[plin]

There are lots of modifications for many orthodynamic headphones in the huge ortho thread regarding various damping suggestions. It seems that damping is important for tuning ortho sound. There is, also, at least one damping mod for LCD-3.
There is a very good HE-500 thread for ear pad mods, but nothing for damping mods, so I thought it would be nice to open one. 
Please, do not post any cable mods here. 
 
In HE-500, like other HifiMan headphones, the metal mesh that protects the back of the headphone can be easily removed, revealing their driver’s back. Instructions given by the man who designs HifiMan here.
 
Revealing the back of the headphone’s driver lets you easily place additional damping or replace the original with a new one.
Please note that it is not a good idea to let the driver mechanically unprotected. Dust and little hairs may easily accumulate but the worst are the metal particles. Any small magnetic metal object that comes near the very strong magnets will inevitably be stuck inside them, causing probably irreversible damage to the thin membrane of the driver. So, please, be very careful and never leave the back of the driver unprotected for a prolonged time.
You can also add additional damping in front of the driver. Keep in mind that the old velour pads appear to have more damping (more dense fabric in front of the driver) than the new ones.   
 
Please try any mods with your own risk.

 

[plin]

When I first listened HE-500 a resonance bothered me. I found the back black metal mesh to be the source of this resonance. I had the opportunity to audition a newer HE-500 in which the mesh was made from a thicker metal and the resonance was less annoying. That is the reason, probably, that I am the only one which seems to have noticed this resonance.
 
When removing this metal mesh, leaving the back of the driver with no protection and damping, I liked the new sound from across the spectrum. So I decided to find a simple protection that doesn’t muffle the sound of the driver much. 
A light but reasonably dense woven fabric is tulle netting, so I used this. You cannot precut it and then place it on the back of the driver, because the fabric won’t have any mechanical support. So I just enclose the plastic ring with tulle net, place the plastic ring in place and then cut the remains of the net. 
It is wise to leave a small portion of the net on the rim uncut, because it would be easier to stretch the net if it is necessary.
 
   
 
 
   
 
 
What has changed with this mod?
The sound is more dynamic, energetic, involving, with faster attack. 
Soundstage seems more forward, open, more 3 dimensional, bigger and space cues are more apparent (but I really do not care about soundstage, so please take my observations here with a grain of salt). 
It seems that high frequencies (above 3KHz) are about 2 -3 dB more in level which give HE-500 more high energy  (some will probably not like that).
The annoying (for me at least) 300Hz ringing is completely gone, making bass more defined. Bass seems clearer and has a bit more slam. 
The perceived loudness has increased. But the sound is not so ‘polite’ anymore; HE-500 do rock better, but may induce fatigue more easily. These days I haven’t got more than 30 minutes spare time to enjoy music, so I cannot really check if this mod makes long listening sessions unbearable. For only 30 minutes there is no problem.
EDIT: no fatigue even after 3 hours cont. listening.
 
Disadvantages with this mod:
Mechanical protection of the driver is compromised with this mod. The protection offered by the fabric is just enough for small objects but not for anything else. So, please, keep your HE-500 double protected if you decide to try this mod.
It is not easy to put the fabric back once you removed it!
The fabric I used is microphonic, anything that rubs or touches it (like when touching the headphones for readjusting their place) makes an annoying hissing sound.
It is with no doubt ugly, it would have be much more beautiful if I used a black fabric, but because I do not share my headphones and I do not wear them in public I do not care about looks, I care only for good sound. 
 
The rest of the thread is for anyone else to share his/her experience about this mod or any other damping mod about HE-500. Please, do not post cable mods here. Thank you. 
 
EDIT: a much better mechanically protective work performed by Jerg here. It is for HE-400, but should apply to HE-500 too, because they have the same grill/mesh construction.

 

[Tilpo]

Awesome idea.

I do think the disadvantages outweigh the advantages though. I wouldn't buy such an expensive piece of equipment just to make it look like that.
But that's just me, perhaps. Sound quality is the most important factor.

 

[reddragon]

wouldnt dust get in there eventually? and will the headphone sound like he400 after modding? i have neither but it fits the description of a he400 by other headfiers the way you describe the headphone after modding

 

[plin]

Quote:

wouldnt dust get in there eventually? and will the headphone sound like he400 after modding? i have neither but it fits the description of a he400 by other headfiers the way you describe the headphone after modding

Small particles of dust do get in, even with the stock metal mesh. If the tulle net is very fine, then I do not think will be a problem.
HE-400 has completely different drivers, it is not something like HD-600 and HD-650.

