Fostex T20RP modding
Jul 22, 2008 at 1:16 PM Thread Starter Post #1 of 13

mapstec

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So I finally got my second Ortho:



As I understand this is the version II and can be successfully modded.

The driver:



and finally the cup and the bit of foam that was inside:





My biggest problem right now is that the left side is louder then the right.
Using a different cable did not help, so I am debating if I want to attempt a dual entry recable, or just try to replace the cable between left and right side.

What else, and what mods to this phone do you suggest?
 
Jul 22, 2008 at 1:46 PM Post #2 of 13
Borrowed this from the ortho thread...

T20ModdV2.2.jpg


You can start off with simple things like folded paper towels to act as damping material but felt is preferable.
 
Jul 22, 2008 at 3:03 PM Post #4 of 13
The size of the hole will directly affect the amount of HF, the larger the hole the less bright headphones will be, the chamois is acting as reflex dot in this mod. You can make the hole round as well. I was just lazy and cut it in a rectangular shape.
 
Jul 23, 2008 at 5:59 AM Post #5 of 13
Omg they cheaped out, compared to my vintage T20RP!!!
But i still want to hear them. Theyre cheap enough, i just may pick up a pair anyway.
 
Dec 22, 2010 at 3:22 PM Post #6 of 13
As a newbie to orthodynamic headphones, what are some popular ways of modding the Fostex headphone?
Seems to me adding thick felt behind and in front of the drivers is a popular mod.
Wouldn't this reduce the highs even more?
 
Dec 22, 2010 at 7:19 PM Post #7 of 13
Dec 23, 2010 at 1:10 PM Post #8 of 13
What is the best thickness of felt for the blue and black ones? Where do I buy cheap felt?
What is the purpose of the yellow fake chamois?
 
I tried removing the stock foam and using cotton.
Better bass but sacrificed the top end and clarity, so back to the foam.
 
Dec 23, 2010 at 1:54 PM Post #9 of 13
In respect of felt, you are bound to trial and error, the "felt market" is just too complex. The chamois is to provide backwards sealing (but not 100% airtight). Keep the stock foam in usage!
 
Jan 11, 2011 at 11:17 AM Post #10 of 13


Quote:
In respect of felt, you are bound to trial and error, the "felt market" is just too complex. The chamois is to provide backwards sealing (but not 100% airtight). Keep the stock foam in usage!


Just got a set of T20 v2 a few days ago and did some simple modding. I used folded paper towel behind the stock foam (haven't had a chance to pick up the felt yet) as suggested on the ortho thread, and removable putty around the baffle.  They sound very good! Can you explain what backwards sealing means? I tried using fake chamois behind the foam instead of the paper towels, but prefer the sound with the paper towel. Haven't tried the chamois with the cut out in the center in front of the foam as of yet. How does that improve the sound....which is already very good with the simple paper towel mod.
 
Jan 11, 2011 at 1:12 PM Post #11 of 13
"Backwards sealing" is just a description of the various stuff you place behind the system in order to achieve a reduced air flow (which results in a brighter and less bloated sound). The chamois stuff isn't to be recommended without a hole in the middle, as it reduces the air flow too much then. With the cut hole, you have a "golden compromise" or "the best of both worlds", the outer sealed areas provide reduction (better presence), wheras the punched center lets the air still flow (helps the bass). That's at least the theory behind it.
 
But other stuff (even paper towels) may provides a similar or even better effect, you never know...
 
Jan 11, 2011 at 4:51 PM Post #12 of 13
Thanks...that helps a lot. These are my first orthos, and I can't believe how easy it was to get rid of that boomy bass with a bit of folded paper towel.. They have noticeably more clarity thanks to that. I don't know if the putty on the baffle is having any effect, but I figured since I had some on hand it couldn't hurt. Next I'll probably try to get hold of some felt, and maybe try the chamois with the hole cut out. As you said it was not good without the hole.
 
Quote:
"Backwards sealing" is just a description of the various stuff you place behind the system in order to achieve a reduced air flow (which results in a brighter and less bloated sound). The chamois stuff isn't to be recommended without a hole in the middle, as it reduces the air flow too much then. With the cut hole, you have a "golden compromise" or "the best of both worlds", the outer sealed areas provide reduction (better presence), wheras the punched center lets the air still flow (helps the bass). That's at least the theory behind it.
 
But other stuff (even paper towels) may provides a similar or even better effect, you never know...

 
Jan 12, 2011 at 9:17 AM Post #13 of 13


Quote:
As a newbie to orthodynamic headphones, what are some popular ways of modding the Fostex headphone?
Seems to me adding thick felt behind and in front of the drivers is a popular mod.
Wouldn't this reduce the highs even more?


If you haven't gotten the felt yet, I suggest you try the 'paper towel mod'. I added one more thin layer of paper towel last night and they've improved greatly over stock. Originally I had 4 thin layers, but with the one additional one I think they're probably close to as good as they're going to get. I was going to try to pick up some felt, but they sound so nice now, I may just leave them as is. BTW, these are real cheapo paper towels...not the thicker, more expensive ones. If you try the thicker ones, you'll probably need fewer layers. Definitely worth experimenting with this simple mod, IMO....simple and only costs a couple of pennies! 
happy_face1.gif

 


Quote:
What is the best thickness of felt for the blue and black ones? Where do I buy cheap felt?
What is the purpose of the yellow fake chamois?
 
I tried removing the stock foam and using cotton.
Better bass but sacrificed the top end and clarity, so back to the foam.



 

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