Just listened to some Fostex T50RPs today... WOW! - Page 98

I  just soldered up a mini-cable for my T-50RP's I shaved an ~80 degree L plug down to fit in the recessed jack (really nicely, I may add) and liberated a cable from some sansa earbuds. The cable is definitely lower quality than the stock one (I wrapped pieces of plastic over the solder joints, then put a piece of heatshrink over it one both the connections, so I wouldn't short the channels to each other or ground) but they sound close enough the same that I won't worry about it. I had to shrink the heatshrink with my soldering iron, slowly and carefully waving it under the cable. I'll hit it with a blowdryer once I can convince a girl to let me borrow one.

I still haven't taken mine apart, but they are quite robust to be shoved in my backpack thrice daily.

Excellent headphone for portable use. I'll have to do some A/B with my SR-225i to see which I prefer, but thus far I'm really happy with these.

Good luck with your dampings, everyone!

Quote:

Originally Posted by tdockweiler 

I think I must have the world's worst T50RP! I got the Akasa foam in today and took my time on starting over from scratch.

 

First I removed all my Blu-tack except what was on the baffle. I made sure every single area was covered with the foam except for the vent. When this was done, it sounded just as bad as when I used Blu-Tack and lighter foam.

100% zero change. I then just did a small test and added an old piece of foam to the cups. It's just two small cutouts from a piece of foam. The type found in a pillow kind of. This made the mids a lot more forward and it really got to my ears and annoyed me. Too forward!

The sound was VERY muffled though, but less cave-like. I removed the foam pieces and kept the original Akasa in there. Next I just out a large square piece of Akasa foam and placed it in there. The sound was even more clear and the mids were even better. How the heck does that happen?!

 

So the sound was slightly better and even seemed to improve when I put some ultra thin foam under the earpads (not the Akasa obviously). However it's possible, it even helped the clarity a bit.

 

Right now overall they sound not very good at all. Not sure why. They do many things right, but the sound still is kind of muffled and not too clear. Nothing horrible. I hate my Sextett, but these at the moment feel like a half-a**ed version of that. It's really frustrating that I spent all that time and gotten nowhere. I'll figure out some things and go from there. I do know that if I keep the vents open the bass is very excessive. Right now I have it covered with a piece of foam temporarily. I don't think it's over-dampened. When I had less in there, everything sounded so distant and muffled.

 

Next thing I might do is replace the blu-tack with that modeling clay stuff. The highs right now are EXTREMELY rolled off. Cymbals are..gone? It just feels like the whole signature is completely missing something. Ugh, everything feels kind of distant and not in a good way. Still not horrible. Right now it just feels like a slightly above average $70 headphone.

 

I'll check all the old threads and see if I can come up with something. Maybe dampening the driver itself with different materials will help. I tried it with some felt, but that probably was too thick and it killed the mids. I think the main issue I have is that level of clarity is low and the highs are VERY rolled off.

 

I'll keep trying.

taking the felt off of the front of the driver makes a tremendous difference in clarity and treble, also changing the pads makes a huge difference, I would suggest the srh840 pads if you are cheap and dont mind pleather. Also maverickronin brings up some very good tips

I don't want to make any promises, since I haven't tried them, but I know some of the older AKG ones do stretch over nicely (though I don't like how they sound).

I definitely agree with that, but I'd suggest to people that try that, to make sure it's replaced with something else.
I cut away the felt on the first day and I've always had the baffle dampened with blu-tack. I may replace that with plasticine though. I didn't fill in the extremely tiny holes closer to the driver though. In most pictures I've rarely seen people do this.

I'm also wondering if it's worth it to put foam right up to the VERY EDGE in the cups. I think there might be no point and it would be harder to screw everything together. I also might add more Akasa back to the inner edges of the cup. I removed them and the sound didn't change much.

Quote:

Originally Posted by turimbar1 

taking the felt off of the front of the driver makes a tremendous difference in clarity and treble, also changing the pads makes a huge difference, I would suggest the srh840 pads if you are cheap and dont mind pleather. Also maverickronin brings up some very good tips

Quote:

Originally Posted by tdockweiler 

I definitely agree with that, but I'd suggest to people that try that, to make sure it's replaced with something else.
I cut away the felt on the first day and I've always had the baffle dampened with blu-tack. I may replace that with plasticine though. I didn't fill in the extremely tiny holes closer to the driver though. In most pictures I've rarely seen people do this.

