[bluemonkeyflyer]

  It's a TH500RP with new 3D printed baffle and ear cup.

Thanks. Looks great, Jamey.
 
Now, where's my Dremel? I've got a hankerin' to open up some T50RP baffles. Good thing I saved several rear damping membranes for a rainy day.

 

[bluemonkeyflyer]

Re-Measured LCD2 dimensions for Wave Guides
 

 
Rear Side of LCD2:
 
The height of the Stators and the Openings = 5 mm.
 
The width of the Stators and the Openings = 44 mm.
 
The height from the "floor" to the "ledge" where the grille sits = 7 mm.
 
For simplicity, I think the upper opening could be made 8 mm from side to side and the narrow opening at the bottom could be made 3 mm from side to side. 
 
The Ear Side is the same except it's inverted 180 degrees.

 

[SeEnCreaTive]

  I like the feel of the Alcantaras better than the 840s, though I think it might be an 840 under the alcantara material with black stitching instead of white. I can't be sure. Anyway, they isolate really well and almost give the comfort of velours. In terms of sound, I'd say they are almost the same as the 840s. 
 
And thanks! I spent a lot of time on these things.

Are they custom pads? They seem much thicker and more plush then the stock 840 pads.
 
These 840 pads on mine are nice, but I find are a bit uncomfortable. The pleather gets a bit warm, and I think I'd like more cushion, but a softer foam, so the end up roughly the same height when they're on. Also perhaps a bit wider, the inner diameter being the same, but the outer just a bit more. I tend to have my cans on for hours at a time.
 
 Which seems like what those ones seem exactly like.
 
Ive made a pad for my headband, with a bit more stuffing on the sides to spread out force, its helped, but my old cheap sony MA-300s were more comfortable despite the hard plastic headband
 
 
EDIT: Nevermind, heh I just found what pads those are, I look into getting some.
EDIT2: $85 from Amazon, $40 from B&H.... Nearly half the cost of the cans, for ear cushions. I feel confident in my mothers sewing skills. Heh time to make another call

 

[PETEREK]

Are they custom pads? They seem much thicker and more plush then the stock 840 pads.

These 840 pads on mine are nice, but I find are a bit uncomfortable. The pleather gets a bit warm, and I think I'd like more cushion, but a softer foam, so the end up roughly the same height when they're on. Also perhaps a bit wider, the inner diameter being the same, but the outer just a bit more. I tend to have my cans on for hours at a time.

 Which seems like what those ones seem exactly like.

Ive made a pad for my headband, with a bit more stuffing on the sides to spread out force, its helped, but my old cheap sony MA-300s were more comfortable despite the hard plastic headband


EDIT: Nevermind, heh I just found what pads those are, I look into getting some.
EDIT2: $85 from Amazon, $40 from B&H.... Nearly half the cost of the cans, for ear cushions. I feel confident in my mothers sewing skills. Heh time to make another call

Ha yeah they're expensive as hell, I almost bought Alpha Pads instead for another $20 but decided I wanted to try something new instead.

 

[chinook9]

 
Really great to see these.  I haven't done much with my DBV#3 Fostex in a while, but I have been thinking for a couple of years about making an open pair. 
 
Previously I did not have the skills but now I believe I do.  Last winter in Arizona I made 6 or 7 cups for Grados out of various types of wood and developed some skills on the lathe.  I expect cups for the Fostex would be more difficult than the Grados but should be dooable.
 
We head down to Arizona tomorrow so I'll be working on a plan.  If anyone else has made an open Fostex I would love to hear about it.

 

[BobSaysHi]

Lots of good posts since I last logged in.
 
Has anyone measured a stock T50RP driver inside an open housing before? Has anyone attempted to tune something like that? I have a brand new T50RP and a pair of machined open housings that some kind person here sent to me. I'd love to do some graphs if anyone is interested (if they don't already exist).

 

[Congo5]

   
 
Really great to see these.  I haven't done much with my DBV#3 Fostex in a while, but I have been thinking for a couple of years about making an open pair. 
 
