[JohnR]

Thought I better start a new thread on this 'phone, initial discussion started here:

http://www.audiocircle.com/index.php?topic=105729.0

I got a pair yesterday. Initial impressions, OK but not really anything to write home about, so they will need more time before commenting. Still much better than other phones for the price that I've had. However I'd say the bass is OK, not overly light as others have said.

The main issue is the image is shifted to the right, seems like about 2-3 dB (by adjusting the channel level so that the image of a mono signal is centered). Although it may be a frequency response thing rather than purely a levels thing, as I did find somewhere some differences in the left-right measurements. I may try to see if I can get some sort of measurement of them. (I suspect that the supplier is not going to treat this as a warranty issue.)

[sharpsuxx]

Hey John,
I have a set of T50rps as well, I was enthused on them after reading about the ThunderPants on Head Fi.  I agree they are not terribly exciting at first, but they do take very well to mods, and they are cheap too boot. 

I can't say that mine have any sort of off center image at all.  I have tested with Mono tracks and just good center focuses vocal music and no issues with my pair must be something wrong with your unit.  It could also be the rather poor headphone connection on the side, you may notice after hefty wear and tear it tends to get channel imbalance and drop out after a while.

To be honest the can design on these is piss poor.  They aren't particularly sturdy, and the vents on the cans make the sound worse rather than better.  I found that by sealing the vents with a couple layers of electrical tape and running a piece around the edge of the pad the isolation is much better and the sound stage tends to open up quite a bit.  I also did some tinkering with the headphone plug to give it a stiffer connection.  The drivers in these guys are phenomenal when you get down to it to hear them, the implementation in these cans is uninspired to be polite.

I am listening to my duck tape modded T50-RPs at work right now in fact, pretty happy with them at the moment.  I will probably take them apart recable them and hard-wire the headphone cable directly to the drivers eventually and maybe even re-cup them with some wood or carbon fiber cups if I am feeling frisky.

[sharpsuxx]

PS if you are patient these can be had for $75.

[JohnR]

Hi, thanks for posting. Good info 

The drivers in these guys are phenomenal when you get down to it to hear them, the implementation in these cans is uninspired to be polite.

That's what I'm hoping. I just need to make sure that both drivers are good, if the imbalance is something to do with the cups or mounting etc then it's not really a concern.

[sharpsuxx]

In Case you haven't read the whole thunder Pants thread on Headfi hear is the gist I got plus some things I learned on my own:

-Mass load the Cups
-Seal the Vents
-Better Seating for the headphone connector
-Bend the metal clamps for tighter fit and a better seal
-Improve the seal where the factory ear pads attach
-Add padding to the headband for comfort
-Add a "reflex dot" on the back of the driver for smoother treble
-Improve Damping inside the cabinet
-Cut off the factory felt off of the driver
-The factory clips that attach the metal pieces to the phones will break eventually, so start thinking of methods to fix them.
-My personal favorite rule for headphone Mods, "If you can't Duck it," Well you know the rest 

Enjoy the ride,

[neobop]

Is the reflex dot to smooth out or increase the treble?

There's a little vent near the top of the driver. I believe this should stay opened with a sealed enclosure.  You can seal it with a vented enclosure. I have a new pr and it came w/o the felt behind the driver.

Rather than blindly follow someone else recipe, if you're keeping the stock enclosure you can experiment. I'm getting great results with a single slot loaded vent. I just switched back to the stock pads from the Shure 840. The Shure pads increase the bass and make the top more distant. I was getting a little too much bass. The slot loaded enclosure sounds like it goes all the way down, to below 20Hz. Maybe I'll try a sealed enclosure. It's just that it sounds really nice the way it is with the slot loaded basshead mod LOL.  I'm thinking of making wood pieces for the vents. Still a work in progress.

[eclein]

Interesting stuff, how are they for comfort??? I see in the picture a pen stretched across between ear cups, are they headclampers???

[neobop]

No, they're really comfy. Some people complain that their ears touch the baffles with stock pads. The 840 pads are about 1/8" thicker, seal better, and feel a little nicer. Most people like them better, although stock is okay for me.  I put the pen there so you see the driver on the other side. I cut back the grill cloth on the baffle and the 840 pads. Stock pads have no grill cloth.

Mine also came with the Rt side louder than the Lt. I'm pretty sure this is the connection between the jack and plug coming into the phones. I was able to fix it by playing with the plug, but this is a temporary fix. The solution is to replace the jack or hard wire.

Anyone can buy these for $74 at B & H in NYC. 

[JohnR]

I'm not able to get measurements to prove that the right is louder than the left. I don't have a proper headphone measurement rig, so I just put the mic a) right up on the grill and b) in between the phones with them sitting on the table. These are not intended to be absolute measurements but a way to compare things.

Here is the T50RP. Top two traces are left and right (a), bottom two are left and right (b).



Here for comparison is the Sennheiser HD-598:



I wouldn't assume that this means that the T50 is lacking in bass - I'm not measuring on a "head" so the phones will behave differently when they are put on a head. The main point is that the measurements of the left and right phones doesn't seem to indicate a left-right imbalance. Sort of a non-result, really 

[neobop]

Here's what Head Room measured for the 598:
http://www.headphone.com/headphones/sennheiser-hd-598.php

If you click on the graph you can compare it to other phones. Unfortunately they don't sell Fostex.

[JohnR]

Thanks for that link neobop. It looks like on-ear there's a general tilt that lifts below 1 kHz. I'll try blocking some of the slots to see what happens - just a bit of masking tape?

