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

b0wl1ng · Sep 20, 2011 at 5:25 AM

Unless you line them with lead they are quite light , any of the many mods on the thread drastically improve the sound .

dogears · Sep 20, 2011 at 5:31 AM

Might help: Fostex T50RP Mod Links

Quote:

pbjabba said:
I just ordered my T50rp from Front End Audio, ~$110 shipped to Australia. Still on backorder though, hopefully mine will be sent from the shipment that supposedly comes in on the 30th.

I have to admit I haven't read the whole thread, I have some questions about the mods... Which mods affect which aspects of the sound? For example is there a particular mod that enhances treble, or do they just make the sound "better" in general? Also, how are people finding the weight of these once they're all stuffed full of plasticine/blutak/etc? Apologies for my ignorance

ardilla · Sep 20, 2011 at 6:40 AM

x2

I also want to know what mods does what to the sound....

FlySweep · Sep 20, 2011 at 6:46 AM

All mods completed except for sealing the inner cup of the vent seal (to be done when correct tuning is achieved). Waiting for O2 pads which should arrive this week. I did open the small, earside vent that goes down into the cup.

The bass took a serious jump up in impact & presence.. impressive. It's nice, but uncontrolled, too dominating, and lacks some clarity. There's a spike somewhere in the lower midrange/upper mid-bass area causing vocals to sound honky. Sorry, I can't think of a better word to describe it. It isn't all that natural sounding, a little too dark and warm right now. Treble is there, it's clean, but it sounds a bit too pushed back behind all the warmth & vocal monkey business going on. I've covered 90% of the cup-side vents vertically (so a very small amount of each of the vent slits are open, opposed to sealing all but one vent)... could this be an issue?

My T50RPs have maybe three or fours of of play time on them.. do I just need to let them burn in so they'll clear up? I know a few people mentioned they reall opened up after some time playing.. but I wasn't sure if there was a wider consensus on that.

Status <pending> : How to bribe LFF's wife to sew my 003 pads onto the T50RP

micmacmo · Sep 20, 2011 at 10:24 AM

As my T50RP burned in, I listened in occasionally. To my ears, it took more than 10 hours for the Fostex to open up, maybe approaching 50 hours. In between my "peek listens," I was listening to my regular cans for extended periods of time, which I think gave me a reasonable baseline for comparison.

mrspeakers · Sep 20, 2011 at 10:50 AM

flysweep said:
All mods completed except for sealing the inner cup of the vent seal (to be done when correct tuning is achieved). Waiting for O2 pads which should arrive this week. I did open the small, earside vent that goes down into the cup.

The bass took a serious jump up in impact & presence.. impressive. It's nice, but uncontrolled, too dominating, and lacks some clarity. There's a spike somewhere in the lower midrange/upper mid-bass area causing vocals to sound honky. Sorry, I can't think of a better word to describe it. It isn't all that natural sounding, a little too dark and warm right now. Treble is there, it's clean, but it sounds a bit too pushed back behind all the warmth & vocal monkey business going on. I've covered 90% of the cup-side vents vertically (so a very small amount of each of the vent slits are open, opposed to sealing all but one vent)... could this be an issue?

My T50RPs have maybe three or fours of of play time on them.. do I just need to let them burn in so they'll clear up? I know a few people mentioned they reall opened up after some time playing.. but I wasn't sure if there was a wider consensus on that.

Status <pending> : How to bribe LFF's wife to sew my 003 pads onto the T50RP

To get the bass and mid bass corrected you have to mostly close off the vent with electrical tape. I experimented with tape on the outside until the balance was right then put the tape inside. For me, a tiny 2 to 3 mm gap along one vent line only suffices. Closed you lose the bass, more it's way to bottom heavy and the lower mids suffer.

bluemonkeyflyer · Sep 20, 2011 at 12:39 PM

Fostex T50RP Modification: A Summary of Methods, Materials,

and Their Possible Effects

bluemonkeyflyer - Modding Noob Extraordinaire

September 20, 2011

Disclaimers, IMHO, My 2 Cents, YMMV...

