Fostex T50RP Incremental Mods and Measurements
Nov 10, 2017 at 3:20 AM Post #2,386 of 2,832
Opened the driver all well, putting it back the glue sticking the magnets in place had dried up and couldn't hold them in place and as I put the assembly together they came off and stuck to the membrane hard. Putting a hole in the membrane.

IMG_20171110_131443.jpg

IMG_20171110_131514.jpg


I guess this is the end of modding journey.
 
Nov 10, 2017 at 6:50 PM Post #2,388 of 2,832
Opened the driver all well, putting it back the glue sticking the magnets in place had dried up and couldn't hold them in place and as I put the assembly together they came off and stuck to the membrane hard. Putting a hole in the membrane.

IMG_20171110_131443.jpg

IMG_20171110_131514.jpg


I guess this is the end of modding journey.

Fostex will probably sell you a replacement driver.
 
Nov 10, 2017 at 7:06 PM Post #2,389 of 2,832
I have a pair of T40RP MK2's that I've stripped the drivers out of. Literally everything else is there, screws and all, still in one piece. I might also have a pair of MK3's that I'm stripping, but we'll see how much I keep after assembling my Open Alpha Dogs.

If anyone wants to snatch the Mk2's from me, gimme a PM and we'll talk :)
 
Nov 10, 2017 at 7:09 PM Post #2,390 of 2,832
Ooh that sucks
May I ask how you managed to do that? did you bend the drivers or something?
That really is unfortunate.

I've almost experienced a similar situation. I'm guessing the magnets slammed down because they were attracted to eachother. I almost killed my DT770 driver because I was tweezing off a couple hairs from the diaphragm, and forgot to hold it down. Magnet sucked the whole driver up into my tweezer, and the tweezer was jabbed into the diaphragm. Luckily the diaphragm only got a small white dent, and worked fine, with no audible differences :p
 
Nov 10, 2017 at 7:28 PM Post #2,392 of 2,832
I've almost experienced a similar situation. I'm guessing the magnets slammed down because they were attracted to eachother. I almost killed my DT770 driver because I was tweezing off a couple hairs from the diaphragm, and forgot to hold it down. Magnet sucked the whole driver up into my tweezer, and the tweezer was jabbed into the diaphragm. Luckily the diaphragm only got a small white dent, and worked fine, with no audible differences :p

Lucky it wasn't the 1770 with the tesla drivers. Recabling my 1350's shocked hell out of me when that damn magnet decided it wanted to try to pull the soldering iron onto itself without warning.
 
Nov 11, 2017 at 7:45 PM Post #2,393 of 2,832
Hey all,

I've been following this thread for a while and but I just now decided to join the forum. Currently I'm running T50RP MK3s with the Shure 1540 pads, Newplast baffle damping, and a balanced cable mod.

So I'm curious if anyone has tried making custom driver frames. Ive been thinking of machining a set of new frames out of some more ridged material. Does anyone think it would be worth it? Are there any odd things about the design that I might need to take into consideration? Ive talked to one of the professors at my school who specializes in electromagnetism about material choices. He said that using a material like aluminum for the frame could cause eddie currents to form within the aluminum because of the movement of the EM field produced by the movement of the driver which would increase the force it takes to move the driver. Could that be taken advantage of or is it just a negative?

Thanks
 
Nov 18, 2017 at 6:05 PM Post #2,394 of 2,832
Mr Speaker has released his Alpha dogs, which can be found on the thread
https://www.head-fi.org/threads/open-alpha-t50-3d-printed-headphone-project-from-mrspeakers.825868/

You can get the dimensions for the baffle from the parts, which from what I've heard was used to make the Mad Dogs (Pros?)
And then you can base your measurements for driver, screws, cups from those.

There's a few parts on thingiverse, but I don't think they'll really help in designing new parts.
Other than that, I don't think there's much else.
Thank you very much, the thread is very useful!
 
Nov 24, 2017 at 5:52 PM Post #2,395 of 2,832
I'd love to share one of the most efficient T20RPmk2 mods I've ever done. I got the idea from observing various AKG headphone internals. You probably know those funny headphones with huge headstage and lots of internal reflections:
IMG_1020.JPG
This little plastic ring brings in loads of upper mids. So much I even started to experience a lack of bass (I'm currently using angled protein leather Brainwavz pads and only a moderate amount of Omnipor behind the drivers). I'm using virtually no stuffing, just don't feel like I need any.
 