[JohnR]

A bit OT but here's an interesting link on measuring headphones:

http://www.innerfidelity.com/content/headphone-measurement-proceedures-frequency-response

Quite a number of phones measured (inc T50RP):

http://www.innerfidelity.com/headphone-data-sheet-downloads

[eclein]

John usually masking tape works great for that type of mod because its removable and easy to place. If you do it try blocking a whole bunch and then listen so you can hear where its effecting the sound, and what type of effect its having that way when you make subtle adjustments later its easier to pick out the change.

Follow me? Once you know what type of change your hearing large scale its easier to tweak smaller changes and tune them in better.

[JohnR]

Ed - good approach. I'd like to know what the measurable effect is though, at least at some level. Putting masking tape over the slots didn't have the effect I thought - blue is without any tape, red is with masking tape.



Not sure what to make of this 

[neobop]

Innerfidelity is a great link. Thanks for posting that. The plots differ somewhat from HeadRoom, especially in the bass. Still, it makes it easier to get an idea of the character of the sound if you can't audition.

On the inside the T50 (new ones) has cloth dampers over the ports. The top ports have a heavier cloth that must seal off those slots. The bottom ones have a thinner grill cloth like cover, that's probably just to keep dust out, but it dampens the ports.  Maybe something a little heavier like electrical tape might be more effective?  I use non hardening modeling clay, like in the picture. It's easily removed if you don't press it in too hard and it structurally damps the enclosure. I removed the cloth from the bottom ports. It made a big difference in deep bass response with my slot-loaded reflex mod.

Seeing how fit and seal effect bass, I think you need a dummy head to measure bass response?  I haven't had a chance to read the methodology, so I'm assuming that.  Most plots have a depression around 2 to 5K shout region and many have a peak around 10K for detail and sparkle. Some of the Sennheisers have a depression instead of a peak and are often characterized as dark.

[JohnR]

I use non hardening modeling clay, like in the picture.

Definitely I think something more solid is needed here. Will try again.

[eclein]

I don't think the slots being covered is going to give you what you want. It looks like covering them just gives you nothing consistent. How about the top, say four slots with and without coverage and then the bottom 4 the same way. I'm totally guessing, I'm no help...LOL....Lol....

[neobop]

The top 4 slots are covered from the inside.

Sealing the phones is definitely a viable alternative. Many of the published mods seal them up. The ones that don't, and use the stock enclosure, all seem to use 1 slot. It's easy enough to get a rough idea by playing with tape or clay on the outside.  I figured you just treat it like a speaker enclosure, bass reflex or sealed. An acoustic suspension enclosure is usually completely stuffed with damping material. A bass reflex usually has just the walls lined with dacron or fiberglass. IMO one thing to avoid is using something that will reduce the size of the enclosure or over-damp internally. Some of the mods use deadening sheets like you put in a car trunk, only thinner.  I didn't try that. I think it's the wrong approach. The plastic is rigid enough and if necessary, you could damp it from the outside rather than killing the sound. I think you can pick your enclosure type and tune it like any loudspeaker. It gets tedious, but you could try it both ways.

Mine have a little too much bass, but I really like it. I think I can add a little more dacron (AcoustaStuff) and get it perfect with the 840 pads.  If this works out I'll probably make little wood pieces to cover the slots and hold them in place with clay.

[neobop]

Sorting through the mods can be a daunting task. I think this one by Bluemonkeyflyer is really helpful:
http://www.head-fi.org/t/452404/just-listened-to-some-fostex-t50rps-today-wow/2640#post_7768186

Here's a summary for this thread:
http://www.head-fi.org/a/fostex-t50rp-modification-summary-links-wiki

Another hugh thread is Orthodynamic Roundup - 1319 pages:
http://www.head-fi.org/t/111193/orthodynamic-roundup/6660

[neobop]

Here's what they look like now.



Still a little crude looking, but I wasn't into spending a lot of time. This was an experiment really. It's a couple of coats of nail polish.  I keep 4 colors around to mark wires.  I don't really care much about that. I want to keep the clay from being easily messed up. If you want them to look great, spend some time and get the clay perfect. Probably wall paint would look better and might hide imperfections.  You could even use black satin finish to match the enclosure.

The more I listen to these, the more I appreciate them.  The planer drivers have that relaxed, effortless sound. Once you get the frequency resp the way you like it's hard to listen to dynamic drivers.  For some reason this seems more so (to me) than loudspeakers. 

I bought some reflex dots at a home improvement, but I don't want to mess with the driver and I'm not sure if I want more treble.  In one of those Head Fi threads I read where one of the guys took them off. On the back of the driver there's a gauze-like cloth and the dot is centered on that.  Anyway, they're in the furniture/ hardware aisle next to casters. They're called felt pads. It's a flat rubber disc that's sticky on one side and has about 1/8" of felt on the other. I got ones 3/4", 19mm diameter. You have to slice off some of the felt - it's too thick. I figure  it would also be good on top of the housing for the headband swivel, inside the enclosure. I haven't done anything there and I figure I'll put a thin layer of clay around the sides and maybe a dot on top.

I think I'm close to having these sound perfect for me. Just a hair more damping inside, and hard wiring the cable or replacing the jack, should be it. I'm glad I got these.  If I got $1K or $2K planers I'd probably be modding them anyway.  If you want, you can get wood cups for $200. IMO the only type of headphone driver that beats this is electrostatic. They're expensive and a PIA with dedicated amps.