Fostex T50RP modification summary links
Sep 25, 2011 at 12:27 AM Post #47 of 87
@ joelpearce. Thanks for sharing your ingenuity, Joel. I was considering using damping material in the cups to mop up some of the resonance I hear. Thanks for actually carrying through on the notion and validating the idea. I see you used a novel sound absorber over the driver (the Roxul mineral wool). I'm wondering if you considered or tried other materials instead of the paxmate in the cups? I'm thinking of glass wool or melamine foam here. (I tried melamine very early on, before I dampened the baffle, but discounted it out of hand. Now I'm wondering if I was premature.)
 
Sep 25, 2011 at 6:42 AM Post #48 of 87
I have used a fair number of materials to line the back of the cups: Felt, acoustic foam, cheap foam, blu-tack, closed-cell foam, other types of felt, plastiscene, quilt batting...
 
There's a reason that everyone's using Paxmate these days.  It does kill vibrations, while also providing very good damping value without taking too much space.  I'm not sure it would work as well trying to fill the whole space with the insulation.  In the end, I think it's important that there's still some air in there.
 
Sep 25, 2011 at 1:59 PM Post #49 of 87


Quote:
I have used a fair number of materials to line the back of the cups: Felt, acoustic foam, cheap foam, blu-tack, closed-cell foam, other types of felt, plastiscene, quilt batting...
 
There's a reason that everyone's using Paxmate these days.  It does kill vibrations, while also providing very good damping value without taking too much space.  I'm not sure it would work as well trying to fill the whole space with the insulation.  In the end, I think it's important that there's still some air in there.

 
Very nice job, Joel.  How does it sound compared to other mods/materials you've done?
 
Does the mineral wool insulation "breathe" at all?
 
 
 
Sep 25, 2011 at 2:15 PM Post #50 of 87
Thanks, Joel. I think I'll be adding a butyl dampener to the cup myself. I still hear the occasional resonance ring.
 
I'm not entirely clear on the net audio effect of removing the white felt on the driver. What was your experience, Joel?
 
Quote:
I have used a fair number of materials to line the back of the cups: Felt, acoustic foam, cheap foam, blu-tack, closed-cell foam, other types of felt, plastiscene, quilt batting...
 
There's a reason that everyone's using Paxmate these days.  It does kill vibrations, while also providing very good damping value without taking too much space.  I'm not sure it would work as well trying to fill the whole space with the insulation.  In the end, I think it's important that there's still some air in there.



 
 
Sep 25, 2011 at 3:02 PM Post #51 of 87


Quote:
 
Very nice job, Joel.  How does it sound compared to other mods/materials you've done?
 
Does the mineral wool insulation "breathe" at all?
 
 


Given how itchy it is, I didn't try to blow through it or anything.  It's pretty lightweight, though, so I suspect it breathes quite a bit.
 
Whether it's the additional material or the pressure against the driver, this is the best treble I've had with these mods by a long shot.  Once that material on the back of the driver is removed, it's really hard to get a good level of treble that extends all the way up.  This version is great, though, nice and sharp but not harsh at all.  It's hard to quantify the difference here, but it's definitely the best.  They are a bit more forward, and it emphasizes the speed that orthos are capable of delivering.  The soundstage seems a bit more coherent as well, probably because I've finally gotten rid of that midbass hump  It's pretty big, too, which I think might be a perceived larger cup volume with the rock wool. 
 
Some people might find this setup a bit too bass-heavy, but it doesn't impact the rest of the sound range, similar to what I've experienced with the Thunderpants so far.  This is some of the best headphone bass I've heard, though.  The bass has speed and impact, and you can hear where it is coming from in the sound mix. 
 
Too bad it's hard to get the Roxul in small quantities... I had some around from my renovations this summer.
 
 
Sep 25, 2011 at 3:14 PM Post #52 of 87


Quote:
Thanks, Joel. I think I'll be adding a butyl dampener to the cup myself. I still hear the occasional resonance ring.
 
I'm not entirely clear on the net audio effect of removing the white felt on the driver. What was your experience, Joel?

 

This is going to be hugely unscientific.  While that material is quite thin, it isn't very open, which does a couple thing: it acts as a bit of a reflex dot, and it limits the amount of air available to the driver to move.  Driver movement restriction can be a good thing, because it keeps the sound polite and controlled, but it also creates that sterile, polite sound signature of studio headphones.  When you get rid of that material, the sound really bloats.  It gives the T50RP a tremendous amount of energy, but it also sounds uncontrolled and a lot slower.  More than anything, it completely changes how you have to dampen the cups to get a good sound.  With the cloth there, all you really need to do is get rid of cup resonations, and that thin sheet takes care of:
a)maintaining frequency balance
b)reflex dot for treble
c)preventing an unwanted level of driver movement
 
As soon as that comes off, you need to take care of those three things with different materials, which is a lot more complicated.
 