I am a beginner, mere novice, and noob-extraordinaire when it comes to modding headphones. I read this entire thread and most of the huge Orthodynamic Roundup forum three months ago before I joined "The Mod Squad." I bought 2 sets of T50RP's and began my quest: To approach the sound quality (SQ) of my reference set of cans - Audeze's LCD2's. Eventually, I bought 6 more sets of T50RP's to mod that will make great gifts. I selected and tried a multitude of mods described by many head-fi members; most from forum members with vast experience and some from members who are rank amateurs just like me. I have learned a lot through the process of systematically making one mod at a time and comparing to my other stock set of T50RP's and my Audeze LCD2's.

There is always, it seems, the opportunity to learn more and try just one more tweak. Hobby? Obsession? Healthy addiction? Whatever, this has been, and continues to be, a fun learning experience that pays Big Dividends ---> YOU can easily transform a $75 pair of headphones and less than $10 worth of modding materials, yielding ~ 80% to 85% of the SQ Goodness of a $950 set of LCD2's. The Law of Diminishing Returns obviously applies considering that last 20% of LCD2 SQ sweetness costs an extra $850! Granted, modified T50RP's will never match the full awesomeness of Audeze's LCD2, but come very close and allow everyone with time, basic skills and common materials to own an outstanding set of planar magnetic headphones for less than $100.00.

What follows is my summary of various mods you can easily make to Fostex T50RP headphones, associated with my limited understanding and explanation of the principles, techniques, and possible results achieved from the process. Mods I describe below and chose to implement, as well as their SQ effects, are based upon the inherent limitations of my individual auditory perceptual system (my ears, Ha!) my personal preferences, my particular experiential phenomenology, and, well, my opinions; and are further limited by my Noob-ness --> my lack of experience and insufficient knowledge base. As such, feel free to disagree and correct any errors of commission/omission I may have made as wells as misconceptions. I am always open to constructive criticism, advice, and new/better ways of doing things.

Before you begin your first mod, read everything in this forum, choose methods and modding materials that are available and make sense to you, go slowly, use the scientific method by making only one mod at a time in order to accurately judge its effects against a reference, and most of all...have fun. Please "give back" to the forum by posting your results - your successes and your failures - so we can all benefit by learning from one another. Pictures of your mods are appreciated and extremely helpful.

Finally, I try to give credit where credit is due for various mods and methods but likely made mistakes and left out key contributors due to my faulty memory. If you contributed an idea or invented any of the modification techniques described below, and I failed to mention you, please send me a PM and I will make the corrections.

Mod 1: See post #1786 on page 120 of this forum for Pictures of my first mod completed on 7-3-2011.

Mod 2: See post #2663 on page 178 of this forum for Pictures of my version of mrspeakers Rastapants mods completed on 9-19-2011.

Mod 3: See post #2716 on page 182 of this forum for Pictures of my third mod (BMF) completed on 9-21-2011.

Mod 4: See post #3058 on page 204 of this forum for Pictures of my fourth mod (BMF) completed on 9-29-2011.

For a copy of this Summary with step-by-step instructions and pictures, email me at --> bluemonkeyglider@gmail.com

How to Open and Re-assemble Fostex T50RP Headphones:

Do not try to snap-off the horseshoe-shaped front hanger holder (#8) from the outside of the cups (#1) at the articulating bearing. If you do, you will snap-off the rear hanger holders' (#9) 2 plastic protrusions that fit into the holes at either end of the metal hangers (#7). Instead, refer to the instructions and exploded drawing, below.

Experienced T50RP modders:

1. Remove the plastic plate (#18) to gain access to the the screw (#20) that attaches the hanger (#7), rear hanger holder (#9), and front hanger holder (#8) to the cups.

First timers:

1. Remove the earpads (#3) from the baffles/cups (#12 and #1) by carefully pulling them away from 4 dabs of white adhesive around the perimeter of the baffles.

2. Remove all 4 outside baffle screws (#23). Do not remove the other three inner screws (#23) that hold the drivers to the baffles. Be careful to not drop/lose these tiny screws; they cost $1.50 EACH. Use a magnetic screw driver.