 

I'm also wondering if it's worth it to put foam right up to the VERY EDGE in the cups. I think there might be no point and it would be harder to screw everything together. I also might add more Akasa back to the inner edges of the cup. I removed them and the sound didn't change much.

 

I encountered some of the same issues and while my phones still need a bit of EQ they are pretty good now. I used modeling clay to fill in the baffles and a layer of akasa foam in the cups (see picture). I have more akasa foam than most others and it might be too much, I'm not sure. I personally found that replacing the stock felt over the vents (which are open in the picture) helped a lot with the clarity of my phones and especially the highs. Other people like them open but try them both ways. I also found that removing the stock felt over the drivers on the ear-side of the cups helped with clarity but also creates some harsh mids that need to be tamed with felt, foam, or something else (Joel used suede) inside the ear cups to absorb stray reflections. I was using a layer of wool felt like LeePerry over the entire ear-side surface but I now have the driver uncovered like joel and mrspeakers (except for the thin mesh protective cover) but surrounded by akasa foam in the back and wool felt in the front (the foam in back also helps angle the pads). Not perfect but those few changes helped a lot with the muffled sound and lack of clarity in the highs that I encountered before. A lot of people have pointed out that once the baffles have been mass dampened to kill the resonances and a thin layer of acoustic dampening foam has been added to the inside cups to kill reflections, most of the fine tuning is done inside the earpads. 

plasticine has one of the best damping factors out there, and that will help keep the phones from vibrating and allow the driver to be more efficient, also it is super cheap. I got my modeling clay for $3.40, and I have more than enough. The foam in the edge of the cups is overkill imo, but I have not tried it, so I really could not say, I use plasticine around the edges personally. 

I really wish you could come to the SD meet so you could hear other modifications and make your decision based on that, it will definitely be a learning experience. Looking forward to it. 

Would the Beyer dt250 pads fit the T50RP?

And these looks good http://www.buzzillions.com/reviews/pearstone-deluxe-earpads-pair-reviews
 

Quote:

Originally Posted by joelpearce 

Yeah, I wouldn't recommend the Beyer pads that strongly, since you would essentially have to glue them on.  

Quote:

Originally Posted by ardilla 

Would the Beyer dt250 pads fit the T50RP?

 

And these looks good http://www.buzzillions.com/reviews/pearstone-deluxe-earpads-pair-reviews
 

 

No, the DT250 is quite small.
 

Ok, this is very strange. Today I about had it with these T50RPs. I felt the whole time I must have had a complete lemon. I don't even want to know how many hours I spent trying to mod them to get them to sound good.

Today I decided to give it one last try. I made sure every tiny area of the shell was covered in Akasa foam. Even to the outer edges. I left the vent open. I put everything back together and it sounded terrible...again. The main problem is that the sound was very muffled. Like the driver was covered with a thick fabric.

I opened it back up and covered the vent with Akasa foam. Tried again and the sound was now CLEAR!! I don't now why or how this could effect the sound clarity. It doesn't make sense.

Right now everything sounds maybe good, but I haven't listened to them long enough. I've tried various materials over the driver behind the earpad and the sound irritates my ears. The feeling is as if the mids are too forward, but it doesn't really sound like it.

I really don't know why, but these headphones have been the most ear fatiguing headphones I've ever owned. How could this be? I don't even keep the volume up super loud. On my first day my ears were ringing so bad, but yet the volume wasn't high. I was thinking it was a combinations of too much use of headphones and allergies at the time.

I guess i'll try more materials over the earpad and see if I can make some changes.

Right now my pair sounds about as good as a $120 headphone

I still think my pair is just not a very good one.

