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

[bluemonkeyflyer]

Quote:

I guess I used the wrong word.  I am damaging the tops of the screws to the point where it is hard for the screwdriver to grip it well.  

Oh, gotcha. Even so, I've never stripped the screw heads, either. You must have a HARD screwdriver! Or, are you applying enough pressure against the screw heads while maintaining positive pressure with your other hand to compress the baffle to the cup as you open and close?

 

[kalbee]

Oh, gotcha. Even so, I've never stripped the screw heads, either. You must have a HARD screwdriver! Or, are you applying enough pressure against the screw heads while maintaining positive pressure with your other hand to compress the baffle to the cup as you open and close?

Actually I tend to have the same problem for every type of headphone I get. :S
Probably the vibrations and movements during use make the screw threads get stuck or jammed, causing it's removal quite difficult.

 

[nick n]

make sure the screwdriver head is the exact fit for the shape if it's too large or too small it will slip around and wear off the screwhead edges.

 

[Nevod]

Haven't been there for a long time..
While last attempt at modding is doing fine, relatively, I don't think it's the end of all.
I've found some local rock wool/glass wool in at least moderately adequate quantities (1 sq m at 5 cm thickness), and want to try it out.
Plus I want to try out stuffing reticulated foam on the ear side of the driver, filling all the place between  ear and baffle. Perhaps that'd reduce reflections on the earside..

 

[preproman]

Quote:

Best DIY amp for these?

 
 
CK²III  M^3  βeta-22  All will work great.

 

[nrujac]

Hey all, great thread here. You guys have completely sold me on this undertaking, and I'm excited to get started. I bought materials to do the all rock-wool variant of the DBV3, so we'll see how it goes. The headphones are on backorder from front-end audio, yay.

Once I've had a chance to play with this though, and get my hands dirty modding, I kinda want to try my hand at constructing my own cups (wood). I was thinking of making open backed cups (protected with wire mesh), and seating the drivers in there (with proper dampening), and messing with it until neutral. But the thing is, I can't find any posts of anyone trying anything similar so I have no idea if what I'm going to end up with is a steaming pile of turd or a decent pair of headphones. I'm hoping to give these drivers a chance to really open up and show their stuff, but for all I know they're designed solely for closed/semi-closed cans, and sticking them in an open cup will screw everything up. The other option is to keep the cans closed, but cut in vents, similar to the stock cup.

So has anyone tried this? I've noticed that people are sealing their cups up (making them more closed) to raise the bass end of the FR spectrum up -- will I be taking it too far the other way? In a lot of ways, I won't know till I try, but it would be really cool to talk to someone who's attempted something even similar.

Thanks all. Man this is exciting.

 

[kalbee]

Hey all, great thread here. You guys have completely sold me on this undertaking, and I'm excited to get started. I bought materials to do the all rock-wool variant of the DBV3, so we'll see how it goes. The headphones are on backorder from front-end audio, yay.
Once I've had a chance to play with this though, and get my hands dirty modding, I kinda want to try my hand at constructing my own cups (wood). I was thinking of making open backed cups (protected with wire mesh), and seating the drivers in there (with proper dampening), and messing with it until neutral. But the thing is, I can't find any posts of anyone trying anything similar so I have no idea if what I'm going to end up with is a steaming pile of turd or a decent pair of headphones. I'm hoping to give these drivers a chance to really open up and show their stuff, but for all I know they're designed solely for closed/semi-closed cans, and sticking them in an open cup will screw everything up. The other option is to keep the cans closed, but cut in vents, similar to the stock cup.
So has anyone tried this? I've noticed that people are sealing their cups up (making them more closed) to raise the bass end of the FR spectrum up -- will I be taking it too far the other way? In a lot of ways, I won't know till I try, but it would be really cool to talk to someone who's attempted something even similar.
Thanks all. Man this is exciting.

Welcome aboard!
No, self-made open wooden cups haven't been undertaken very commonly around here since I guess a whole bunch of us, including myself, do not have access to all the tools and materials for it. Other reasons may include wanting to keep them closed for isolation.

Opening up the back of the cups will not necessarily kill the sound. The key is that with open and with closed design you will most likely need radically different damping schemes. A path most of us did not undertake (with the T50RP) but definitely not an impossible one. Your challenge would be the lack of information to serve as guideline. The other challenge is that you may need to make many irreversible mods in order to test things out.

I might still have some pictures of a semi-open ortho --> open ortho project I did. In my case, however, I reshelled the drivers completely... so difficulty level was at it's lowest, and luck level was pretty high.
Slowly but surely I am experimenting how to turn them into a closed back, using the same shells. Maybe that can help you out if you reverse engineer the process.

 

[FraGGleR]

I have access to a router at a community center and was going to find out if it can handle wood.  If it is, I am going to try to make some custom wood cups, although I will be keeping them closed/semi-closed to keep the bass response.  It will probably be a while til I can try it out, but will definitely post here if I try.  I am still waiting for prices to hopefully drop back down to $75 again to get another pair.  Wonder if I can get just the driver and baffle from Fostex.

 

[bluemonkeyflyer]

Quote:

I have access to a router at a community center and was going to find out if it can handle wood.  If it is, I am going to try to make some custom wood cups, although I will be keeping them closed/semi-closed to keep the bass response.  It will probably be a while til I can try it out, but will definitely post here if I try.  I am still waiting for prices to hopefully drop back down to $75 again to get another pair.  Wonder if I can get just the driver and baffle from Fostex.

