacy. When in doubt, trust your ears - and training them never harms either
Anyway, let's see if something can be measured that sticks out of statistical measurement errors.

Certainly if it doesn't sound good to.me I don't care what the measurements show. Still there's a lot of basic science needed to try to understand what is happening here, so some measuremens may help.

 

[richard51]

I find that the sound generally changes after a few hours/days as the glue or self/stick bonds so it can take a bit longer determine the best sorb arrangement. Often I find that the sound is slightly bass heavy when the sorb is first applied andcthis eases off after a few hours. So these days I usually let the system sit overnight before I decide if its properly damped.

i have verified that effectively, but sometimes the result were so good, the change so effective, than it is immediately felt, but the time goes on and the gluing process add some new flavor for the better.... The change in my  speakers were not so good the first day, because i had put too much sorb. but after one day i decide to reverse it slightly by removing 3 pieces of sorb. and cutting the remaining one in 2... the change was so better than it was immediarely felt in a less compressed sound, with time and gluing process i dont doubt that  will be better...that was the same in my He-400...

 

[Hutnicks]

Certainly if it doesn't sound good to.me I don't care what the measurements show. Still there's a lot of basic science needed to try to understand what is happening here, so some measuremens may help.

Not completely convinced that the measurement junkies have it right at the best of times.
 
Using materials to damp out mechanical vibrations would tell me that the logical way to proceed would be to measure the phone to see where it is vibrating and at what frequencies. That means the outside, the headband, etc. Simply stuffing materials in and on a phone and measuring the resultant change in sound sig  strikes me more and more as a crude shotgun type approach.
 
Tyll has an article about the HD800S which pretty much illustrates the differences between the modder who claims to use the "scientific method" and the manu who actually understands it and employs it.

 

[edstrelow]

Not completely convinced that the measurement junkies have it right at the best of times.

Using materials to damp out mechanical vibrations would tell me that the logical way to proceed would be to measure the phone to see where it is vibrating and at what frequencies. That means the outside, the headband, etc. Simply stuffing materials in and on a phone and measuring the resultant change in sound sig  strikes me more and more as a crude shotgun type approach.

Tyll has an article about the HD800S which pretty much illustrates the differences between the modder who claims to use the "scientific method" and the manu who actually understands it and employs it.

I totally agree that measurements of the vibrations of the structure of the headphones are probably the key to understanding what is happening here. Unfortunately few if any of us have the equipment to do these measurements.

My theory is that the entire sound signature of what is put out through the driver goes into the earcup as well, as is predicted by Newtonian physics. To the extent that these vibrations are not damped by the structures of the earcups (and damping by sorbothane means coverting the energy to heat, again Newton since energy is not created or destroyed) they cause audible distortion. I don't know if this distortion is because the vibrations of the eacups get transmitted through the air to the ears or by feed back through the earcup structures to the drivers. Both explanations might even apply so this might not be an either/or situation.

 

[Hutnicks]

I totally agree that measurements of the vibrations of the structure of the headphones are probably the key to understanding what is happening here. Unfortunately few if any of us have the equipment to do these measurements.

My theory is that the entire sound signature of what is put out through the driver goes into the earcup as well, as is predicted by Newtonian physics. To the extent that these vibrations are not damped by the structures of the earcups (and damping by sorbothane means coverting the energy to heat, again Newton since energy is not created or destroyed) they cause audible distortion. I don't know if this distortion is because the vibrations of the eacups get transmitted through the air to the ears or by feed back through the earcup structures to the drivers. Both explanations might even apply so this might not be an either/or situation.

The issue of aerodynamics comes into play as well. Baffle grills, coverings, reflected sounds all play a part in the sig.
 
I think you can probably use a small mic and put it in contact with cups, headband, and other parts to get a fair determination of what the largest culprits would be.