Just listened to some Fostex T50RPs today... WOW! - Page 661

It looks tempting but not the kind of mod you can easily fix if things go wrong.  I'll stick with the mostly reversible mods for now...
 

true, maybe something to try on the t20 instead. Looks like I gotta sell my shure 840s afterall...I need some disposable t20s!

This is my first post here in a long time, but I've managed to catch up with some quick skimming

I've been playing with mods in the realm of BMF's DBV setups and I've hit a snag. I cannot figure out how to kill a treble peak which is causing ear-piercing sibilance. I would also like to bring down the upper mids which are making my T50RPs sound like a pair of tin cans cupped over my ears (slight exaggeration). I've tried various cotton thicknesses and few transpore square sizes/patterns on the ear-side of the baffle with limited success. Other mods that I've tried include: removing cotton/fiberglass fill, cutting bass holes in the driver felt (various sizes), removing treble reflectors, etc.

This is my current setup:
- 840 pads
- connectors on driver leads to reduce stress on solder joints while modding
- (2) 1ohm resistors on the left driver leads (for vol. balance)
- Paxmate cup floor with Paxmate ribs
- felt on raised cup floor surfaces
- Paxmate cup-to-baffle seal (to be replaced)
- hot glue seals for the cable and jack entry/exit points
- 5 or 6 ply RiteAid cotton fill
- Newplast flush baffle loading
- 1.5 x 3mm bass port holes
- (1) ~1mm baffle hole
- Dynamat around driver (ear-side) covered in felt
- crucifix/grid pattern of ear-side transpore
- solid / unmodified driver felt

My next iterations will involve:
1) covering the headband screw cap with felt
2) removing the driver felt completely or trying other materials

Any other ideas?
Edited by Kibble Fat - 1/29/13 at 8:15am

Did you try with other size cup port holes?  I had the same treble issues as you until I 1) removed all of the felt in the cup and replaced with foam, 2) covered the Newplast with 1/8" foam pcs. and 3) Left 2 1/2 of the outside vents open.  I first tried leaving all of the vents open but the bass was a bit muddy and overwhelmed the mids.  With only 1 slot open, the bass was plenty tight but treble seemed to dominate.  I took off all of the felt from the vents and put electrical tape over the slots on the outside until I achieved the perfect balance.  It's amazing how small changes to coverage affect the sound.
 

Today I started a T50rp transplant...

http://www.head-fi.org/t/648893/ortho-transplant-t50rp-drivers-into-v-moda-crossfade-in-progress-lots-of-pictures

Excellent! Thanks for sharing. I look forward to the next update. Good luck.

 

Very cool, hopefully there's enough room for damping.

anybody have some acoustipack lite they can spare or want to go in on buying some?

I have to say that I am amazed by these headphones more each day.  I have a pair of Unique Melody Miracles that cost close to $1k and these modified $100 headphones surpass them in almost every way.  Closed miced (that looks wrong) songs such as Damien Rice and Natalie Merchant sound ethereal.  I haven't gotten this many goosebumps from songs ever before.  I think I might be at the end of my journey. I know I'll never spend the money for LCD-3 or Orpheus so this will probably be it. I used to think th HE-500s were special but these are in a whole different class.  Now I'm left wondering if recabling will be worth the time.

Edited by deadkenny64 - 2/2/13 at 2:35pm

 

That's very high praise for the T50RPs.  Have you had a chance to a/b compare the two headphones?  I ever preferred the HE-500 to D7000 and Ultrasone Edition 8, that would really make them the ultimate closed headphone.

@deadkenny what MOD did you use?

T50RP's are my absolute favorite can too.. My second favorite are pink grados :)

No, I had the 500s about a year ago.  I remember them being my favorite can at the time but my UM Miracles being slightly superior for detail and vocals.  Now my T50RPs are superior to my UMs.

I did a variation of the DBV #3 and the Rastapants notes I read.  The main deviation from the DVB #3 is:

No treble dot

No fiberglass and only 1/2 the amount of cotton.

No felt anywhere on the cup, only foam

Removed felt from front of driver

Added foam to plasticine areas

Opened 2.5 cup vents for perfect amount of bass and extension. One was too little mid bass and all open was too muddy with bass bleeding into midrange.

 

I am using the 840 pads and LFF's headband suspension with leather instead of paper.

Edited by deadkenny64 - 2/3/13 at 9:05am

I will post pictures when I have a chance to sew up the holes, but the best pads that I have heard so far are a pair of LCD-2 rev. 1 pads that I have re-stuffed with memory foam.  Slightly angled for a nice presentation, seal perfectly, and big, beautiful bass.  This is on an unmodified pair right now.  Best bass so far from a quantity standpoint.  They don't have the lowest rumble of some Denon's that I have heard recently, but completely satisfying finally.  Once my paintjob is finished, I will try these pads with my modded pair.

 

I absolutely love the J$ pads for comfort and great sound, but these modified LCD pads seal and sound better for me.   

 

Modded LCD-2 pads > J$ Beyer pads > Shure pads >> Stock pads

Edited by FraGGleR - 2/3/13 at 12:24pm