[ZGLISZCZ]

   
I'm about 90% sure it's not the driver at this point, as it's been coming and going so much - I imagine if it was the driver it'd be a constant thing. Also, I read one of your other posts where I think you said that the alpha pads sacrificed some quality for comfort? As in, the 840 pads had better sound quality? One more thing, have you looked into any of this "knurling" stuff, the stuff Mr. Speakers did for the Alpha Prime: https://mrspeakers.com/alpha-prime-headphones/ . I imagine it might be hard to do for multiple headphones in an assembly line, but maybe for us only focused on one headphone, it'd be doable. Apparently it improves the sound a lot, but that could just be hype, I don't know. Something is different about the Alpha Primes, and this seems to be it - 

If you will take look at the diaphragm you will see that lines goes straight, then zigzag, then straight, then zigzag... I believe Mr. Speakers folded diaphragm in those places, maybe on zigzag maybe on straight lines maybe between. you will need to look at it and the magnets. Im sure that was beginning of his idea. You will need to check it by yourself.

 

[lawrecedent]

maul,

If you (or anyone) need to replace a faulty diaphragm, I have a spare. As nick n mentioned, once in a while there is warped diaphragm that gets past Fostex QC and  hits the magnets, causing a bass rattle or hum. This problem may be addressed in FIMM...I don't remember for sure.

As long as the dust cover on the ear side and the white "paper" on the rear side of the driver are intact, you don't need to worry about debris inside the driver.

~ BMF

Check it's not a cable, I had a similar problem with some Beyerdynamic dt770 where I was dismantling the drivers looking for a hair or dirt etc and it turned out to be the wire connecting the driver. I taped it down and had no problems since. Might be worth a look.

 

[edges7z]

Hey complete noob question here. Just got a set of these and I'm wondering what people do with the two wires coming out of the cups into the headbands? They don't bother me but aesthetically/safety worries me. I put in/take these out of a QotSA military breadbag (rough cloth) and take them to work every day and I always worry too much pushing pulling dragging etc on the wires will damage or pull them. Any word? Thanks

 

[bluemonkeyflyer]

Hey complete noob question here. Just got a set of these and I'm wondering what people do with the two wires coming out of the cups into the headbands? They don't bother me but aesthetically/safety worries me. I put in/take these out of a QotSA military breadbag (rough cloth) and take them to work every day and I always worry too much pushing pulling dragging etc on the wires will damage or pull them. Any word? Thanks

Re-cable them, dual entry...can be balanced or unbalanced...and make the cables detachable.
 
Search this thread, and others, for "How to."
 
There are guys that offer this service who post in this thread and the the Wow T50RP thread. PETEREK (formerly cCasper TFG) does beautiful re-cabling and custom painting.

 

[nick n]

Agree with BMF great suggestion on dual entry = PETEREK does excellent classy work from what I have seen.

 

[walbum4262]

Hey complete noob question here. Just got a set of these and I'm wondering what people do with the two wires coming out of the cups into the headbands? They don't bother me but aesthetically/safety worries me. I put in/take these out of a QotSA military breadbag (rough cloth) and take them to work every day and I always worry too much pushing pulling dragging etc on the wires will damage or pull them. Any word? Thanks

A few pages back
http://www.head-fi.org/t/618659/fostex-t50rp-incremental-mods-and-measurements/1920

I have a build log showing how to install mini xlr plugs into the cup if you have the skills to try and do it yourself

 

[maul]

Alright I'll make a small contribution here as this thread has helped me greatly. After about 30 documented variations I've devised a mod that I think (maybe) I'll be sticking with for awhile. I have a 400i with neutral-like bass, so I've been striving for a planar with more bass impact... but at the same time upping the clarity, but at the same time reducing any harshness – heh.

I've had a few other variations where I've achieved a good balance, like with porous coffee filters as one example (square coffee filter over penny-sized coffee filter reflector):



This one requires there to be some insulation on the non-driver side to tighten things up. I have another really good one I'll probably post here at some point, but I don't have pictures right now. I think my current one is the best so far, so I'll just give a quick recap of some of it...

