[edstrelow]

Re: sorbothane under pressure. I have been on this problem for a few years and there is even one earlier thread just dealing with the Stax SR007. I have talked a couple of times with technical reps as Sorbothane who gave me some pointers but had little to specifically discuss about speakers and headphones. Often it is used in industrial applications, as footers for equipment but it has to be carefully tailored to the weight of the object and the frequencies needed to be damped. Vibration damping is a big deal to mechanical engineers and I have discussed what I have been doing with a half a dozen, and they they all seemed to understand and agree with the approach. I do recall talking to one of the Schitt designers who acknowledged the use of sorb to dampen circuits in some of their equipment. To my mind this problem is one of the last frontiers of audio.

My first efforts used clamps on the sorb but over time I found I used little pressure to get the best sound. Then I started just sticking the sorb on using the self-stick or other glues and it seemed that I was still getting good results and I stopped playing with clamps. Still later I used electrical tape to hold some in place on headbands, by wrapping the sorb to the band. I liked that even more, and finally realized that simply covering the back with tape gave as good result as wrapping. I got the term "constrained" damping from Mitchell who did the measurements of mechanical crosstalk on headphones. That does not imply pressure, just a wall of sorts on the back of the material.

There's a lot of basic physical measurement needed here to understand the phenomenon and to determine the best methods of damping. I would like to see measurements of the amount of vibration in earcups and speaker boxes and then a concerted effort to dampen it to non-existence. Then I want to hear what non-vibrating speakers and phones sound like.

 

[edstrelow]

I haven't added anything here for some time. Basically I have pretty much solved the damping issues problem with my Stax phones and have been working more with speakers. These sobothane mods remain the best and cheapest improvement in sound you are going to find and I expect in the next few years to see major adoption of this and possibly other damping techniques to speakers and headphones as well as some items of equipment which have vibrational issues, such as CD/DVD players and amplifiers.

 

[ericj]

I came across this reading about HE400S mods, since i finally bought a modern ortho.

I just wanted to say, as a senior member of Team Cheap Bastards, that I'm disappointed to be the first person to mention Peel-n-Seal, Dynamat's affordable cousin.

Got most of a roll of it here. Used a few feet of it to deaden ringing in plastic PA speaker horns. Worked a treat.

 

[edstrelow]

Peel-n-Seal

" I came across this reading about HE400S mods, since i finally bought a modern ortho.

I just wanted to say, as a senior member of Team Cheap Bastards, that I'm disappointed to be the first person to mention Peel-n-Seal, Dynamat's affordable cousin.

Got most of a roll of it here. Used a few feet of it to deaden ringing in plastic PA speaker horns. Worked a treat."

I am sure that many things, blue tack, peel and seal etc. can be stuck onto speakers and headphones and just about anything that sticks properly and adds mass will provide some damping. However these are designed for some other purpose eg. fixing roofs. Sorbothane has some scientific background as a means of specifically dampening vibrations by changing the mechanical energy into heat in accordance with the conservation of energy. I see no such claim for these other materials. In my experiments, reported here I have compared types and sizes of sorbothane and find the best results are fairly small, thick, dense (70 duro) pieces, properly glued and backed with, in my case, 4 layers of electrical tape to achieve " constrained damping." I did one direct comparison with comparably sized blue tack pieces and found it had only a slight effect compared to sorbothane. But there has been so little good discussion and understanding of these issues I nevertheless like to see other solutions suggested.

I am sure that Sennheiser, which has been doing damping on its better phones for years, has some good data but it is probably considered "proprietary" and will not be released to the public.

 

[BoyNamedSue]

Reviving an old thread...TBH, I'm a bit skeptical but the cost is so low, why not?

I have been focusing on modding my Jade 2's. They are the fastest and most transparent headphone I've had in my system, vocal/acoustic music is very lifelike, but there is a lack of sub bass and bass impact that makes them genre specific. I'd say the overall sound signature is thin and bright. I suspect the housing may be the issue as it is very light and plasticky. Thus, I am wondering if applying sorbothane would help increase the bass. I am thinking of adding them to the sides of the ear cups as well as the headband, spaced out in small blocks. It sounds like 70 duro is recommended, and I am leaning towards 1/8" for aesthetic reasons over the 1/4". I don't mind losing some transparency and even some sound stage if bass can be improved.