Previously I did not have the skills but now I believe I do.  Last winter in Arizona I made 6 or 7 cups for Grados out of various types of wood and developed some skills on the lathe.  I expect cups for the Fostex would be more difficult than the Grados but should be dooable.
 
We head down to Arizona tomorrow so I'll be working on a plan.  If anyone else has made an open Fostex I would love to hear about it.

 You can definitely make cups n baffles on a lathe. BMF posted the dimensions     post #1032
and cut the drivers square hole with a scroll saw or drill and file it...
 
 I do not like anything messing with the backwave  so run them open and naked.
tried a few things and gave up.
 
  My solution is to use EQ and to tune them by ear,and for me this works very very well.

  Yes that is a lot of EQ, it would seem hard to achieve with mods.
I arrived there by A/B ing with Stax Lambda's driven by Kevin Gilmore's excellent KGSSHV
YMMV

 

[chinook9]

   You can definitely make cups n baffles on a lathe. BMF posted the dimensions     post #1032
and cut the drivers square hole with a scroll saw or drill and file it...
 
 I do not like anything messing with the backwave  so run them open and naked.
tried a few things and gave up.
 
  My solution is to use EQ and to tune them by ear,and for me this works very very well.

  Yes that is a lot of EQ, it would seem hard to achieve with mods.
I arrived there by A/B ing with Stax Lambda's driven by Kevin Gilmore's excellent KGSSHV
YMMV

 
Thanks for the link to Keith's post on the dimensions.  That will help. 
 
I expect I will start out with an open back, but first I have to find a reasonably priced headband that will hold the cups which will be quite large.

 

[PETEREK]

   
Thanks for the link to Keith's post on the dimensions.  That will help. 
 
I expect I will start out with an open back, but first I have to find a reasonably priced headband that will hold the cups which will be quite large.

You can find plenty of broken Beyer DTxx0 on eBay that you could steal the headbands from. Beyer sells replacement headband pads on their site if the ones you buy are worn at all.

 

[bluemonkeyflyer]

   
I will try to make two variants for fostex, one with 7 guides like you was thinking and another with each hole rounded separately. But that will be work for next weekend.
 
By the way I just received your diaphragm thanks again for that. Time for sound rebel came back

 
Did the diaphragm work for you with your monolith?

 

[bluemonkeyflyer]

 

 
Really great to see these.  I haven't done much with my DBV#3 Fostex in a while, but I have been thinking for a couple of years about making an open pair. 
 
Previously I did not have the skills but now I believe I do.  Last winter in Arizona I made 6 or 7 cups for Grados out of various types of wood and developed some skills on the lathe.  I expect cups for the Fostex would be more difficult than the Grados but should be dooable.
 
We head down to Arizona tomorrow so I'll be working on a plan.  If anyone else has made an open Fostex I would love to hear about it.

 
Looking forward to what you come up with.
 

  Lots of good posts since I last logged in.
 
Has anyone measured a stock T50RP driver inside an open housing before? Has anyone attempted to tune something like that? I have a brand new T50RP and a pair of machined open housings that some kind person here sent to me. I'd love to do some graphs if anyone is interested (if they don't already exist).

 
Yes, measure up!
 
I've done some infinite baffle measurements.
 

   You can definitely make cups n baffles on a lathe. BMF posted the dimensions     post #1032
and cut the drivers square hole with a scroll saw or drill and file it...
 
 I do not like anything messing with the backwave  so run them open and naked.
tried a few things and gave up.
 
  My solution is to use EQ and to tune them by ear,and for me this works very very well.

  Yes that is a lot of EQ, it would seem hard to achieve with mods.
I arrived there by A/B ing with Stax Lambda's driven by Kevin Gilmore's excellent KGSSHV
YMMV

 Thanks. Will give it a try.

 

[Congo5]

   Does anyone know of a cheaper donor phone to use for mods that looks like the 500RP?
(top or side mounting headband) not center of back like T50, T20 etc.
something that would take a 80mm to 90mm driver?
and maybe be able to use HM5 pads.
 