3. Gently separate the baffles (#12) from the cups (Left housing #1 and Right housing #2), taking care to not detach the hook-up wires from their delicate solder points on the drivers (#15) and headphone jacks (#16).

4. Use an Xacto knife around the perimeter seam of the plastic plate (#18) glued onto the round compartment located at the center/inside of the cups, directly in-line with the headband hanger holder (#9 and #8) and in-line with the center square of the back side of the driver (#15). After loosening the glue in the seam, you can pry the plate off which gives access to the screw (#20) that secures the hanger (#7), rear hanger holder (#9), and front hanger holder (#8) to the cup (#1).

5. Remove the screw (#20) which allows disassembly of the hanger (#7), rear hanger holder (#9), and front hanger holder (#8) from the cup. Re-attach the plastic plate (#18) with rubber cement.

6. When re-assembling, avoid over-tightening the 4 screws (#23) that attach the baffles to the cups in order to prevent stripping the cups' plastic threads. If you happen to strip these threads, Do Not use Lock-Tite! It melts the plastic. Use super glue in the cups' screw holes, instead, and read the directions first to insure it is safe to use with plastic. Use a paperclip to "tamp" the super glue down into the cups' baffle screw holes. Let it dry for 24 hours. Use a 1/16" drill bit and slowly drill out the super glue to the depth of the 4 tiny baffle screws. The baffle screws will tap new threads in the remaining super glue inside the cups' baffle screw holes.

General

http://www.head-fi.org/t/452404/just-listened-to-some-fostex-t50rps-today-wow/2610

See post #2620 for a description of how to remove the stock white felt from the backs of the drivers in one piece. This allows you to save them in case you want to go back to stock. Use acetone at your own risk, and sparingly. Do not use so much that it drains onto the diaphragm and its copper tracing. There may be safer substances. Do your “homework” and read the instructions and safe use guidelines.

See post #2611 for an explanation about the small vent hole on the ear side of the baffles.

There are 4 slot lines at the bottom of the cups and covered internally by stiff, black felt. These slots are the bass ports. There are 4 sealed slot lines at the top of the cups that have no function.

Warning!

DO NOT Use Loctite BLUE 242 on your Fostex T50RP! It literally melted the screw holes in my first pair. After the fact, I read the tiny print on the bottle and it clearly says "DO Not Use With Plastics." -----> Note to Myself: Always read the instructions before using anything!

My first modded set of T50RP's have been opened and closed over 50 times for as many mod experiments. It will now be put to rest but the drivers will be transplanted into Smeggy TP1's ...Thanks Smeggy!

Fostex T50RP Mods and Their Possible Effects:

1. Mass load the backs of the baffles with plasticine (modeling clay) - to reduce resonance. You may also try Blue Tack or similar materials but plasticine seems to be the most highly recommended and is what I used with great results. You can get plasticine at art supply stores or ebay and Newplast from Amazon <dot> co.uk. Be sure to Not fill the small hole located at the top left side of the driver frame --> when the rear of the driver/baffle is oriented with the solder connections at the bottom, closest to your sitting/viewing position. Thanks to many head-fi'ers for this mod and others, below, including Smeggy, wualta, Sachu, boilermakerfan, mrspeakers, joelpearce, leeperry, dBel84, Kabeer, rhythmdevils, and several others.

2. Akasa Paxmate Plus (or similar 4 mm acoustic foam) - 1 layer on the bottom and sides of the interior cups to reduce reflections. Using too much (more than one layer) reduces the interior cup chamber volume which may negatively effect the SQ. You can get Paxmate Plus at performance-pcs <dot> com and sidewindercomputers <dot> com. You can get Silverstone acoustic foam from Amazon. Props to leeperry, joelpearce, and others.

3. The 4 vent slots located at the bottom of the cups and covered with stock black felt - for tuning the bass. Removing it and leaving all 4 slots completely open results in much more bass BUT the bass is boomy/slow and muddies the lower mid frequencies causing vocals to sound muffled. Sealing 3.75 of the 4 slots cleans-up and speeds the bass with excellent extension, IMO. mrspeakers recommends closing off all of 3 slots and all but 2 to 4 mm of the 4th slot line.