For me, the question has always been how to get that raw, unbridled energy of the naked drivers, but find a way to control the sound without putting something on the driver that stifled the fun factor.  For a long time, I've been using my opaque wool felt on the driver because the cheap felt simply isn't enough--you end up with no treble, and mounds of uncontrolled bass that spills over into the midrange something awful.  What this combination seems to do is still allow the driver to move fairly well, while reflecting enough treble and absorbing enough bass to create some balance.
 
Sep 25, 2011 at 3:59 PM Post #53 of 87
Ardilla et al.,
 
I have a request/suggestion:  This is good stuff but I think it should be posted over on the "Just Listened to Fostex Mod forum" and keep this forum reserved  just for links.  This would keep this forum relatively short and avoid redundancy with the other forum.  Some people may miss longer posts about modding  the T50RP unless they keep up with both threads.
 
Just a thought.
 
Sep 25, 2011 at 4:31 PM Post #54 of 87


Quote:
Given how itchy it is, I didn't try to blow through it or anything.  It's pretty lightweight, though, so I suspect it breathes quite a bit.
 
Whether it's the additional material or the pressure against the driver, this is the best treble I've had with these mods by a long shot.  Once that material on the back of the driver is removed, it's really hard to get a good level of treble that extends all the way up.  This version is great, though, nice and sharp but not harsh at all.  It's hard to quantify the difference here, but it's definitely the best.  They are a bit more forward, and it emphasizes the speed that orthos are capable of delivering.  The soundstage seems a bit more coherent as well, probably because I've finally gotten rid of that midbass hump  It's pretty big, too, which I think might be a perceived larger cup volume with the rock wool. 
 
Some people might find this setup a bit too bass-heavy, but it doesn't impact the rest of the sound range, similar to what I've experienced with the Thunderpants so far.  This is some of the best headphone bass I've heard, though.  The bass has speed and impact, and you can hear where it is coming from in the sound mix. 
 
Too bad it's hard to get the Roxul in small quantities... I had some around from my renovations this summer.
 


So, I wonder if by removing the white felt we have to replace it with something that will serve a similar purpose and that either:
 
1) allows less air flow/driver excursion and results in more treble-less bass  ---> do this if you like hotter cans
 
2) allows more air flow/driver excursion and results in less treble-more bass ---> do this if you are a bass head
 
3) allows about the same air flow/driver excursion and results in no significant change in the frequency response ---> then you should leave it alone and avoid re-inventing the wheel
 
 
Sep 25, 2011 at 10:17 PM Post #55 of 87
+1
 
Quote:
Ardilla et al.,
 
I have a request/suggestion:  This is good stuff but I think it should be posted over on the "Just Listened to Fostex Mod forum" and keep this forum reserved  just for links.  This would keep this forum relatively short and avoid redundancy with the other forum.  Some people may miss longer posts about modding  the T50RP unless they keep up with both threads.
 
Just a thought.



 
 
Sep 26, 2011 at 1:28 AM Post #56 of 87
Are there any other cables that you guys have found that work rather well aside from the one already mentioned in the topic? I plan on rebuying some T50's to do some modding but I loathed the stock cable and don't quite want to do a full out recable. I also think adding more cables to this topic would make this a beefier summary.
 
 
 
Sep 26, 2011 at 1:29 AM Post #57 of 87


Quote:
Are there any other cables that you guys have found that work rather well aside from the one already mentioned in the topic? I plan on rebuying some T50's to do some modding but I loathed the stock cable and don't quite want to do a full out recable. I also think adding more cables to this topic would make this a beefier summary.
 
 


Why did you hate the stock cable? I have found it to be more than adequate...
 
 
Sep 26, 2011 at 1:38 AM Post #59 of 87


Quote:
I tend to use a smaller amp more often than my full fledged home amp. I have an adapter but I would just prefer to simplify a bit and have a cable that ends in a 3.5mm plug.


I know Rat Shack sells an extension adapter that has a 3.5 male plug on each end. It should fit the Fostex but the plug will protrude a bit more than the stock plug but it should solve your problem.
 
 

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