Nov 30, 2017 at 1:53 AM Post #2,396 of 2,832
The resonant ring boosts a narrow band around (340/diameter/2) Hz (speed and sizes all metric). It won't look good at CSD plots but it will sound good to human ear. I was referring to Tyll Hertsens' target curve that's peaking sharply at 3.5 kHz. A ring with inner diameter of 49mm is a good place to start for an average head size (57 cm circumfrence). A rule of thumb would be to change the size (and resonant frequency) by 1% at each cm. I.E.: my head circumference is 62 cm, 5 cm larger than average, so I'd better use a larger ring, about 51 cm. (btw, that's the diameter of a Grado cup)
The ring pictured above is about 46mm, that woud better suit a child head. It sounded too harsh to me (shifting the peak higher sounds like boosting lower treble). The ring I'm using now is about 53mm in diameter. A little too large for me but sounds really good, just a tad warm, with enough definition and no treble harshness at all.
 
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Dec 22, 2017 at 3:21 PM Post #2,397 of 2,832
i changed the pads to my fostex t50rp mkii mayflower v3 mod with those bigger pads
the sound is greatly improved, they have more treble than before (the v3 mayflower mod is dark and bassy) and the soundstage is bigger to already big soundstage with the normal pads
actually the soundstage is so big that i was shocked at first, bigger than sennheiser hd600 and 650, at the same time they have black background and the imaging is precise, spectacular headphones maybe the best value under 300 dollars price tag for closed backs ever, i got mine for 140 dollars second hand in perfect condition and the pads are around 40 dollars, better than oppo pm3 for sure
10043683.jpg
 
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Dec 29, 2017 at 12:05 PM Post #2,398 of 2,832
Hi!

Zeos fooled me and I bought a pair of T50RP Mk3 with 1540 pads. It sound fun, but there was too much and unbalanced bass, too much highs around 10k and theere was dips in the mids. I put 1-1g cotton in the cups and now it's pretty good. The bass are there but not overwhelming and the highs are not sharp anymore.
I don't have a rig, but there are dips at 1,4k 7k, 10k and a drop under 40hz and peaks around 0,7k 3,6k and at 9k.
Can I bring back up 7k and around 1,4k with a little more bass (especially low end)?
 
Dec 30, 2017 at 8:53 AM Post #2,399 of 2,832
Hi!

Zeos fooled me and I bought a pair of T50RP Mk3 with 1540 pads. It sound fun, but there was too much and unbalanced bass, too much highs around 10k and theere was dips in the mids. I put 1-1g cotton in the cups and now it's pretty good. The bass are there but not overwhelming and the highs are not sharp anymore.
I don't have a rig, but there are dips at 1,4k 7k, 10k and a drop under 40hz and peaks around 0,7k 3,6k and at 9k.
Can I bring back up 7k and around 1,4k with a little more bass (especially low end)?
I boosted the bass, by covering 3 baffle vents and I got a pretty good sound, I love it. I recommend this easy mod for those who also have an MK3 and a par of 1540 pads and want to change. (If the bass is too much, just uncover some, if the bass is not enough with 3 covered, cover more).
I like this sound, much more detailed than the stock mk3 + 1540. The sound stage is also bigger and the imaging is awesome. (In my opinion)
 
Jan 23, 2018 at 9:35 AM Post #2,400 of 2,832
Hey all, I'm having a minor issue and figured this was the thread to ask. I custom made a comfort strap for my T50Rp's. As you know, the comfort straps fasten with 2 screws, 1 screw per side. Currently, 1 screw will slowly loosen up a bit. If I don't re-tighten, it will eventually cause the assembly to fall apart. Has anyone tried using some blue Loctite on this screw? I suppose it would come down to whether loctite is compatible with plastic? Edit: just looked it up and not recommended for plastic. other ideas to achieve end result?

While I'm aware of this issue, my wife will forget & I don't want them to fall apart on her.
 
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