 
If memory serves, the price for One driver is $69.00....Yep, just checked. I got these prices from the USA Fostex Distributor last year. The prices have not gone up!  LOL
 
Dust Cover (Ref. No. 10 on Exploded Diagram)
 Replacement Part Number:  1416902500
Sugg Retail: 4.95$ each side
No stock - ETA 3 to 4 weeks approx
 
Driver Gasket (Ref. No. 13 on Exploded Diagram)
Replacement Part Number:  1416902800
Sugg Retail: 7.49$ ea
No stock - ETA 3 to 4 weeks approx
 
Headphone Capsule (Driver Assembly; No. 15 on Exploded Diagram)  This is the driver.
Replacement Part Number:  1471300500
Sugg Retail: 69.95$ ea
No stock - ETA 3 to 4 weeks approx
 
Tiny Screws (Ref. No 23 on Exploded Diagram)
Replacement Part Number: 0514002200
Sugg Retail: 1.50$ each one!
 
 

 

[FraGGleR]

Quote:

 
If memory serves, the price for One driver is $69.00....Yep, just checked. I got these prices from the USA Fostex Distributor last year. The prices have not gone up!  LOL
 
Dust Cover (Ref. No. 10 on Exploded Diagram)
 Replacement Part Number:  1416902500
Sugg Retail: 4.95$ each side
No stock - ETA 3 to 4 weeks approx
 
Driver Gasket (Ref. No. 13 on Exploded Diagram)
Replacement Part Number:  1416902800
Sugg Retail: 7.49$ ea
No stock - ETA 3 to 4 weeks approx
 
Headphone Capsule (Driver Assembly; No. 15 on Exploded Diagram)  This is the driver.
Replacement Part Number:  1471300500
Sugg Retail: 69.95$ ea
No stock - ETA 3 to 4 weeks approx
 
Tiny Screws (Ref. No 23 on Exploded Diagram)
Replacement Part Number: 0514002200
Sugg Retail: 1.50$ each one!
 
 
 

That is almost as much as the whole headset!  Nevermind, will wait til the price drops again.  

 

[nrujac]

Welcome aboard!
No, self-made open wooden cups haven't been undertaken very commonly around here since I guess a whole bunch of us, including myself, do not have access to all the tools and materials for it. Other reasons may include wanting to keep them closed for isolation.

I don't expect that it'll be that hard. Would it help if I put together a picture tutorial on how to do it with easily available tools? It helps to have fancy equipment, but honestly, with enough patience you can do it with just hand tools you can pick up for a few bucks at . The key is really patience.

Opening up the back of the cups will not necessarily kill the sound. The key is that with open and with closed design you will most likely need radically different damping schemes. A path most of us did not undertake (with the T50RP) but definitely not an impossible one. Your challenge would be the lack of information to serve as guideline. The other challenge is that you may need to make many irreversible mods in order to test things out.

I'll have to do some research then, I'm totally clueless on acoustic design. Anyone know of any good resources on the subject? They don't have to be totally related, just enough that I can start understanding the theory behind it.

I might still have some pictures of a semi-open ortho --> open ortho project I did. In my case, however, I reshelled the drivers completely... so difficulty level was at it's lowest, and luck level was pretty high.
Slowly but surely I am experimenting how to turn them into a closed back, using the same shells. Maybe that can help you out if you reverse engineer the process.

I would appreciate any insight you can provide at all.

This is definitely a "down the road" sort of project. I intend to make and enjoy the DBV #3 first!

 

[kalbee]

I don't expect that it'll be that hard. Would it help if I put together a picture tutorial on how to do it with easily available tools? It helps to have fancy equipment, but honestly, with enough patience you can do it with just hand tools you can pick up for a few bucks at . The key is really patience.
I'll have to do some research then, I'm totally clueless on acoustic design. Anyone know of any good resources on the subject? They don't have to be totally related, just enough that I can start understanding the theory behind it.
I would appreciate any insight you can provide at all.
This is definitely a "down the road" sort of project. I intend to make and enjoy the DBV #3 first!

Any form of tutorial that can be added to the thread is always appreciated!
The key is indeed patience. I did my driver transplant and tested the damping by trial and error. If you're making your own cups, you may want to make it have easy access to the back of the driver without the removal of the cups. IMHO open-back is much easier to work with since there's a lot less reflection problems to address. And how a lack of treble doesn't really faze me... that's not for the better though.

 

[onefatsurfer]

I find that the sound quality is considerably better if I press the cups against my head.  Not sure if that is because of decreasing the volume of air, or because the drivers are closer to my ears, or because I'm not getting a good seal.. Anyone else notice this?

 

[bluemonkeyflyer]

Full Compass just increased the price for T20/40/50RP parts. Connector B is now Double the price from less than one week ago at $9.69 Each! The super glue fix I posted a few days looks a lot more attractive, now.

 

[FraGGleR]

Current setup:
 
Baffle flush filled with plasticine
Acoustic foam and felt in cups (no pyramids yet)
J$ Beyerdynamic pads
Stiff felt transpore taped to back of driver with large holes (normal hole punch)
Baffle ports are temporarily sealed with hot glue
Roughly half an inch of Rite Aid rolled cotton
 
I was silly and did two mods at once so I cannot tell which one changed my sound.  I switched from unrolled cotton balls to the Rite Aid cotton and sealed the baffle ports with hot glue.  I didn't notice too much of a difference in treble (maybe slightly smoother), but my bass volume dropped noticeably.  I think the cotton I used was roughly equivalent to what I had in there, and sealing the ports was supposed to increase bass.  Regardless, I want to understand how bass works a little better.  I have been trying mods because others have said the do X or Y and to a point, that has been fine.  But does anyone have resources about enclosure acoustics that I could read up on?  Later down the road, custom cups are something I'd like to attempt, but I need to understand more.  Maybe just a better summary of why each mod does what it does (not just increase or decrease treble, but why it does that, ie what do the pyramids do?)
 
Anyone have any favorite resources that can share?  Thanks guys, this is really fun.