4. Small "pressure equalization vent" located at the ear side of the baffle near the top that communicates with the interior cup chamber through the driver frame - The Baffle Port.

5. Reflex dot - Thin rubber or plastic adhesive-backed "feet" used on the bottom of glass bowls and vases; porous or non-porous tape, felt dots, paper, or similar - Apply to the center square (or more) of the back side of the drivers to increase treble extension. Credit to Smeggy, Sachu, wualta, and others. Sachu and joelpearce are among those who have tried various materials and placements over all the squares on the back of the drivers.

6. Stock white felt on the backs of the drivers - Removing the white felt increases sensitivity so they play louder. You may find some beneficial effects but be ready for dealing with unwanted side-effects including massive bass quantity that's slow and flabby, muddied mids, and veiled treble that require further tuning. For example, after removing the white felt, you can add a square of craft felt over the entire rear side of the drivers to tune the bass, muddied mids, and recessed treble. Alternatively, you can also use various types of tape - I found that 1 to 3 layers of 3M Transpore tape is essentially equivalent to the functionality of stock white driver felt. Installing a reflex dot to the center square on the rear of the drivers may increase treble. Additional tuning of the cup vents (the 4 slots at the bottom of the cups) may be required. If not almost completely closed with tape or Paxmate (3.75 of the 4 slots), bass remains slightly boomy, mids sound slightly muffled, and highs are veiled with little to no air. To my ears, this mod produces pretty good frequency response and Heavy Duty Bass Slam that remains tight and fast. My bias: Don't Remove the White Driver Paper.

I tried all permutations: 1) stock white felt alone, 2) leaving the white felt intact plus adding a reflex dot, "naked" drivers alone after removing the white felt, 3) naked drivers with a reflex dot in the center grid space, 4) removing the white felt and adding a square of craft felt covering the entire rear side of the driver, and 5) removing the white felt and adding a square of craft felt after first installing a reflex dot to the drivers' center square. I like the SQ better with the 5th mod just described. You can get reflex dots a Lowes or Home Depot. You can get craft felt at Michaels, art supply stores, and fabric stores.

I tested the sensitivity with the white felt intact vs. after removing the white felt. I used a Radio Shack digital SPL meter with a homemade headphone adapter to seal the SPL probe to the ear pads. For this, I used a clear, plastic DVD spacer which is the same size as a DVD. I enlarged the center hole to fit the SPL probe. I secured the modified DVD spacer to the SPL probe with duct tape and applied duct tape over the entire surface of the plastic DVD spacer. I set the SPL meter to "Fast", "C Weighting", and 90 dB.

Here's my chain for this test: MacBook Pro --> Apple Lossless Files --> Patricia Barber's "Light My Fire" - the first 90 seconds --> via Toslink cable to CEntrance Dacmini with the volume knob set to the 12 o'clock position --> T50RP:

Stock white felt intact on the drivers = 75 to 85 dB.

Stock white felt removed plus a reflex dot to the center square of the rear driver grid and felt glued to the entire back of the drivers = 83 to 94 dB. This mod produced deep/layered bass, clear vocals, and good treble extension. Props to mrspeakers Rastapants.

7. Cutting away the dust cover felt on the ear side of the baffles - Some find this opens up the treble. The dust cover is very thin and loosely woven. I cut it off one set of phones. I did not hear a difference but this may well be due to my deafness above 12k Hz.

8. Donut of Paxmate, felt, or similar material on the ear side of the baffles and under the ear pads - Some find this improves the SQ and provides a better seal which will increase bass. Some have used various thicknesses to angle the ear pads for better "delivery" of sound to the ear canals. Be sure to not cover any of the driver opening under the dust cover on the ear side of the baffles. Enlarging the ear pad to head internal volume will lower bass and decrease sensitivity.

