Just listened to some Fostex T50RPs today... WOW!

[dBel84]

my favourite tuning felt is Italian cashmere ..dB

 

[4nradio]

Ditto! I too removed the white material from the driver back and found the mids improved. Now I'm experimenting with 3M Micropore tape covering all but the center "cell" (open rectangle in the grid) on the back of the drivers, and trying various materials in that center cell. Currently the center cells are filled with a small block of blue Scotchbrite pad.
 
With the driver back completely covered with one layer of Micropore, the bass was drastically reduced (but still better mids/highs than stock)... so, I left the center cell open for tuning purposes. 
 
I colored the white Micropore tape with a black felt tipped marker to improve the visual appearance when seen through the ear cup grills.  
 
I also have the cloth from the from of the driver removed, with only the cloth on the JMoney pads between the drivers and my ears.
 
BTW, these Fostex T50rp drivers are inside of an open style donor headphones (modified JVC HA-RX900). The sound is very nice... no loss of bass with these open style T50rp's! The change to open style also seemed to be the key to reducing the rolled off treble noticed previously when they were closed cups. 
 

 

[Bjarne]

Wow! 

 So you solved the comfort problem, too! 

 
More pictures would be really nice!!! 

 

[Stitch]

I'v been listening to the T50Rp for a few weeks now since i got it from Shamu144. I really like it. Its odd though.
Its not as clear and lacks soundstage and higs compared to the DT880. However, its punch and speed is just very nice and accurate. The drums really come through, the guitarwork on most heavy/prog metal sounds detailed and spot on. 
 
On the GS-1 they are really a great set of cans. If it wasnt for games the DT880 would be sitting workless. The SR325is are already for 3 weeks now 

I've been drooling over some Naim gear lately and can only wonder what the famous Naim PRaT will do to these cans.....
 
 
 

 

[Bellerophon]

Thanks so much to all the contributors for a very interesting thread.
 
I received a pair of the TP50RP's yesterday after reading through this epic thread a couple of weeks ago and listened to them for about 3 hours last night.  Connected directly to line out from a typical ASUS implementation of the Realtek ALC1200 on my computer, I have to say that I was very pleasantly surprised by these cans.   Without any modifications, I found them to pretty well balanced across the frequency range though, perhaps, just a little shy on bass.  I particularly liked the non-fatiguing un-etched nature of these phones and found myself really involved in the music - always a good sign in my view. They have a similar signature to my mini magnepan planars with less dynamics but more extension at the low end.   Comfort was good for my head with just enough side pressure to make a good seal. 
 
I'll probably add some modelling clay to the baffles per many recommendations in this thread this weekend but I was also thinking about adding a DAC/amp to improve that source quality to get a little more dynamic range.  On paper the Matrix Mini-I DAC/amp seems like a reasonable choice with 50 ohm phones with 98db/mW sensitivity based on my calculations and the price seems ok for a pair of $75 phones. 
 
Is it worth investing in a DAC/amp for these?  If so, is the Matrix Mini-I a good choice?  I know this is hard to determine because everyone has a different yardstick when measuring these things but how much of difference do the mods really make?  I'm not in any way shape or form a headphone afficionado, in fact I generally dislike them, but I have owned or listened to some very rare and highly prized two channel high fidelity equipment over the years and I play several instruments so I do have a bit of an idea w.r.t the sound I'm looking for.
 
 
 
 
 
 

 

[BattleBrat]

Alright, just finished the earcups, I used Paxmate+ ON TOP of Dynamat (I call it Paxmat) and lined the earcups with it. I also removed the felt covering the vent, for the time I'll leave it open and use tape on the outside till I figured how I want it. 


I also bared the drivers and put in plasticine (messy stuff, I wonder if stripped dynamat is cleaner... next pair..) any felt suggestions are appreciated, please tell me how each felt changed the sound, and keep in mind I have bare drivers

 

[HDMan]

Your not going to believe it, I found an old lathe in the back shed and it works, made my own tools and already spun a rough copy. If they come out good I might knock out a few for the Headfier's.
 
