CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Headphone Measurements => Topic started by: Marvey on December 09, 2011, 07:07:15 PM
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Fostex T50RP Stock Frequency Response and CSD Waterfall Plots
CSDs very clean. Check out Paradox (http://www.changstar.com/index.php/topic,41.0.html) mods which clean up the treble.
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It's strange that these measure so well stock because I thought they sounded pretty resonant. But maybe it's because it's not coming from the driver as much as the enclosure, which doesn't show up in these plots as much? Not sure why that would be though...
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It's strange that these measure so well stock because I thought they sounded pretty resonant. But maybe it's because it's not coming from the driver as much as the enclosure, which doesn't show up in these plots as much? Not sure why that would be though...
It's the wavey wave patterns at 1k. Definitely an enclosure issue. Compare with the Paradox. Although it's hard to see because I need to extend more to 6ms.
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It seems like all your plots show broad, smooth looking ringing starting at about 1khz. I figured it was more the testing method than the headphone, and your plots are meant for higher frequencies than that.
But maybe what's happening is that the T50rp is a much cleaner driver to begin with than almost all other drivers, and the stock driver is actually fairly nicely damped, so all the added junk here, while not much compared to other phones, is coming from the cups, which sounds different than the driver ringing other phones have as well?
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i think the problem is mainly the pads. they're so thin it touches your ears and has no seal whatsoever. just changing them alone will be an improvement with the fostex. they actually sound nice with just pad replacement alone and very listenable. yea there is still issues within the cup region but will be much less noticeable due to driver being farther from the ears. i actually listened to mine for while and liked it when i just swap the pads with pair of akg 240 pads alone and stuffed them a little before i even bothered opening them up.
i wonder how the fostex driver will do in a completely open design cup. i had diagrams and schematics drawn out before from all the ideas i had written down that i used studying many open designs and how driver would react using my imagination,picturing the soundwaves in my head backfiring and reflecting back inside the earcup. thing is i don't have any wood working skills or metal working skills. all i know how to do is solder and drill holes. basic stuff basically, so all i can do is use my imagination on ''what it can be.'' or ''possibilities'' and so forth.
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So can someone describe the differences in sound between say... fa-003 pads vs shure 840 pads vs akg pads on these cans? Measurements using different pads and the cans/enclosure being barebones stock would be awesome!
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Do you mean something like this ? : http://www.head-fi.org/t/618659/fostex-t50rp-incremental-mods-and-measurements
So can someone describe the differences in sound between say... fa-003 pads vs shure 840 pads vs akg pads on these cans? Measurements using different pads and the cans/enclosure being barebones stock would be awesome!
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Thats a great link. Thanks! but maybe some csd plots would be nice too along with some listening notes. It doesn't have to be as detailed as that thread with all the mods. The more important thing would be just listening notes/impressions of all the pads compared on the cans without any other mods done to them at all. A basic beginners guide so to speak before getting into the internal modding.
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you can start reading this thread then :P
http://www.head-fi.org/t/452404/just-listened-to-some-fostex-t50rps-today-wow
i think most people who want to mod the t50rp started reading here, with an exception to the wiki made
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I think only purrin can do a csd plot of all the pads compared on a stock fostex :)
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I'm listening to a stock t50rp now out of a budget fiio e10DAC to O2 setup and I am actually finding that the biggest thing wrong with this stock config is the boomy upper bass. Its a little fatiguing but I have a feeling that when modded these will sound great. If this upper bass is tamed enough to let the highs come through better, these will be awesome cans since what i hear from the high frequency quality now is awesome!
Oh and except for the upper bass/lower mids bloat, the mids are nice and big sounding.
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I tried them, nothing really sounded bad but I wasn't convinced either. I might consider buying it again for some changes...
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The more I listen to the stock T50RPs, the less happy I am with them. I was positive at first, but they have the sound of speakers in a room with terrible acoustics to me. It sounds like the high-end is completely shaved off (lacks the cleanness in the highs that I'm used to hearing from the SR225i), but I do like the mids of the stock T50RP.
I've heard headphones with similar acoustic properties of the stock T50RP. The weird thing about the T50RP is that I can hear cleanness in the mids, whereas those cheap headphone alternatives tend to just sound smeared and imprecise overall. The problem is that the lack of cleanness in the highs and the weird things happening in the lows are becoming more and more distracting to me.
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I believe they made some slight changes to the T50RP somewhere during the Fall 2011-Spring 2012 window, correct? I remember the first pair I got sounded horrible. It had some redeeming qualities but was mostly weirdness all around. The newer version didn't offend my ears nearly as much. I actually found a good bit to like about it! I know the material behind the driver was slightly changed, as was the color on the metal headband rods. It was probably the different color on the headband rods that contributed to the change.
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It was probably the different color on the headband rods that contributed to the change.
LOL. Eleysian, you should think of the T50rp as a headphone you pulled off the production block before it was finished. They stuck the drivers in there, but they hadn't put the damping in the cups yet.