9. Ear pad rolling - to change the Sound Signature, increase bass, improve isolation, and improve the seal between the ear pads and the baffles. Various pads may improve overall SQ, widen the soundstage if they are "taller" than stock pads by moving the transducers further away from your ears, and they may look snazzier. The most popular pads aside from stock pads are Shure HPAEC840 for ~$18.00 at Amazon and Stax 02 pads for ~ $150.00! HM5 and Fischer FA-003 pads are very comfortable but must be modded to fit because they are too small. See micmacmo's pictorial for a neat method of modding pads.

10. Re-cable - May improve SQ and aesthetics. Wire and plugs are readily available all over the net. Google it. Search ebay.

11. De-solder and directly solder the cable wires to the drivers - May change and improve SQ. But why fix it if it isn't broken? The solder is said to be aluminum and PITA to solder. Why not cut the wires forming "pigtails" that remain attached to the stock solder points?

12. Custom wooden cups - Improve aesthetics But there is No automatic "gimme" that they will sound better. In fact, they can sound much worse.

13. Modify the headband - Improve aesthetics, comfort, and seal.

EDIT:

14. I just couldn't leave this at "13". I have a word document, a LONNNNG word document, that contains information, how-to's, and pictures gleaned from this forum, the massive Orthodynamic Roundup forum and internet search information about modding the T50RP and Sawafuji SFI, re-cabling, wire types and sources, braiding techniques, links, other sources, and more. Anyone who wants a copy can email me at: bluemonkeyglider@gmail.com

Hypotheses about the stock white felt (Thanks JoelPearce ):

1. Maintains a balanced freq range

2. Serves as a big reflex dot to provide treble, and

3. Controls the movement of the driver diaphragm to prevent bass bloating (paraphrased).

My last second and third mods (my version based on mrspeakers Rastapants and my BMF configuration) involved removing the stock white felt. My first series of mods kept the white felt intact. My fourth mod involved testing various materials to replace the stock white felt.

Mods 2 and 3 have SIGNIFICANT bass quantity and some mid-bass bloating. The bass quality is consistently very good across all 4 mods. I had to add a reflex dot to mods2 - 3, I believe, because removing the white felt accentuated the bass end due to greater driver excursion but diminished the treble end of the frequency spectrum. I had to add felt to my second mod and Organdi to my third mod to contain (minimally) the bass slam. By completion of the fourth mod, I solved the massive bass issue by using 3M Transpore tape.

If this is really what's happening, the take home message appears to be this: leave the white felt alone unless you absolutely love bass slam and can add mod components necessary for bring back the treble response and better balance the SQ by removing bass bloat bleed-over into the mids.

If you remove the white felt you have to replace it with something that will serve a similar purpose and that either:

1) Allows less air flow/driver excursion and results in more treble-less bass ---> do this if you like hotter cans. EDIT: Or find a way to get more treble without making an irreversible mess.

2) Allows more air flow/driver excursion and results in less treble-more bass ---> do this if you are a bass head. EDIT: Or find a way to get more bass without removing the stock white driver paper.

3) Allows about the same air flow/driver excursion and results in no significant change in the frequency response ---> then you should leave it alone and avoid re-inventing the wheel.

EDIT: The stock white driver paper, stock black cup vent felt, and dust cover over the ear side of the drivers are your friends.

Full Circle

I've opened, modded, and closed 4 sets of T50RP's 100's of times. I made one modification at a time and compared the results to my LCD2 and another pair of stock T50RP's. Newplast or tungsten putty (homemade) in the baffles and one layer of Paxmate or Acoustipack Lite in the cup floor wells have remained constants across all my mods.

I have tested 5 different types of material for reflex dots and no reflex dot; white felt on and off the back of the drivers; stiff felt, limp felt, thick wool felt, cotton, and no felt in the cups and on the back of the drivers; 1 to 3 layers of Organdi on the back of the drivers; naked drivers; bass ports in stock form, with the stock felt removed from the bass ports, and electrical tape covering 1, 2, 3, 3.5, 3.75, and all 4 bass port slots; dust cover on the ear side of the baffle intact and cut away; acoustic foam on and off the ear side of the baffles; 3M Micropore tape (paper), 3M Transpore tape (perforated flexible plastic), and Rite Aid generic paper tape; and practically every permutation of all these variables. Only 3M Transpore tape provides a viable alternative to the stock white driver felt with similar sound signature, for me.