 

 

[mrspeakers]

Felt makes the sound a bit smoother and less edgy, though the effect varies a bit by type, and what you need depends on which ear pads you use.  I really like the Shure 840 ear pads; easy to get, comfy, better bass and only $18.  The Sony 5000 pads are leather but actually make my ears sweat a bit more, and are a lot more expensive.

 

[BattleBrat]

On my B&W Matrix 805's I bought this box from B&W. This box is called a "Bass Alignment Filter" it purpose? to cutoff low frequencies the speakers physically cannot reproduce, Why? because over extension of the bass driver results in loss of detail and it affects higher frequency response of the driver. You see Fostex couldn't install a "Bass alignment filter" box, so they put this white material (try blowing air through it, restrictive huh?) to limit the movement of the driver, and keeping the bass in check, which is why the bass gets boomy when you remove it. Felt isn't the only option we should be considering, we should look into cloth, denser the better, micropore works too. but cloth would be easier to install, and all you would really have to check is how restrictive the cloth is (to airflow) you can install cloths of varying restriction and tweak the sound to your liking.
this is my theory anyway....

 

[joelpearce]

Quote:

On my B&W Matrix 805's I bought this box from B&W. This box is called a "Bass Alignment Filter" it purpose? to cutoff low frequencies the speakers physically cannot reproduce, Why? because over extension of the bass driver results in loss of detail and it affects higher frequency response of the driver. You see Fostex couldn't install a "Bass alignment filter" box, so they put this white material (try blowing air through it, restrictive huh?) to limit the movement of the driver, and keeping the bass in check, which is why the bass gets boomy when you remove it. Felt isn't the only option we should be considering, we should look into cloth, denser the better, micropore works too. but cloth would be easier to install, and all you would really have to check is how restrictive the cloth is (to airflow) you can install cloths of varying restriction and tweak the sound to your liking.
this is my theory anyway....

but dense materials ALSO work as a giant driver-covering reflex dot.  Goodbye, boom... hello, sizzle.  To some extent, I think you're right, which is why I had to cover most of the vent holes to control the bass, but the result is a much more exciting sound than I could ever get with the stock configuration OR micropore/transpore.  I did get some furniture dust cover cloth at one point and tried it, but it sounded truly awful. 
 
 

 

[bluemonkeyflyer]

Nice job and interesting hypotheses to systematically test and then report.  : )
 
Quote:

On my B&W Matrix 805's I bought this box from B&W. This box is called a "Bass Alignment Filter" it purpose? to cutoff low frequencies the speakers physically cannot reproduce, Why? because over extension of the bass driver results in loss of detail and it affects higher frequency response of the driver. You see Fostex couldn't install a "Bass alignment filter" box, so they put this white material (try blowing air through it, restrictive huh?) to limit the movement of the driver, and keeping the bass in check, which is why the bass gets boomy when you remove it. Felt isn't the only option we should be considering, we should look into cloth, denser the better, micropore works too. but cloth would be easier to install, and all you would really have to check is how restrictive the cloth is (to airflow) you can install cloths of varying restriction and tweak the sound to your liking.
this is my theory anyway....

 

 

[bluemonkeyflyer]

JoelP,
 
I don't recall...What material/configuration did you settle on?
Quote:

but dense materials ALSO work as a giant driver-covering reflex dot.  Goodbye, boom... hello, sizzle.  To some extent, I think you're right, which is why I had to cover most of the vent holes to control the bass, but the result is a much more exciting sound than I could ever get with the stock configuration OR micropore/transpore.  I did get some furniture dust cover cloth at one point and tried it, but it sounded truly awful. 
 
 

 

 

[joelpearce]

I think I've just got a thin layer of craft felt behind there.  Vents 75% closed. baffle vent sealed, but I'm using the SA5000 pads.

 

[HDMan]

Any tutorials to recabling the T50RP's?

 

[BotByte]

Quote:

Any tutorials to recabling the T50RP's?

Solder inside wiring through hole with a nice round of a cable tie.
 
recable, unless silver, will not improve sound quality. It's a debated thing here, but to my unbiased ears, it makes no difference.
 
Still, it's fun and you get to customize your cans more