Fostex T60RP Teardown

Yes it’s all very complicated. I’ve spent soooo much time with the T50rp and they still surprise me sometimes. But certain things are consistent and dependably good/bad. Front baffle damping or front driver damping isn’t necessary it just means there’s something that needs changing behind the driver or it needs different pads. But when in a pinch you can get away with a lot of half baked damping mods because the drivers are that good. (My favorite ortho driver of all time up to 2012, as I haven’t heard the new models after that). But I’ve heard enough from people I trust to not be very excited. The T50rp driver is the jam.

 

one thing cool I just noticed about this version is they got rid of the big box in the left cup that accepts the cable connection and sends the right channel up through the headband. it's now just a little flat piece. Which means cup volume is basically the same now, something that always bothered me about the T50rp because the cup volume difference could cause an imbalance in FR particularly in the bass (but I took measures to avoid it, never heard it and it was never shown in measurements except probably channel imbalances caused by imbalanced mods)

 

I would replace wimpy foam ring with multiple rings of toilet paper. The density of that foam will affect lower frequencies quite a lot. I'm guessing about 20-30 layers will get a bit more sub bass out of the current design.

You can open up more vents in the rear if you want "moar upper mids" and "less treble". That's how the Mk.3 driver responded IIRC.

Last but not least, instead of the Brainwavz pads, I think you can try these:
https://dekoniaudio.com/product/dekoni-audio-elite-hybrid-earpads-for-select-hifiman-headphones/

And as a bonus, instead of 2-ply paper on top, this is also pretty effective at taming highs and doesn't break the bank:
https://www.amazon.com/ZUINIUBI-Speaker-Cloth-Stereo-Fabric/dp/B01HMBKNSS/

 

Brainwavz earpads are good (at least the pre-memory foam ones were). The problem is the angled version. It’s super bassy. Not recommended.

those dykoni pads are so expensive. Without knowing how they sound I’m going to resist temptation.

 

I bet they’re nice though @Bill-P

 

My t60rp is not selling... so I propose a mod competition: @rhythmdevils vs ______. I donate my t60rp to challenger. Then theyll both send to @purr1n to be judged. Winner keeps their t60rp (loser gets their modstronstity back permanently as well). I nominate @Hands

 

If Hands is too busy, I volunteer!

 

Well mine’s had the driver damping removed which in the T50rp mk2 is a big no no. It’s a very special material I have yet to replicate. So if we both remove driver damping then it’s a fair battle.

Also I’m sick and bedridden so limited but will do my best. Normally this would be fun but under my current circumstances kind of a lot of pressure. I’ll still try to mod them though regardless. I’m excited about the project it’s been a long time. I already bought a bunch of materials.

 

At the risk of boring everyone who's read the T50MKIII thread recently, here are FRs of otherwise (almost) identically-modded T50RP3s with different pads. Flat-plate coupler, no compensation.



To illustrate how I perceive the major tonal differences, the red, green & purple curves are roughly leveled in the bass & lower mids and the blue, purple & aqua curves through the upper mids. Ignore the big roll-off in the low bass, most of it is due to my tiny mic being soft-coupled to the foam (more rigid coupling unrealistically exaggerates mid-bass & lower mids). Also, the big upper-mid dips in the stock & Shure measurements are not as extreme as they appear (others have found the same thing).

The Brainwavz pads are the bassiest; my faves are the cheap no-name ones (purple). The Dekonis are not the ones linked by @Bill-P above but are the symmetrical, all-pleather Tx0 versions. Hybrids would likely be less bassy.

@rhythmdevils , @E_Schaaf : this modding noob would be stoked to see you guys do this (great idea @Philimon !). Results could be sent to @purr1n as referee for evaluation & measurement.

 

Lol too bad we’re doing it with the worst T50rp but that was kind of part of the fun. Maybe less obsession to make them perfect. Well thanks a lot!!

 

I forgot Purr1n removed the back damping. You’re right, they would have to both be made equal. Somebody once said they asked one of the tuning companies about mk2 vs mk3 driver and they answered with that it doesnt matter because they replace the back damping material in either case... so its doable. Suggestions anyone? OR swap the front baffle with a new t50rpmk3?

Take as long as you want/need rythmdevils and challenger.

Great!

 

Doable but not recommended with the mk2 there’s lots of (Or should I say mostly?) shitty sounding T50rp’s out there. But who knows with the T60rp thicker damping and hole. Purr1n wasn’t dumb for trying removing it. Gotta try everything.

 

@rhythmdevils if it's you and me doing the mods, let me know if you've done anything irreversible on your T60rp so I can duplicate and we can start in the same place. Is this what you meant a few posts back about about yours having no rear driver paper? Or was that on a T50?

My only experience modding T--RP was a single pair of T50rpmk2's I did in one marathon modding session with a friend, no measurements, just subjective listening and about 6 hours uninterrupted. He kept them afterwards. I'm sure you've got a head start with what does and doesn't work with this type of headphone, but I've got a whole bunch of materials from modding hifimans, senns, and dynamic-driver fostexes. And about 30 pad types. I do have a T-X0 here too I never got around to working on.

Regardless, let's both aim to meet or exceed the standard set by the LFF Paradox Slant, since those are kind of the 'gold standard' of fairly well-known T--RP mods. I'll have to dig up some EARS measurements from when I borrowed a pair from @captkirk

No time pressure on my end, I'm not really the competitive type as a general statement, just looking forward to the experience. In fact I'd love your feedback on my TH900 mod in the future, I've spent about 9 months with those, finally got to a place where I don't want to change anything.

 

great! Yeah my T60rp has the driver damping (“paper”) removed so you’d have to remove yours as well for us to start at the same place.

I like your attitude about this! Just fun.

If hands does this maybe we can get you one as well and make it a 3 way.

I’d love to audition your modded TH900 at some point. I’m setting up a desktop rig right now so maybe after thats set up so I can hear them at their best. I’ll send you a pm when I’m ready.

 

Too bad Hands, and thank you for sharing your ideas and knowledge. Purr1n I suspect will be down. PM incoming E_Schaff.

 

I got the T60rp in the mail. It’s actually really purdy in person. And the baffle has a thin lip for attaching earpads! Awesome! No more stretching earpads on a T20rp for days then painfully and carefully stretching it over the baffle plus cup edge. Nice one. Im curious if this change pushes the baffle further away from the cup increasing cup volume which may compensate for the smaller cup volume caused by the thickness of the wood cups. But just conjecture. I’ll investigate.