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post #2971 of 10601
Quote:
Originally Posted by AnotherN00b View Post

JoelPierce and others did a lot of experimenting with transpore and micropore tape on the back of the driver about a year ago and it was pretty much rejected as a failure

the major drawback I'm reading/deducting is that once the stock membrane is gone, you are forced to close the cups side vents otherwise no more bass for you due to the lack of driver back pressure....and bye bye amazing 3D SS(especially w/ angled earpads).

maybe it can be replaced by something else, but how will their glue age?
Edited by leeperry - 9/28/11 at 6:21am
post #2972 of 10601
Quote:
Originally Posted by leeperry View Post

 the major drawback I'm reading/deducting is that once the stock membrane is gone, you are forced to close the cups side vents otherwise no more bass for you due to the lack of driver back pressure....and bye bye amazing 3D SS(especially w/ angled earpads).

maybe it can be replaced by something else, but how will their glue age?


As far as I know, the opposite is true. The best way to increase bass is to remove the stock white material and cover it with thick felt. From this point on, port tuning is necessary. With my configuration, half a slit open provided good strong bass without too much bleed into the mid-range. However now I am actually using a piece of electrical tape over the port with 5-7 pin holes poked. I get a great amount of controlled bass, but a nice clarity to the sound as well.

 

Until I removed the white material, I just wasn't able to get adequate bass for my tastes. And I am by no means a bass head......

 

post #2973 of 10601
I get crazy thick bass, it all lies in replacing the driver front felt IME. If I leave the driver front naked, it's uber-shrill and bass shy.

All roads lead to Rome I guess, but at least I can leave the side vents open tongue.gif
Edited by leeperry - 9/28/11 at 6:48am
post #2974 of 10601

Check FlySweep's posts just above.  He's reports terrific results with 3M Nexcare paper tape x 3 layers on the driver backs where I failed with 1 layer of similar, but apparently different enough, generic paper tape.  For those who destroyed the white felt during removal, FlySweep's discovery is a viable alternative to restoring great SQ if you are not a bass head.

 

Check my T50RP Mod Summary for details about how to remove the stock white driver felt in one piece.  I've done this on 2 sets and successfully re-installed them with no loss of SQ.  This method allows more flexibility in trying out all sorts of mods. You can peel away the white felt without fear of being unhappy with the results because now it is reversible.  

 

T50RP Mod Summary:

 

 http://www.head-fi.org/t/452404/just-listened-to-some-fostex-t50rps-today-wow/2640#post_7768186   (Post 2647 - revised with new information added)

 

 

T50RP Modification Summary Links:  

 

http://www.head-fi.org/t/571549/fostex-t50rp-modification-summary-links  (Thanks to ardilla)

 

Quote:
Originally Posted by AnotherN00b View Post

JoelPierce and others did a lot of experimenting with transpore and micropore tape on the back of the driver about a year ago and it was pretty much rejected as a failure from what I recall. That's why a lot of us are still gun shy about removing the stock white material until mrspeakers' rastapants mod championed that approach. I was getting ready to make my plunge soon (waiting for the LFF and latest mrspeakers variations) but now I'm hesitant again after all your (BMF) trials and conclusion that the stock material has the best overall SQ. So confusing!!
 



 



 

post #2975 of 10601

Interesting.  If I understand correctly, you have removed the white driver felt from the back of the drivers, left the driver backs "naked", and added thick felt to the ear side of the drivers.  The drivers are bipole so I wonder if the mod effects are essentially the same with thick felt on the front or on the back of the drivers?
 

Quote:
Originally Posted by leeperry View Post

I get crazy thick bass, it all lies in replacing the driver front felt IME. If I leave the driver front naked, it's uber-shrill and bass shy.

All roads lead to Rome I guess, but at least I can leave the side vents open tongue.gif


 

post #2976 of 10601
Quote:
Originally Posted by KneelJung View Post

Interesting post Arnaud. I'm not sure I completely understood it, but since we seem to be on the topic of different sound damping materials I was wondering if anyone had considered sound dampening paint, I've seen a couple of different kinds used for dampening sound in boats, Noxudol 3101 and Silent Running. Both products seem to work on the principle that sound energy and vibrations are converted into heat. So I'm curious if anyone else has used the stuff or think it's a viable dampening material to try in the T50? 

Quote:
Originally Posted by KneelJung View Post
The heat generated is minute. If you click on that silent running link they have an explanation of how their product works. What makes me curious though is the way it dampens sound and vibration (plasticky resonance). There is also a video on that link that is really interesting. My thinking is if it can dampen the noise coming from that machine the way it does it could certainly dampen the resonances in the T50. The flip side is why reinvent the wheel. I'm pretty happy with the paxmate. Although it's been about a month since I've listened to them. I loaned them to Questhate who has since bought a pair of his own and he forwarded them to Tyll to measure, Like you my coniferating skills reading FR graphs and charts are next to Nil, hopefully I can glean something. My SR60's with the African Blackwood cups and the African Mahogany driver housings are also being measured. So hopefully I'll have something interesting to add to both threads soon.