Internally, I've removed the plastic filter which made the sound more natural, and had to remove the dust cover, leaving the mesh stators in a naked state. I notice that there is some small flat surfaces near the edges of the mesh stators. This is likely an ignorant question, as I am not a technical guy, but would it be safe and potentially improve SQ to apply a bit of sorbothane directly on top the flat surfaces of the mesh stators?

 

[Maxx134]

Hey guys, I see thread activated in my notifications I forgot I was following this .

Anyways,
I feel I should mention the traditional ways to use materials most effectively.

So Sorbothane's energy absorbent qualities, or design of performance is done "under tension", thru two choices or conditions, which are both compression, and expansion.

In no other way was sorbothane designed or intended to be used, and so I am not sure to the optimal effectiveness of how it is being used differently applied in this thread.
Yet I will not argue any changes or results hopefully benifiting others.

Also simply using sorbothane as a surface material, to rely on its reflective properties is not optimal.

Personally, I would suggest "dynamat extreme" for vibration absorption of housing, but it is not optimal either because of it being messy.
I especially not want to do anything inside the earcup chamber with anything sticky.


So sorbothane in a compression scenario, would be optimal, (such as inside the HD800, which is only discoverable under the driver).

I did try sorbothane in a stretched position around a driver once, but found it wasn't as effective, and broke with age.

For interior of Stax I would prefer to have something to break the earpad seal, in order to relieve inner cup (ear chamber) air pressure, and give the unit a more meaty bass ability.

Then I would look into damping in rear of the chassis sparingly because I have not experienced the stax(009) to have any issues.

 

[Maxx134]

vocal/acoustic music is very lifelike, but there is a lack of sub bass and bass impact that makes them genre specific

Try doing a pad seal port, like done here...

 

[BoyNamedSue]

@Maxx134, thank you for the response! I'll check out the pad seal mod that you referenced. BTW, I often reference your hd800 and he1000 mod threads to get ideas for my headphones. Very helpful and educational!

Regarding sorbothane, I recently applied it to Jade 2's and lets just say I am a believer now. I was honestly skeptical at the significant improvements noted in this thread, even wondering if this thread was marketing for sorbothane, but I can understand the enthusiasm now.

I applied 1cm pieces (1/8, 70 duro, self-stick) all around the exterior of the Jade 2's (along the ear cup and headband), using several layers of electrical tape to both compress and adhere them to the phones.

The differences are not subtle. The sound is overall more natural, as if I am hearing only the music and none of the cup resonances/coloration. The tonality seems more neutral now, whereas before it was bright and airy. The speed is more regular paced/slower as opposed to previously being fast, as if the sound was slightly on fast forward. The sound stage seems more coherent as well, but still a bit 3-blob depending on the recording. I have to raise the dial higher to get the same volume, but I notice it is less fatiguing at higher volumes with almost zero shoutiness, which was a problem before. The music is just as fluid, detailed, and lively as before. The transparency and separation seems to have gone down a bit but seems more realistic, kind of like Paper Mario cut-outs to 3d Mario where edges are more rounded. Lastly, I am finally getting more bass presence and slam, which makes the sound images more solid, full-bodied, and grounded.

The major downside is that my phones look like Frankenstein now. And handling and wearing them now is a bit clunky to avoid accidentally stripping the pieces off.

I'm not sure why its improving things this way, but I read earlier that thickness damps different frequencies, and that thicker is needed to tame lower frequencies. I used 1/8 compared to 1/4 that Edstrelow recommended, which may mean that the cup resonance from mid-range and treble frequencies are being dampened but not so much the low end. Thus, by raising the volume, I may be getting more bass relative to the other frequencies. I don't know if this logic makes sense but may explain why bass response has improved. In addition, the headphones feel a bit heavier so not sure if it is more of the mass loading making a difference.