(baffle is dampened with blu-tack. Still need to try the modeling clay)

Quote:

Originally Posted by tdockweiler 

One thing you might want to try is removing the foam over the vent. It's easy to reverse. It made a HUGE difference in the sound for me. After that also try removing those two tiny pieces of felt below the vent. This seemed to change the sound for me and improve the highs. On mine I cut off the felt under the earpads exposing the driver itself. There's still a piece of fabric there to keep it closed off though. Using cabinet liner with holes in it worked really well for me under the earpads. It may be hard for some to believe!

Thanks yeah I might try that next... while the resonance is gone and the sound is forward I'm not completely satisfied with it. There's hardly any bass and male voices in particular sound very muffled and hold no weight.

After maybe a dozen or more hours I finally got my garbage T50RP to sound quite good. Not really all that impressive, but very good in some areas like vocals.

I thought this post might be helpful who couldn't get any good results no matter what they tried. This works for me and I doubt anyone has a similar configuration.

1) Add blu-tack to baffle

2) Remove felt under earpad (suggest trying the results first with it still on)

3) Add Akasa foam inside cup. Only 1 layer. I did this on EVERY single exposed piece of plastic. Don't use two layers. Right up to the edges!

This is where it got tricky for me. With the vent open with all this foam it ruined the sound completely. It made the sound extremely muffled and distant. This is before I did ANY other modifications past this point!!

4) Added a piece of felt to the back of the ENTIRE driver. Sounds crazy, I know! Micropore/Transpore does absolutely squat for me.

I tested this out first by adding one rectangle of Akasa foam right on top of the middle "post" in the cup. This made my ears extremely annoyed. I think it boosts the upper mids or lower treble too much...somehow. It's nearly touching that felt backed driver.

I removed this piece and it was slightly better and less fatiguing but still tired my ears out. I experimented by taping the outside vents with regular scotch tape. The sound was now a bit more clear and not quite as fatiguing. How does that happen?!

Right now I'm experimenting with material on the driver behind the earpad. Right now I'm using cabinet liner with holes in it and then a piece of very thin foam over that. You'd think the liner screws up the sound, but it has less of a negative effect on the sound than the foam! I'm using the default foam from my HD-600. The foam seems to help the bass in some way, however that's possible.

Sadly the above configuration is the only way I could make mine sound good

Previously no matter what I tried it was always so muffled and the highs were extremely chopped off! That's with all the configurations found in this and other threads. It wasn't overdampened and I'm sure of that.

I still find these headphones so fatiguing even when the volume is low, despite them being quite neutral sounding now.

IME the blutak doesn't help a whole lot.  You really need something like dynamat which I've used personally or maybe bitumen,  modeling clay, or plasticine which others have reported good results with.  The cups could probably use some damping/mass loading as well.

It sounds like you are getting fairly close to my current scheme.

I've never had the Asaka foam, but I have a thin layer of Dynamat goo on the cup to prevent resonance, and a piece of regular felt over the back of the driver.  I have three of the four vent slots covered with electrical tape.

Where you might want to try putting a bit of the foam is around the driver between the baffle and your ear.  

I think that the foam, functionally, is making the cup much larger since the sound bounces around more before coming through.  It's like the foam creates virtual volume within the enclosure, and that can create echoes and delays that muddy up the sound.  I don't want to bash it, since I know some people have had really good experiences with it, but I can see how it could also go wrong fairly easily.

Quote:

Originally Posted by tdockweiler 

Today I decided to give it one last try. I made sure every tiny area of the shell was covered in Akasa foam. Even to the outer edges. I left the vent open. I put everything back together and it sounded terrible...again. The main problem is that the sound was very muffled. Like the driver was covered with a thick fabric.

 

I opened it back up and covered the vent with Akasa foam. Tried again and the sound was now CLEAR!! I don't now why or how this could effect the sound clarity. It doesn't make sense.

 

This is exactly my experience with the vents open vs. closed. Mrspeakers hypothesized it might have something to do with the back pressure required by the driver. I also have my entire cup lined with Akasa like you (which might be overkill?) but I have not tried putting anything on the back of the driver. I thought that adding felt there would reduce the clarity and detail that I was trying to get back but if you think it actually made yours sound better I might give that a shot. Have you tried removing that felt from the back of the driver after you covered the vents again?