Fingernail polish is often comprised of acetone and may come with a handy applicator brush just the right size for applying it to the metal grid under the driver white felt. Remember that acetone and other organic solvents are flammable and toxic, so use with caution and insure there are no open flames. Also use it sparingly so it does not drip or run down onto the diaphragm. I do not know whether or not acetone can damage the diaphragm and its copper tracings. Work carefully and you should be able to peel away the white felt in one piece so you can use it later if you want to go back to stock. The white driver felt came off relatively easily on one set but the other was difficult. Once I was able to get one corner started with a knife, both sets required repeated applications of small amounts of acetone because it dries FAST. I found the white felt must be moist in order to peel away cleanly. Water did not work at all. Edit: "Don't do it!"

For me, keeping everything stock and adding only plasticine or Newplast to the baffles and Paxmate or Acoustipack Lite to the cup floor wells produces the best overall balanced SQ. Incremental bass port tuning can be accomplished by varying the number and length of the 4 slot lines on the cups. Treble can be tweaked by using various types and sizes of reflex dots on the center (and/or other) grid square on the driver backs. EDIT: Over-stuffing the cups with cotton, wool, fiberfill, etc. works for me; especially all cotton or 70% cotton and 30% fiberglass.

I would not have been satisfied had I not gone through the laborious process of systematically testing each mod for myself. I am not proposing that this is "the best" mod configuration. I am not suggesting that this mod configuration is "The Way" to go for anyone else. So far, however, this is my favorite mod setup for my ears. I'm not done, though. I have more things in the works.

EDIT: Go to http://www.head-fi.org/a/fostex-t50rp-modification-summary-links-wiki

This is too much fun!

BMF

turimbar1 · Sep 20, 2011 at 1:08 PM

^ very good summary of mods there bluemonkey, add that to the t50rp wiki so we can just link people there whenever someone new wants to get in on this action.

bluemonkeyflyer · Sep 20, 2011 at 1:26 PM

Quote:

turimbar1 said:
^ very good summary of mods there bluemonkey, add that to the t50rp wiki so we can just link people there whenever someone new wants to get in on this action.

Many thanks, turimbar1. I'm guessing a moderator will make that decision.

marcan · Sep 20, 2011 at 1:30 PM

NIce bluemonkey.
For me the 7. Cutting away the dust cover felt on the ear side of the baffles, really open up the trebles. Otherwise they seemed veiled and dark.
The one ear test is not relevant because your brain can compensate the balance. You have to try it with a second t50tp (which I think you have).

rawrster · Sep 20, 2011 at 2:30 PM

Nice summary there. Do you happen to have a picture of the reflex dot? I've always been confused about what that really means or if there are posts on that topic to have a better idea of what it is.

bluemonkeyflyer · Sep 20, 2011 at 2:38 PM

Quote:

rawrster said:
Nice summary there. Do you happen to have a picture of the reflex dot? I've always been confused about what that really means or if there are posts on that topic to have a better idea of what it is.

Yes, I do. I took pictures of the Rastapants mods I completed last night. I will upload them in an hour, or so.

Thanks for the feedback.

AnotherN00b · Sep 20, 2011 at 2:46 PM

+1 very nice. Would also like to see this knowledge transferred to a wiki where it can be more readily accessed and referenced. Not sure what the policy is for contributing to wikiphonia or creating a new wiki page but it would be nice! Thanks for taking the time to detail all of this so thoroughly!

Quote:

turimbar1 said:
^ very good summary of mods there bluemonkey, add that to the t50rp wiki so we can just link people there whenever someone new wants to get in on this action.

Questhate · Sep 20, 2011 at 4:02 PM

Great work, bluemonkeyflyer. It sums up all of the useful information littered throughout this thread very nicely. I agree that the post should be wiki'd.

SLaRe · Sep 20, 2011 at 4:35 PM

Some pics of the mods would help people a lot.

This should be pinned

Great work bluemonkey

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