On a side note, the improvements seem to confirm my suspicion that the Jade 2's drivers are really good and the culprit is the housing. The headphone assembly seems to be primarily utilitarian versus the design of the HD800's structure/form factor, which seems to be designed for acoustic purposes.

 

[jesh462]

I feel I should mention the traditional ways to use materials most effectively.

So Sorbothane's energy absorbent qualities, or design of performance is done "under tension", thru two choices or conditions, which are both compression, and expansion.

In no other way was sorbothane designed or intended to be used, and so I am not sure to the optimal effectiveness of how it is being used differently applied in this thread.
Yet I will not argue any changes or results hopefully benifiting others.

When I first saw this thread, this was my reaction.
Sorbothane is awesome, and I have used it in audio projects before.
HOWEVER
It is only a de-coupler. It has excellent viscoelastic properties, but that does not make it a constrained layer damper.
Using a purpose-built product is going to have much better results and fit in more spaces.
If you're after the absolute best damping per unit volume, look to Second Skin Audio based out of Illinois. (source: independent testing on DiyMobileAudio.com)
It used to be SoundDeadenerShowdown, but he retired, and his sources are unknown.
Second Skin sells these nice little 3x5 sheets that would be perfect for small projects like headphones and mechanical keyboards.
They also have liquid products that can be applied nearly anywhere and dry to harden.
It is important to note that the best results for CLDs are seen with continuous coverage. In other words, don't cut out 4 little pieces to make a circle. Do your best to cut out the exact shape that you need, and your results will be better.

I would still use Sorbothane inside of a headphone where two pieces are in mechanical contact, and you can fit something in there.
An easy example for the proper use of Sorbothane would be washing machine legs. Sorbothane would decouple the movements of the washer from the floor.
If you can see a place in the headphone where this could happen, Sorbothane will help.
What immediately comes to mind is how the driver is mounted in the enclosure.
Using Sorbothane 100% effectively would require a custom mounting solution in most headphones.

 

[edstrelow]

I have been off this thread for quite a while, mostly because I felt I had figured out how to handle sorbothane damping and had come up with a general understanding of the physics. The latter is basic Newtonian physics, "for every action (force) in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A. In other words, forces result from interactions." Think of it this way, as much energy is going into the case/box of your headphones/speakers as is going into the air and this your ears. This energy sits buzzing around the drivers, some feeding back into the speaker itself thereby messing up the sound. This energy stays around for probably only milliseconds before it transforms to heat, the first law of thermodynamics. Sorbothane even puts this in their ads "Converting energy into heat, Sorbothane® combines the characteristics of shock absorption, vibration isolation, good memory and vibration damping to protect any object." For audio, the problem is that for many/most materials used in headphone/speaker enclosures, this conversion of energy to heat takes too long. Sorb is simply faster.

Someone above raised the issue of whether or not you needed to apply pressure to sorb to for it to work well and the answer is mostly no. I had this misconception too in part because of some of the ads for sorbothane footers emphasized this issue. If you put a very light vibrating objects on a sorbothane footer you will get very little benefit because the vibrations simply won't pass into the footer. Yes, applying pressure from the object to the sorb will improve transmission, however if the footer is glued properly to the sorbothane with a substance that will transmit the vibrational energy you can get very good damping. Some of the commercially available sorb up to 1/4" comes with 3M double sided tape, which seems to do this job well. I also use an industrial glue recommended by Sorbothane (the company) called Lord 7650. It is expensive, messy, hard to find, and deteriorates after exposure to air (I pour it into smaller air tight containers to extend its life) However it works a charm and without it would not have been able to apply the thicker 1/2 " sorb to my speakers.

I have found that even with the sorbothane footers I put under equipment, some like my B&O 8002 turntable, which is quite heavy, the use of 3M or Lord between the footer and the equipment improves the sound quite a bit. In this particular application, the sorb is doing two different jobs: Firstly it is blocking the transmission of sound through the ground to the equipment, i.e. feedback, a big deal with turntables. My other B&O the TX2 was appalling when I first got it and I quickly bought footers for it (initially not made of sorbothane.) However sorb can also absorb the vibrations within the equipment caused by things such as platter rumble which can make its way back to the cartridge. (CD players have related issues with vibrations from the spinning discs upsetting the reading of digital signals.)