You're absolutely correct this paint has nothing to do with heat absorption... It's referred as "free layer damping" and is essentially any kind of adhesive material with some elastomer type compound which takes vibration energy away at every cycle the material is squeeze / release. It's nowhere near optimal in terms of weight / performance ratio (there are so called constrained layer damping material to achieve this) and is typically tuned for a given application but there are chances it would work in this application if really one of the issue is spurious excitation of the baffle plate (I had hard time believing it but you guys seem to have consistently shown such kind of dampening treatment is effective). I could actually potentially simulation the damping performance of such free layer damping if I had the properties of the various layers. It's easy for the baffle plate but I'd have to take a wild guess on the paint performance...

 

Quote:
Originally Posted by kkl10 View Post

Hey there, arnaud!

 

I was wondering if you could plot simulations like ^ that for more popular materials like wool felt or cotton or even paxmate?

Or do you ANYBODY?! know where one can find a sort of online database with such kind of information for different materials?

 

It would be information of great value for a lot of us modders...

I don't think there's such kind of information on Head-fi...

 

Thanks!

 


I actually was a bit hesitant to post such kind of absorption result because the software I use is sold to make that kind of prediction among other things so I would need to get approval to help further.  Alternatively, you should find such tables in any loudspeaker design book, I found the following examples through google:

 

http://books.google.com/books?id=kgY8URS_4O0C&pg=PA31&dq=sound+absorber+material+performance+table&hl=en&ei=WyuDTr3POoXKmAXzkqVX&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDQQ6AEwATgK#v=onepage&q&f=false

 

http://books.google.com/books?id=ktkrzNp8zCAC&pg=PT59&dq=fiberglass+sound+absorption&hl=en&ei=fyyDTqWEOujHmAXa6-BO&sa=X&oi=book_result&ct=result&resnum=6&ved=0CEYQ6AEwBQ#v=onepage&q=fiberglass%20sound%20absorption&f=false

 

 

Quote:
Originally Posted by bluemonkeyflyer View Post

arnaud,

 

Thank you for taking the time to answer my question with such detail and rich data - Brilliant!  I understood the second part of my question but could not get my head around how loose fill material increases effective cup volume  Very interesting and practical information.


I know it is very counter intuitive. You add material and magically the volume feels bigger? What kind of horse s. is that theory?! ;). It is well known in the world of loudspeaker DIY though (for instance, you need to factor in the effect of filling material when calculating the effective volume of the rear cavity loading a speaker in sealed or ported enclosure)... 

 

post #2977 of 10601
Quote:
Originally Posted by LFF View Post

Hey....

 

I've paid my dues....time after time.....
 


 

I think i spoke too soon..I just bought a headphone amp that could be quite useful for these headphones as well as my DT880 and Magnums. I currently have a DIY PPAv2 amp which I consider to be a solid performer at not much cost but the amp is supposed to be a good performer and too high a cost :P I'm hoping it does well with the T50RP since the specs have it givingmore power than the PPAv2 although I'm not sure what the specs are at but the amp is supposed to be quite powerful.

post #2978 of 10601

Hi,

 

The material in the cup slows down the speed of sound compared to the speed of sound in the open air, thus making the cup appear bigger,  This link will take you to a page with some illustrative graphs.  As you can see the change is frequency dependent and is altered by the density of the material.

 

http://www.t-linespeakers.org/projects/tlB/response.html

 

There is a link on that page which takes you to the Bradbury's Fiber Equations.  Follow it at your own risk!

 

Regards,

Bob

post #2979 of 10601

A pair of T40RPs on their way to doggyL3000.gif

I will try FlySweep's 3M mod soon with my T50RPs biggrin.gif

post #2980 of 10601
Quote:
Originally Posted by LFF View Post

I'm really curious how mine would sound with O2 pads.

 

Yes...I'm still trying to avoiding spending money......


Welcome to headfi, sorry about the .... waitaminnit...

 

 

post #2981 of 10601

Bought a Monster Studio replacement cable last night, and will probably receive it in a week or so.  The cable right now, after months and months fidgeting, is fine.  Originally, I have serious static and L/R balance issues, but for some unknown reason, has mostly disappeared a couple of weeks ago (there is still some bit of L/R imbalance).

 

The reason I got the replacement cable is because I am going to travel extensively over the next 3 months for work, and will take my T50RPs with me (I know, looks like a freak with those cans in public), and would want to do without the bulking stock cable + Grado 1/8 to 1/4 adaptor cable.  I will report back if there are any sonic differences.

post #2982 of 10601
Quote:
Originally Posted by ambchang View Post

 I will report back if there are any sonic differences.



I doubt it, but if you think there are, that's fine for you :)

 

I will post pics of my T50RP 2.0 later.

post #2983 of 10601
Originally Posted by LFF View Post


Hey...if you're happy with them then that is all that matters. If you want to vet them, there is only one way....send them to Purrin for objective and subjective impressions.

 

It's a shame that not many people have commented on my Paradox headphones. At least 20 people have heard them.....