The non-driver side has the BMF stuff like the ladder structure (now pretty flattened btw) etc. with a layer of cotton above it: 



I had a layer of insulation over it, and it certainly tightens things up, but as I'm going for more bass impact I ended up removing it. As I said before I've been wanting high clarity/strong bass/low harshness, and it's been a particularly difficult balancing act. Without anything on the driver everything seems muddy but the bass is strong, and if you put on too many things it can become harsh with lessened bass.
 
I've tried doing various bass holes but most of the time their positions are a little random over the driver, making the sound somewhat uneven to my ears. So I came up with what I think to be a decent solution:
 

 
In each of the square driver areas, half of the sound is reflected back for more treble, half is let through for more bass. Pretty simple:
 

 
I find though, at least with the insulation removed, that the front/back of a magazine is the best material to use:
 

 
Use some tracing paper to get the layout, tape two magazine pieces together to do two at once, transfer the lines and use a razor blade to cut everything out. Double-sided tape with removable backing to put them on. Regular paper lets more sound through for a lighter sound, magazine paper gives a stronger sound/more clarity.
 
I found that covering up the entire middle driver area makes things a bit sibilant, so with this half and half structure everything seems to be more balanced. It's given me the best of both worlds with strong bass and clear (but not sibilant) highs and mids. The vents are open, and the bass ports are currently closed. I'll be messing around with opening them/putting a small pinprick in the tape, etc. later. Usually opening the bass port tighten things up a bit/reduces the bass very slightly, but it won't have a big impact either way. 
 
So yeah, this is my best mod currently. Should have a kit soon to see how it measures. I would suggest adding insulation over the cotton if you want tighter bass - 

 

[bluemonkeyflyer]

  Alright I'll make a small contribution here as this thread has helped me greatly. After about 30 documented variations I've devised a mod that I think (maybe) I'll be sticking with for awhile. I have a 400i with neutral-like bass, so I've been striving for a planar with more bass impact... but at the same time upping the clarity, but at the same time reducing any harshness – heh.

I've had a few other variations where I've achieved a good balance, like with porous coffee filters as one example (square coffee filter over penny-sized coffee filter reflector):

This one requires there to be some insulation on the non-driver side to tighten things up. I have another really good one I'll probably post here at some point, but I don't have pictures right now. I think my current one is the best so far, so I'll just give a quick recap of some of it...

The non-driver side has the BMF stuff like the ladder structure (now pretty flattened btw) etc. with a layer of cotton above it: 

I had a layer of insulation over it, and it certainly tightens things up, but as I'm going for more bass impact I ended up removing it. As I said before I've been wanting high clarity/strong bass/low harshness, and it's been a particularly difficult balancing act. Without anything on the driver everything seems muddy but the bass is strong, and if you put on too many things it can become harsh with lessened bass.

I've tried doing various bass holes but most of the time their positions are a little random over the driver, making the sound somewhat uneven to my ears. So I came up with what I think to be a decent solution:
 
In each of the square driver areas, half of the sound is reflected back for more treble, half is let through for more bass. Pretty simple:
 
I find though, at least with the insulation removed, that the front/back of a magazine is the best material to use:
 
Use some tracing paper to get the layout, tape two magazine pieces together to do two at once, transfer the lines and use a razor blade to cut everything out. Double-sided tape with removable backing to put them on. Regular paper lets more sound through for a lighter sound, magazine paper gives a stronger sound/more clarity.
 
I found that covering up the entire middle driver area makes things a bit sibilant, so with this half and half structure everything seems to be more balanced. It's given me the best of both worlds with strong bass and clear (but not sibilant) highs and mids. The vents are open, and the bass ports are currently closed. I'll be messing around with opening them/putting a small pinprick in the tape, etc. later. Usually opening the bass port tighten things up a bit/reduces the bass very slightly, but it won't have a big impact either way. 
 
