Fostex T50RP Incremental Mods and Measurements

[MuZo2]

Great, keep us posted.

 

[bluemonkeyflyer]

  I wanted to offer a thanks to all people involved in this project. I'm not done, but I just crossed from 'OK' to "Wow!'.
 
I'm powering the Fostex using a tweaked Panda with 0Ohm output resistance and +3db gain. At home I use a Macbook Pro into a Gamma 1/2 DAC; at work I use an iPhone 5 into a reconfigured grubDAC. My reference headphone is a Lawton L2 Denon AHD2000.
 
I'm sure it has been done a thousand times before, but here is my mod history and impressions:
T50RP, Stock - Uncomfortable, sensitive to ear position, and all mid-range. Moving on...
T50RP, SRH840 pads - Pads are a touch warm, isolate well, and are much more comfortable than stock. The lows and highs start start to come in, but frequency balance is still mid-heavy.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, closed baffle port - Further refinement to the low/high frequencies. While the bass is not big, it is going low. The highs are playing from behind a veil. Overall decent, but the bass is not "fun" and the highs do not sparkle.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, closed baffle port, Silverstone in floor wells, ~10g Newplast mass loading - The Silverstone caused a severe sensitivity drop. The bass may have improved, but it is merely there. The veil over the highs is even more pronounced. Don't stay here.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, open baffle port, Silverstone in floor wells, ~10g Newplast mass loading - No perceptible change.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, open baffle port, Silverstone in floor wells, Creatology adhesive felt in top/bottom of cup, ~10g Newplast mass loading, 19mm treble reflector (shiny magazine cover), 45x52mm (w/ 4x3mm bass holes) Creatology stiffened craft felt over driver - The highs have snapped into place; the bass tight, low, and fairly balanced with the rest of the frequency range. At this point, these cans are no longer decent but quite impressive.
 
Aesthetic/comfort mods:
V-MODA cable - Hey, the static is gone!
MrSpeakers Leather Comfort Strap - Oh so comfortable! No more headband hotspots!
 
Next up:
I have Dynamat ready to go around the ear side of the drivers. I also plan on swapping the cotton balls for fiberglass/rolled cotton.
 
I have REW at home, as well as the Panasonic mics, however I have not built my power supply yet. Eventually I will measure my build and continue to tweak.

 
I look forward to seeing your graphs and more impressions.
 
I apprecieate your systematic and "incremental" approach.  

 

[nick n]

^ consider putting Creatology adhesive felt over the dynamat on the earside also.   Thanks for the post!

 

[micmacmo]

  I'm sure it has been done a thousand times before, but here is my mod history and impressions:
T50RP, Stock - Uncomfortable, sensitive to ear position, and all mid-range. Moving on...
T50RP, SRH840 pads - Pads are a touch warm, isolate well, and are much more comfortable than stock. The lows and highs start start to come in, but frequency balance is still mid-heavy.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, closed baffle port - Further refinement to the low/high frequencies. While the bass is not big, it is going low. The highs are playing from behind a veil. Overall decent, but the bass is not "fun" and the highs do not sparkle.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, closed baffle port, Silverstone in floor wells, ~10g Newplast mass loading - The Silverstone caused a severe sensitivity drop. The bass may have improved, but it is merely there. The veil over the highs is even more pronounced. Don't stay here.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, open baffle port, Silverstone in floor wells, ~10g Newplast mass loading - No perceptible change.
T50RP, SRH840 pads, RiteAid cotton balls (6 per cup), 1x3mm base port, open baffle port, Silverstone in floor wells, Creatology adhesive felt in top/bottom of cup, ~10g Newplast mass loading, 19mm treble reflector (shiny magazine cover), 45x52mm (w/ 4x3mm bass holes) Creatology stiffened craft felt over driver - The highs have snapped into place; the bass tight, low, and fairly balanced with the rest of the frequency range. At this point, these cans are no longer decent but quite impressive.
 
Next up:
I have Dynamat ready to go around the ear side of the drivers. I also plan on swapping the cotton balls for fiberglass/rolled cotton.
 
I have REW at home, as well as the Panasonic mics, however I have not built my power supply yet. Eventually I will measure my build and continue to tweak.

Wow, way to go! Lots of good work here. I especially admire your ability to acknowledge that some changes don't make any change! 
 
REW is invaluable. It's worth the time and effort; it helps confirm what you hear by letting you "see" it too. 

 

[bluemonkeyflyer]

  Wow, way to go! Lots of good work here. I especially admire your ability to acknowledge that some changes don't make any change! 
 
REW is invaluable. It's worth the time and effort; it helps confirm what you hear by letting you "see" it too. 

micmacmo knows of what he speaks.

 

[bluemonkeyflyer]

I did some tests, today, using T20RP mkII and venting variations with Shure pleather 840 pads. Measurements suggest that inner wall pad enlargement has less of an effect than external pad wall venting.
 
I suspect that velour pads may offer the venting "sweet spot" without having to resort to cutting holes in the outer pad walls. Does anyone have any experience with velours on T50RP?

 

[peter123]

I did some tests, today, using T20RP mkII and venting variations with Shure pleather 840 pads. Measurements suggest that inner wall pad enlargement has less of an effect than external pad wall venting.

I suspect that velour pads may offer the venting "sweet spot" without having to resort to cutting holes in the outer pad walls. Does anyone have any experience with velours on T50RP?

Yep, I've got the velour HM5 pads on one of my pairs and that's the best I've ever heard them. The bass is still nice and deep. I think the memory foam in the pads really is what seal the deal.

They're pretty hard to fit on the first couple of times though

 

[bluemonkeyflyer]

Yep, I've got the velour HM5 pads on one of my pairs and that's the best I've ever heard them. The bass is still nice and deep. I think the memory foam in the pads really is what seal the deal.

They're pretty hard to fit on the first couple of times though

Thanks, Peter. I need to order some different velours to try out.

 

[peter123]

Thanks, Peter. I need to order some different velours to try out.

You're more than welcome. I've pretty much followed the DBV3 tutorial and just switched the Shure pads with the HM5 velours. I couldn't be happier with the way then sound, perfect for my preferences.

 

[bluemonkeyflyer]

You're more than welcome. I've pretty much followed the DBV3 tutorial and just switched the Shure pads with the HM5 velours. I couldn't be happier with the way then sound, perfect for my preferences.

Very happy to hear this! Good for you.

 

[peter123]

Very happy to hear this! Good for you.

Thanks, I'm happy to

 

[c61746961]

The HPAEC1540 (alcantara) should be worth a try too, sadly they're quite expensive.

 

[bluemonkeyflyer]

The HPAEC1540 (alcantara) should be worth a try too, sadly they're quite expensive.

Thanks for the tip.

 

[PETEREK]

I just ordered my alcantara pads for $40 the other day. Hopefully they're worth it.

 

[Thujone]

The Alcantaras are extremely comfortable, I use them on my HE-4. I'll have to give them a try on the T50RP at some point.