 

If you do get that second, I'm always willing to give them the Paradox treatment.

 


No kidding?  20 people.. come on folks!  I've got great respect for your ears so I'm very surprised to not see impressions.  I'd love to have you mod these to Paradox specs.  Since I've got a handle on my mods it won't be a problem to duplicate on another set of T50RPs (I'l be ordering soon).. I'll be PM'ing you in the near future, LFF..

 

 

Originally Posted by bluemonkeyflyer View Post

That is what I was trying to accomplish last night - to find a good substitute for the white driver felt.  My test failed.  I am happy to hear you achieved good results using 3 layers of paper tape.  Oddly, I used only 1 layer of paper tape over the backs of the naked drivers and all I got was tin can alley sound.  I figured the glue on the paper tape essentially rendered it impermeable, or non-breathable, and resulted in constricted, poor sound quality.  I glued the stock white driver felt in place and all was good, again.  

 

I could not tell any visible difference between generic and name brand paper tape so I went with the generic brand.  I suppose there could be a permeable difference not discernible to the naked eye so I'll stop by the drug store and buy some 3M NexCare paper tape for repeating the test.

 

FWIW, I found that 1 layer of craft felt and 1 to 3 layers of Organdi over the naked drivers produce the same massive bass slam and bleed-over into the mid-range that you describe.  It sounds like you have found a viable substitute for the stock white driver felt.  Way to Go, FlySweep!

 

My exact concern too.. I was pleasantly surprised that it didn't constrict the sound.  It's certainly on the brighter side, but tinny it is not.  Re: the bleed.. it was one of the toughest things to control with the vents, for me anyways.  I simply cannot stand bass bleed into the lower midrange or any manner of a mid bass hump.  I'm very happy to find the tape keeps that all in check but doesn't affect the sub bass.  If there is anything people might desire from my mods (speaking of which, I need to come up with a name), it might be more bass slam.  Right now, it's tight and quick.  I'm going to work at tuning this with additional layers of tape (in various regions of the driver back) instead of modding the felt covering the vents.

 


Originally Posted by bluemonkeyflyer View Post

FlySweep,

 

Are these your mods?

 

1.  1 layer of Paxmate or Silverstone (4 mm thick) neatly applied to the entire inner cup surfaces.

2.  Stiff, 2 mm craft felt over the interior bass port vents (after removing the stock black felt).

3.  3 layers of 3M NexCare paper tape on the backs of the drivers (after removing the stock white driver felt).

4.  Plasticine in the baffles.

5.  Stax O2 ear pads

 

If this is correct and if 3 layers of 3M paper tape equates to the stock white driver felt, then the variables I need to test are whether or not there is a difference between the stock black bass port felt vs. stiff 2 mm craft felt on the bass ports, ear pad "rolling", and add more Paxmate to cover any exposed areas in my cups.


Spot on, BMF.  I'd say 3 layers of 3M paper tape is a hair thicker than the stock, white felt.  2 layers is closer, if not identical to stock.

 

If I had to describe the sound of my mods, I'd say tight, bass.. no midbass hump.. balanced midrange (that's very slightly midforward).. and a clean, crisp airy treble.

 

I'm listening to John Scofield's "A Go Go" right now and the tuning seems perfect for the recording.  I can hear Billy Martin's slightest nuances in his masterful percussion work.  Scofield's soulful, funky guitar has never sounded so lively & colorful.  Chris Wood's bass playing is tight and possesses excellent speed and clarity.  I can clearly discern how well my mods control the midbass hump with this recording too cause Chris Wood goes ham on the upright.  I heard it heavily dominate the sound & bleed into the midrange with the craft felt backing.  It's much more in line with everything else right now.. but presence is not sacrificed.

 

The other thing that jumps out to me is the instrument separation.  It sounds like I'm in the studio with these guys hearing it played live.  Billy Martin's drums in particular sound sooo damn good!  Every flourish and minute touch sound clear as day and accurate.  The tonality of the drums is spot on.. like everything else.  Medeski's keyboard playing is so fleshed out.. I just want to hear this on repeat all day.

 

Also, I've got the v-moda 3.5mm cable LFF mentioned a few pages back, on the way.


Edited by FlySweep - 9/28/11 at 12:37pm
post #2984 of 10601

Hello, 

 

greetings from a head-fi noob though I have lurked for a while.

 

If anyone's interested there is a mod kit on ebay:

 

 

 

http://www.ebay.co.uk/itm/Fostex-T50rp-super-mod-kit-includes-paxmate-newplast-/110747585352?pt=UK_AudioVisualElectronics_HomeAudioHiFi_Headphones&hash=item19c9120b48#ht_500wt_1204

 

Any opinions as to whether it's good/worth it? I'm in the UK so this seems like a good option.

 

Anyone here actually tried it?

 

regards, itsastickup

post #2985 of 10601

 

 

 

I'm finding the T50rp a bit too low volume driven by my clip+. Has anyone tried them with a FiiO 5: does it do it justice or would I be totally undermining the SQ? 

 

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