 

[Tilpo]

Small particles of dust do get in, even with the stock metal mesh. If the tulle net is very fine, then I do not think will be a problem.
HE-400 has completely different drivers, it is not something like HE-600 and HE-650.

HE-600, HE-650?? :blink:

 

[plin]

Quote:

Awesome idea.
I do think the disadvantages outweigh the advantages though. I wouldn't buy such an expensive piece of equipment just to make it look like that.
But that's just me, perhaps. Sound quality is the most important factor.

 
You certainly do have a point.
 
I suspect most people will try removing / alternating the fine fabric in front of the driver or just add more damping on the back of it, without removing the metal mesh.

 

[reddragon]

Quote:

HE-600, HE-650??

 
 
+1, 600 and 650????

 

[plin]

Quote:

HE-600, HE-650??

LOL, sorry, my typo. I meant Sennheiser HD-650 and HD-600 which lots of folks claim they have the same drivers.
I corrected it to the original post, thank you.

 

[reddragon]

ok i dont mean they have the same drivers, im sure they dont. my point is the way you describe the sound of he500 after modding is close to the description of how some headfiers describe the sound of a he400

 

[plin]

Quote:

ok i dont mean they have the same drivers, im sure they dont. my point is the way you describe the sound of he500 after modding is close to the description of how some headfiers describe the sound of a he400

I haven' t heard HE-400, so I cannot comment on that, maybe others who do have and try the mod can enlighten us.

 

[wje]

Quote:

ok i dont mean they have the same drivers, im sure they dont. my point is the way you describe the sound of he500 after modding is close to the description of how some headfiers describe the sound of a he400

 
Wait.  So, you're indicating that people are buying the $699 HE-500s and applying a $1.00 modification and then they can have the same sound as the $399 HE-400s?  I just wanted to ensure that I read that correctly.
 
Having both headphones in my collection, I can state that they both have their unique points.  I love them both.  However, I will not perform any modifications to my HE-500 because it has a unique signature that pleases me.  Then, there is the HE-400, also a unique signature that I like, too.

 

[plin]

Quote:

 
I will not perform any modifications to my HE-500 because it has a unique signature that pleases me.  Then, there is the HE-400, also a unique signature that I like, too.

 
 
Any modification in the overall damping of the headphone will inevitably change its sound signature. So, if someone is pleased with the HE-500 sound signature there is no need to mod it. 
 
On the other hand, just removing the metal mesh is so easy, it takes just a couple of seconds, and it is completely reversible. Anyone can try removing it and judge for themselves if they like the new sound. I, too, liked the sound signature of the unmodified HE-500, but when I auditioned it with the back metal mesh removed I liked it more! 

 

[reddragon]

Quote:

 
Wait.  So, you're indicating that people are buying the $699 HE-500s and applying a $1.00 modification and then they can have the same sound as the $399 HE-400s?  I just wanted to ensure that I read that correctly.
 
Having both headphones in my collection, I can state that they both have their unique points.  I love them both.  However, I will not perform any modifications to my HE-500 because it has a unique signature that pleases me.  Then, there is the HE-400, also a unique signature that I like, too.

 
 
i have neither but according to what i read, that will be my guess... well you have both, if you dont mind risking yours you can try the mod and judge for yourself. plin said its completely reversible...

 

[jerg]

Quote:

 
Wait.  So, you're indicating that people are buying the $699 HE-500s and applying a $1.00 modification and then they can have the same sound as the $399 HE-400s?  I just wanted to ensure that I read that correctly.
 
Having both headphones in my collection, I can state that they both have their unique points.  I love them both.  However, I will not perform any modifications to my HE-500 because it has a unique signature that pleases me.  Then, there is the HE-400, also a unique signature that I like, too.

 
To be fair, the HE500s have a significantly more even midrange all the way up to lower treble, compared to HE400s (which have a bump or two between 600~1000 Hz, and a pretty big dip between 2-4kHz). If the mod amps up the HE500 bass and softens its treble, then it at least on paper would have the 'fun' factor of HE400s without losing its midrange refinement.