[ab111]

Very interesting jerg. Great work but is this mostly to tame the treble? I have the he-4s. I'm at the point with my setup that the treble is a non issue for me. If I were to nitpick the sound id like a bit more forward mid presentation.

Mostly this post is to subscribe as I will probably do this mod down the line regardless.

ab111

 

[jerg]

Very interesting jerg. Great work but is this mostly to game the treble? I have the he-4s. I'm at the point with my setup that the treble is a non issue for me. If I were to nitpick the sound id like a bit more forward mid presentation.

Mostly this post is to subscribe as I will probably do this mod down the line regardless.

ab111

Nah, this was more of an accidental discovery I had while trying to tame the treble (which never really worked out), what is outlined here improved the clarity and micro-detail (subtle ambiance and background reverb in music) mainly, and in turn made the overall sound cleaner. It's pretty important for HE500s I think, because they are definitely the slowest-sounding planars from Hifiman.

 

[kard16]

Here's my attempt to make this mod closer to the Audeze Fazer:
 

 
I got really good contact so I'm hoping the adhesive holds them in place, but from the feel of it, they should stay put.  

 

[DefectiveAudioComponent]

  I was recently reading about horn loudspeakers and their benefits compared to other loudspeaker types (increase directivity).Then i got an idea.What if those long felt strips could be triangle shaped and between them would be thin trapezoidal felt pieces at 90 degree angle. Check out these illustrations i made http://imageshack.us/a/img12/1156/8l15.png  and http://imageshack.us/a/img43/1859/tdez.png
In these images you can see,that the shape of free space between two magnet/metal/felt pair is like cross section view of a horn.So basicly i´m thinking that these "little horns" could act as a waveguide directing sound to more narrow area and improving clarity even more.

 
I recall that Grundig used a similar approach for their vintage orthodynamic, by drilling holes in their round disc magnets that were gradually larger from the membrane to the magnet surface.

 

[DefectiveAudioComponent]

 
Here is a picture of the Grundig design - as yo see, the holes are smaller the closer to the membrane it gets.

 

[nick n]

Yamaha also had some chamfered square holes in some drivers.
 
Could also try acoustic foam.
 By the way Creatology makes a thicker foam sheet that is easy to slice with an exacto blade.  And it's cheap. Triangular shapes should be easy to make with it, best to use some sort of jig/guide for the right angle.
 
Just putting that out there

 

[kard16]

So a little update to my experiment in trying to make the felt triangular by pinching it together: it doesn't work.  Two days later, the little strips started to flare out and started blocking the openings.  I guess the adhesive isn't tacky or strong enough to hold it in place.  But, I had another idea.  Michaels had two types of adhesive felt, one was stiff and the other wasn't.  I might try something like this:
 

First, I put the stiff felt on each metal strip, and then I use the thinner felt and curve around it.  This seems like it would actually hold.  

 

[jerg]

  So a little update to my experiment in trying to make the felt triangular by pinching it together: it doesn't work.  Two days later, the little strips started to flare out and started blocking the openings.  I guess the adhesive isn't tacky or strong enough to hold it in place.  But, I had another idea.  Michaels had two types of adhesive felt, one was stiff and the other wasn't.  I might try something like this:
 

First, I put the stiff felt on each metal strip, and then I use the thinner felt and curve around it.  This seems like it would actually hold.  

Alternatively why not just have bottom 3.5mm stiff felt, and top 2.5mm stiff felt also (without doing this wrap-around thing which IMO will never permanently hold), and grind/rub their edges with the technique I outlined in the first post, until the curvature is nice?

 

[kard16]

  Alternatively why not just have bottom 3.5mm stiff felt, and top 2.5mm stiff felt also (without doing this wrap-around thing which IMO will never permanently hold), and grind/rub their edges with the technique I outlined in the first post, until the curvature is nice?

 
That could work too.  I'm getting anxious waiting for MonkeyNutz wooden cups to arrive so in the mean time I may as well experiment.    

 

[jerg]

I compared the back (grill) sides with or without the felt layout, and opted to keep the felt removed. There is no benefit except visual aesthetics, and they seem to introduce a weird treble ringing despite me tapering their edges quite significantly. I think I'll revise the guide slightly to suggest against doing this, at least for HE500.

 

[BikerNickMN]

Just applied this mod to my HE-400s and I am pleased with the result so far.  Seems to have improved the clarity and separation of the music.  It also seems like it has turned down the treble a little bit as well.
 
I used 3.5mm strips of felt on the edges of the plastic supports and 2.5 strips on the rungs running across the magnets.
 
The only other thing I have done to the headphones is removed the cloth from the grills.  I am using the velour pads with the foam rings that came with the pleather pads.

 

[mnarwold]

that it acts as a waveguide too well especially for the treble region, and the end sound was stringent around 10kHz.

 
Hey Jerg,
    Thanks for your work on this. What do you mean by "Stringent" at 10k? I thought the definition was exact or strictly adhered to, but it seems like you're saying there's too much or not enough. I tried the mod tonight and it seems the sound got boosted at 8k and 12k and lowered at 10k, but I didn't think to do a sine sweep right before I did the test, I'm just going from memory that it sounded pretty flat when I did sweeps a couple months ago. I tried to round the corners with a pen, but it doesn't seem to making much of an effect.  I'm not sure if I'm doing something wrong.

 

[jerg]

   
Hey Jerg,
    Thanks for your work on this. What do you mean by "Stringent" at 10k? I thought the definition was exact or strictly adhered to, but it seems like you're saying there's too much or not enough. I tried the mod tonight and it seems the sound got boosted at 8k and 12k and lowered at 10k, but I didn't think to do a sine sweep right before I did the test, I'm just going from memory that it sounded pretty flat when I did sweeps a couple months ago. I tried to round the corners with a pen, but it doesn't seem to making much of an effect.  I'm not sure if I'm doing something wrong.

To my ears it was a ringing introduced in the treble region, made it almost grating-sounding. I was able to ameliorate it by removing all the felt strips off the outer-facing sides of the drivers (I only did those for cosmetic reasons anyway, they never were meant to do anything positive to the sound), and by extensively rounding off the edges for the felt strips on the ear-facing sides of the drivers (with some gentle force using my fingers).
 
Like I hypothesized before, this treble ringing/stringency was perhaps introduced by some unintentional wave-guiding effect.

 

[Soundsgoodtome]

Wow... just when I thought I was done, I find this thread. Looks like I'll need some felt from the arts/crafts store to try this out. At least I'll have something to do after fooling around with the angled Denon pads on the HE4.

 

 

[AstralStorm]

I'd say there are more effective damping materials than felt - but perhaps harder to work with.
 
I'll check: pressed mineral wool, cotton pads, pressed kapok. No fibreglass unfortunately.
 
About attaching - the best thing you can do is lacquer it with an acoustically transparent lacquer without damaging the porous surface. Most elastic lacquers work for this purpose.