So yeah, this is my best mod currently. Should have a kit soon to see how it measures. I would suggest adding insulation over the cotton if you want tighter bass - 

 
 
Hey maul,
 
Great to see some new mods! Thanks for sharing. Your mod configuration and hypotheses are very interesting.
 
A question: Define "vents are open" and "the bass ports are currently closed."
Are you referring to the single, small round hole at about 1 o'clock on the ear side as the vent?
Are the 4 bottom vents in the cups with stock felt over them on the inside as the bass ports?
...Or....?
 
When you get your measurement kit you can make some objective measurement comparisons. It would be interesting to see your REW FR graphs, Spectrograms, and Waterfalls; and/or your ARTA CSDs, FR graphs, and THD. To control for expectation bias, you could describe your hearing impressions Before measuring and then post your impressions along with your measurements for:
1. "All Stock" T50RP vs
2. "maul's mod" T50RP vs
3. any other fully stock headphone you have on hand. 
 
I recommend downloading REW and ARTA (both free but please make a donation to REW) and my REW raw data files for FIMM (in Post 1) and start to familiarize yourself with the measurement software.Same for ARTA. In Post 1, I provided links to pictorials for setting up and using REW and ARTA.
 
Please post your questions, here, and I'll answer what I know. hans and a few other guys with measurement experience may chime in with additional help. This may help many others benefit and get the measurement bug. 
 
EDIT
Just a thought about your rattle and hum that comes and goes. It may be the magazine paper vibrating against the back of the driver. Make sure it's glued down, completely. Rubber cement may work best for easier removal in case you want to try something different. Also, to avoid unintended consequences, be sure no glue gets on the white paper that overlays all 9 grid openings. If this happens, the SQ and FR will be altered...and likely not reversible.

 

[maul]

   
 
Hey maul,
 
Great to see some new mods! Thanks for sharing. Your mod configuration and hypotheses are very interesting.
 
A question: Define "vents are open" and "the bass ports are currently closed."
Are you referring the single, small round hole at about 1 o'clock on the ear side as the vent?
Are the 4 bottom vents in the cups with stock felt over them on the inside as the bass ports?
...Or....?
 
When you get your measurement kit you can make some objective measurement comparisons. It would be interesting to see your REW FR graphs, Spectrograms, and Waterfalls; and/or your ARTA CSDs, FR graphs, and THD. To control for expectation bias, you could describe your hearing impressions Before measuring and then post your impressions along with your measurements for:
1. "All Stock" T50RP vs
2. "maul's mod" T50RP vs
3. any other fully stock headphone you have on hand. 
 
I recommend downloading REW and ARTA (both free but please make a donation to REW) and my REW raw data files for FIMM (in Post 1) and start to familiarize yourself with the measurement software.Same for ARTA. In Post 1, I provided links to pictorials for setting up and using REW and ARTA.
 
Please post your questions, here, and I'll answer what I know. hans and a few other guys with measurement experience may chime in with additional help. This way help many others may benefit and get the measurement bug. 
 
EDIT
Just a thought about your rattle and hum that comes and goes. It may be the magazine paper vibrating against the back of the driver. Make sure it's glued down, completely. Rubber cement may work best for easier removal in case you want to try something different. Also, to avoid unintended consequences, be sure no glue gets on the white paper that overlays all 9 grid openings. If this happens, the SQ and FR will be altered...and likely not reversible.

 
When I talk about vents I mean the 4 in the cups, everything is stock there. I've tried a lot of things with them but I prefer them unmodified for the sound signature I'm going for. I believe in your DBV #3 you also have them unmodified. Yeah, by bass port I mean the one hole on the ear side - just covered up with some tape currently. Edit: Maybe I should say baffle port or something, I don't remember the correct phrase.
 