 

[richard51]

It has been a long time i did come here...

But i mod all my past headphones with sorbothane duro 70.... With success...

The last one of my headphones, the sextett, and the mighty Akg K340 too with success...

Ed idea was an inspiration for me to study more headphones and even speakers vibrations..

But now life made me an headphone user only.... My headphone of choice is the K340.... An underestimated marvel very hard to figure out and to drive......

 

[bagwell359]

It has been a long time i did come here...

But i mod all my past headphones with sorbothane duro 70.... With success...

The last one of my headphones, the sextett, and the mighty Akg K340 too with success...

Ed idea was an inspiration for me to study more headphones and even speakers vibrations..

But now life made me an headphone user only.... My headphone of choice is the K340.... An underestimated marvel very hard to figure out and to drive......

Ive been using antil damping material on speakers, amps, and more recently headphones since the 1980's. Sorbothane is excellent in the high duro measurements but its expensive and doesn't stick well. For head[hones I use dynamat - cheap, easy to cut, and stays in place. It's not as potent per amount as sorb, but I like it. Use it to control vibrations and to try and get headphones to sound similar to acoustic suspension bass with a Q of .707 - roughly.

I use it on all my cans in order of most to least: HE-500, MD-4XX, HE-5LE, HE-6 SE v1 (all HFM primarily for bass Q) & Senn HD-600 (the body vibrates), and yes the bass is cleaner. Whatever is missing from those treatments and open air bass loss is replaceable by EQ, but no longer under damped bass and amusical vibrations.

 

[richard51]

Ive been using antil damping material on speakers, amps, and more recently headphones since the 1980's. Sorbothane is excellent in the high duro measurements but its expensive and doesn't stick well. For head[hones I use dynamat - cheap, easy to cut, and stays in place. It's not as potent per amount as sorb, but I like it. Use it to control vibrations and to try and get headphones to sound similar to acoustic suspension bass with a Q of .707 - roughly.

I use it on all my cans in order of most to least: HE-500, MD-4XX, HE-5LE, HE-6 SE v1 (all HFM primarily for bass Q) & Senn HD-600 (the body vibrates), and yes the bass is cleaner. Whatever is missing from those treatments and open air bass loss is replaceable by EQ, but no longer under damped bass and amusical vibrations.

i use self gluing sorbothane patch.... They glued so well and stick, after many years they are not easily removable.... Then no problem for me.... Sorb absorb vibration and transform some % of these vibrations absorbed in heat.... Dynamat damp nothing else and will change more the timbre...

I also use some Fo.Q tape Ta-32, a japanese product which adress more high frequencies.... It complement sorb....

 

[bagwell359]

i use self gluing sorbothane patch.... They glued so well and stick, after many years they are not easily removable.... Then no problem for me.... Sorb absorb vibration and transform some % of these vibrations absorbed in heat.... Dynamat damp nothing else and will change more the timbre...

I also use some Fo.Q tape Ta-32, a japanese product which adress more high frequencies.... It complement sorb....

I make custom feet with Sorb duro 70 washers among other things. I use small amounts on some of my headbands. Sorb sticks on flat surfaces, and leather/plastic well, but its not so good on metallic curved surfaces I have found. Someone mentioned the Fo.Q tape recently - seems interesting. I can treat 25 headphones for 35 bucks worth of dynamat, so tuning/adjustments and sending some to friends is painless. Changing the vibrational level of an object does indeed change its timbre - basic physics.

The big point is that there are multiple materials and methods that accomplish the goal, and more modders and careful listeners should consider trying it out.

Interested in your 340 mods. I heard them unmodded and un-EQ'd and liked some aspects of them, but found issues.

 

[timb5881]

I have been trying sorbothane in my Stax SR0002 iem. Currently I have the CS-1 caps on with a bit of cotton inside and a tab of sorbothane on the outside of each ear cup. The cotton improves the bass a keeps the hi frequencies from getting bad. The sorbothane seems to clean a bit of the midrange.