Thanks

 

[PETEREK]

80-90mm? Damn that's huge. Probably Beyer DTxx0 headphones.

 

[ZGLISZCZ]

   
Did the diaphragm work for you with your monolith?

Hi BMF,
Diaphragm work nicelly, but somehow I cant get to the point where I was with sound tune. I tried transpore tape recently but not 3M you did. sound was kind of weak and there was no bass in it. Can you tell me if 3M transpore let air flow? the one I used doesnt really. I applied some tiny pieces of leather inside driver (bit like Russian Mod) and it seems to remove a bit low mid hump but I changed few other things so Im not really that sure. I will post some pictures soon. I feel like Im stuck. Also somehow I have "behind the curtain" sound. I believe its matter of dampening behind the driver and maybe that I glued black thin felt on ear side (the one that was there originally). Keith, does those cotton pads that you used to secure diaphragm work well as dampening? I tried similar material from dust mask but it didnt work to me. I wish to finish tuning those headphones, I dont want to know how many times I opened them...

 

[bluemonkeyflyer]

  Hi BMF,
Diaphragm work nicelly, but somehow I cant get to the point where I was with sound tune. I tried transpore tape recently but not 3M you did. sound was kind of weak and there was no bass in it. Can you tell me if 3M transpore let air flow? the one I used doesnt really. I applied some tiny pieces of leather inside driver (bit like Russian Mod) and it seems to remove a bit low mid hump but I changed few other things so Im not really that sure. I will post some pictures soon. I feel like Im stuck. Also somehow I have "behind the curtain" sound. I believe its matter of dampening behind the driver and maybe that I glued black thin felt on ear side (the one that was there originally). Keith, does those cotton pads that you used to secure diaphragm work well as dampening? I tried similar material from dust mask but it didnt work to me. I wish to finish tuning those headphones, I dont want to know how many times I opened them...

I'm glad the diaphragm worked for you. If I remember correctly, you removed the rear side stock damping membrane from your drivers. Doing so "let's them Fly" uncontrolled with massive Boomy Bass Bloat, midrange muffling, and squashed treble. In my experience, trying to regain lost ground after this irreversible modification is a cluster FUBAR. I posted some mods that work pretty well in the first post of this thread and the Naked Driver Mod in the T50RP WOW thread.
 
I don't hear any effect with the stock ear side dust cover removed or left on. It's Ultra thin and very air permeable.
 
I've used the cotton pads, like the ones I used to cushion the diaphragm I sent you, successfully as damping material in the All Paxmate Lattice Mod and the Balsa Wood Lattice + Paxmate Lattice Mod. In each of these, I left a 35mm x 35mm "nest" (an opening in the lattice work) directly over the rear of the drivers. I cut the cotton pads to fit this space with good results.
 
3M Transpore Tape is perforated, clear plastic tape that allows for controlled air flow
.
3M Micropore Tape is not perforated and lets minimal, if any air through. It's advertised to "breathe" when used on skin so maybe it breathes a little bit; still has to make it through the adhesive. It's opague white paper tape. You can remove some/all the adhesive by soaking strips of it in acetone and rubbing off the loosened adhesive with your fingers. Let it dry and you may have a more air permeable paper you can glue into place. Another method is to remove the adhesive, let the Micropore dry, then cut to size. Next, cut another piece of Micropore in the shape of a picture frame that slightly overlaps the perimeter of the non-adhesive Micropore. This may allow you to tension the non-adhesive piece over the back of the driver. Others have tried coffee filters, dryer sheets, etc. 
 
I recommend using masking tape to attach baffles to cups when modifying and tuning. This is the best way to prevent stripping the cup threads. For one method to repair stripped cup threads, look in Post #1 of this thread. There's a Table of Contents tab for this.
 
RE: Opening/Closing modification cycles... I feel your pain and applaud your determination.
 
Good Luck!