I don't have a stock T50RP so I imagine I'd have to use your measurements as a comparison? I know that's not ideal, but I can definitely do a couple other headphone measurements. I'll certainly start looking into the software, shame I didn't have it when I was doing all my other tests, but what can you do. I've narrowed ~30 variations down to about 3 that I prefer so I'll probably end up measuring those. 
 
The thing about the rattle is that it has been present for variations that didn't include the magazine paper. I did a variation with nothing on the driver a couple days ago and my notes don't mention a bass rattle so it may have something to do with it - could just be random chance though. I usually use 4 thin strips of double sided tape to place things on the driver, so it's pretty solid. The coffee filter variation was really solid and the damn rattle cropped up even then. It usually goes away when I rotate the cup which changes the position of the wire, but that might just be coincidence. I WILL find the source one of these days, heh. Right now it's not doing it, so I'm happy. Thanks for the tip, I probably won't be using any glue for awhile as I make so many variations and tape is quick, but this one will stay for awhile, that's for sure - 

 

[maul]

I tried to glue the HD 600 headband on, but the glue I used wouldn't stick to the rubber, and made a mess of the headband. Also, with the stretching of the headband, it just seemed like getting glue to work properly was going to be a pain. Either way I was sick of dealing with glue. So I wrapped some rubberbands between the 3 gaps and put this over it:
 

 
Not the prettiest thing in the world but I like it, and you can still see the HD 600 headband grooves. It is a bit heavy. I'm still satisfied with that mod btw, although I ended up re-adding the insulation as well as a square piece of regular felt over the magazine paper. Didn't reduce the bass very much and everything is much tighter & clean sounding. Next step is probably modding the connectors and eventually a paint job. Yesssss

 

[bluemonkeyflyer]

  I tried to glue the HD 600 headband on, but the glue I used wouldn't stick to the rubber, and made a mess of the headband. Also, with the stretching of the headband, it just seemed like getting glue to work properly was going to be a pain. Either way I was sick of dealing with glue. So I wrapped some rubberbands between the 3 gaps and put this over it:
 

 
Not the prettiest thing in the world but I like it, and you can still see the HD 600 headband grooves. It is a bit heavy. I'm still satisfied with that mod btw, although I ended up re-adding the insulation as well as a square piece of regular felt over the magazine paper. Didn't reduce the bass very much and everything is much tighter & clean sounding. Next step is probably modding the connectors and eventually a paint job. Yesssss

 
It's difficult to get glue to stick to the stock rubber headband, for sure!
 
I installed an HD-600 headband cushion on a set. The best I've been able to achieve is by using high viscosity super glue plus super glue accelerant. Other brands probably work just as well. You just have to accurate when joining them And fast because the bond is Instant...so, no easy adjustment if you get off center.
 
Good luck.

 

[bluemonkeyflyer]

   
When I talk about vents I mean the 4 in the cups, everything is stock there. I've tried a lot of things with them but I prefer them unmodified for the sound signature I'm going for. I believe in your DBV #3 you also have them unmodified. Yeah, by bass port I mean the one hole on the ear side - just covered up with some tape currently. Edit: Maybe I should say baffle port or something, I don't remember the correct phrase.
 
Comment:
There are performance and sound quality differences from one production run to the next. For some T50/40/20 RP headphone mods, I leave the cup vents open but in others a "Better Modified Bass Port works best. Of course with the T40RP, I remove the plastic cover from the inside of the cup vents and install a felt square in its place; then, leave alone or make a Bass Port, if needed to tighten up the bass.
 
I don't have a stock T50RP so I imagine I'd have to use your measurements as a comparison? I know that's not ideal, but I can definitely do a couple other headphone measurements. I'll certainly start looking into the software, shame I didn't have it when I was doing all my other tests, but what can you do. I've narrowed ~30 variations down to about 3 that I prefer so I'll probably end up measuring those. 
 
Comment:
You cannot reliably compare your measurements with mine or anyone else's even if you duplicate the measurement chain and method. That's why I always say you can only reliably compare your measurements to your own. Even then, the comparisons should be within the same measurement cycle.
 
The thing about the rattle is that it has been present for variations that didn't include the magazine paper. I did a variation with nothing on the driver a couple days ago and my notes don't mention a bass rattle so it may have something to do with it - could just be random chance though. I usually use 4 thin strips of double sided tape to place things on the driver, so it's pretty solid. The coffee filter variation was really solid and the damn rattle cropped up even then. It usually goes away when I rotate the cup which changes the position of the wire, but that might just be coincidence. I WILL find the source one of these days, heh. Right now it's not doing it, so I'm happy. Thanks for the tip, I probably won't be using any glue for awhile as I make so many variations and tape is quick, but this one will stay for awhile, that's for sure - 
 
Comment:
I like double sided tape better than glue, too. I'm glad to hear the rattle is gone. 
~BMF

 

[backdoorcdrs]

Just got a pair of these about a week ago and have started modding them. So far, I am very impressed. However, I still have a feeling that they can be improved with some of the slight grain/distortion and sibilant sound. They already sound better than most of my headphones that cost 3-4 times as much. Not sure how realistic it is to expect to improve them even more, but I have a couple questions to see what some of you guys that have more experience with them think.
 
What I have done so far:
* loaded the baffles with modeling clay
* put dynamat in the cups
* put adhesive felt over the dynamat (used what I had on hand)
* sealed the cup vents
* experimented with cotton and foam filling the cups, decided I like them better with none
* Felt with 4 holes in the corners punched out over the rear of the driver
* dynamat and felt over the ear side of the baffle
* 2 pieces of felt over the ear side of the driver to reduce sibilant sound
* I'm using SRH840 pads
 
Do you think that using the silverstone acoustic foam in the ladder shape instead of adhesive felt over the dynamat in the cups will help with the small amount of grain/distortion? Any other ideas that might help with the sibilance? The felt on the driver side helped a lot so far.
 
Thanks in advance for any help or suggestions.

 

[SeEnCreaTive]

Just got a pair of these about a week ago and have started modding them. So far, I am very impressed. However, I still have a feeling that they can be improved with some of the slight grain/distortion and sibilant sound. They already sound better than most of my headphones that cost 3-4 times as much. Not sure how realistic it is to expect to improve them even more, but I have a couple questions to see what some of you guys that have more experience with them think.

What I have done so far:
* loaded the baffles with modeling clay
* put dynamat in the cups
* put adhesive felt over the dynamat (used what I had on hand)
* sealed the cup vents
* experimented with cotton and foam filling the cups, decided I like them better with none
* Felt with 4 holes in the corners punched out over the rear of the driver
* dynamat and felt over the ear side of the baffle
* 2 pieces of felt over the ear side of the driver to reduce sibilant sound
* I'm using SRH840 pads

Do you think that using the silverstone acoustic foam in the ladder shape instead of adhesive felt over the dynamat in the cups will help with the small amount of grain/distortion? Any other ideas that might help with the sibilance? The felt on the driver side helped a lot so far.

Thanks in advance for any help or suggestions.

Dynamat, Silverstone foam, and other sound proofing things, all they do is stop reflections coming off the inside of the cup back to the ear.

Some argue that the ladder shape will help break up echoes. Something like why studio foam boards are egg carton or triangles.


I'm not sure about distortion, but to my understanding 99% of these mods done, only enable the driver to sound as best it can. Ie: stopping echoes, damping the air so it doesn't go out of control. But a t50rp driver sounds like a t50rp driver. I'm guessing things like distortion are flaws with a cheap orthro. There isn't really a magic peice of felt you can stick on to reduce distortion

Again I'm guessing at this point, I'm don't know enough to say that is correct or not. BMF might be the guy to ask with all his experience with measurements.

 

[c61746961]

There's just one way to 'lower' distortion, which is to mod while keeping the efficiency of the driver as high as possible, that is, make the driver work less for the same output (very good seal on the pads, more driver damping, perhaps a lower cup volume).