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hans: I received my T50RPs in July, so unless they were a set that's been sitting on the stockroom for awhile, I'd imagine they are a relatively recent production run.
RD: Does the dampening help significantly with that weird echo (it's not really an echo, but it just sounds way too boomy in a bad way, like when virtualization audio 3D mode is turned way too high)? I like the mids but I wish there was more crispness in the highs and a tighter lower end. Can mods really make that much of a difference, or do the mods only help with the weird echo?
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If you heard my T50rp's and a stock pair blindfolded you would think they were completely different headphones. Damping is incredibly important with orthos, especially a closed ortho and even more especially a closed ortho with a driver like the T50rp which really needs to be slapped into submission. I can't emphasize the idea enough that the stock T50rp is an unfinished headphone. Think of it as you would think of an amp that is missing some vital peice. Or a Porche if you put Prius suspension on it. It would be hard to judge the Porche's handling potential with that crappy suspension.
The echo you're hearing is directly caused by the lack of damping.
But damping doesn't just reduce cup resonance. It changes the way the driver behaves, changes the speed and frequency response. A well damped T50rp's driver is operating differently than a stock T50rp's driver. Regardless of cup resonance.
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Can mods really make that much of a difference, or do the mods only help with the weird echo?
Yes, mods can make a dramatic difference. And while I could never get my pair up to the level of LFF's Paradox, even basic mods can make a world of difference.
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hans: I received my T50RPs in July, so unless they were a set that's been sitting on the stockroom for awhile, I'd imagine they are a relatively recent production run.
RD: Does the dampening help significantly with that weird echo (it's not really an echo, but it just sounds way too boomy in a bad way, like when virtualization audio 3D mode is turned way too high)? I like the mids but I wish there was more crispness in the highs and a tighter lower end. Can mods really make that much of a difference, or do the mods only help with the weird echo?
just throw in some fiberglass(r-19 value is fine) or mineral wool(roxual is good stuff) and polyfill/fiberfill and see for yourself. pads make very nice difference too cause how it couples to the ear. i liked using akg 240 pads and the shure 840 pads. the felt/cloth on the shure 840 helps good amount as well but i found the 240 foam discs found in the 240 studios work great too. it fit inside the shure pads fine. the pads alone can make a nice change cause how horrible the stock pads are and how close the drivers are to the ears.
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I take it this is the version with more porous damping thingy and brushed headband rods right? purrin?
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It's Paradox serial #1.
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Really? So this isn't the stock t50rp's at all but Luis' original paradox?
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Really? So this isn't the stock t50rp's at all but Luis' original paradox?
It's the stock T50RP that was later modded into the Paradox
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ahoy There
fellow pirates :)p7
This is my first proper post so I don't really feel worthy of calling myself a pirate yet. I found this awesome place about a week ago on IF and have been reading lots of posts around here since, good job purrin and crew! -absolutely loving it!!
Anyway, I just wanted to stop by and say that you have inspired me to do my next project (well after the V-Moda M-100... and SoundMAGIC HP100 anyway). I don't own any Orthodynamics yet and decided to start with the T50rp, I am then planning to get both the 'Mad Dog' & 'Paradox' mods and will review them all together for my blog (http://noblehifi.blogspot.co.uk/). It will just be a subjective review, although I would like to link to the FR/CSD charts here in the review/s, would that be ok purrin?
Thanks guys and have a great weekend!! headbang
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ahoy There fellow pirates :)p7
This is my first proper post so I don't really feel worthy of calling myself a pirate yet. I found this awesome place about a week ago on IF and have been reading lots of posts around here since, good job purrin and crew! -absolutely loving it!!
Anyway, I just wanted to stop by and say that you have inspired me to do my next project (well after the V-Moda M-100... and SoundMAGIC HP100 anyway). I don't own any Orthodynamics yet and decided to start with the T50rp, I am then planning to get both the 'Mad Dog' & 'Paradox' mods and will review them all together for my blog (http://noblehifi.blogspot.co.uk/). It will just be a subjective review, although I would like to link to the FR/CSD charts here in the review/s, would that be ok purrin?
Thanks guys and have a great weekend!! headbang
Since purrin already has Paradox measurements (though, maybe 2nd measurements would be nice to compare?), maybe you could send the Mad Dogs in for measurements.
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I thought I saw measurements for the Mad Dog around here somewhere too actually. If you would like them purrin please let me know asap, I might be able to get them sent straight to you (before they come to me). Since I'm in the UK it would be costly to send them out of the country again after I get them. Every time they come into the UK I get charged huge customs fees :(.
My main reason for mentioning the three headphones was to thank purrin for the great graphs he already has and see if he minds me linking people here from my blog. Actually does that work? Or are these pages private?
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I have no measurements of the current MadDog. I know Dan has improved them through successive iterations. They sounded pretty good at the Village meet, and I think they sounded even more neutral at H3.
I'm not sure if it's worth shipping them all the way from the UK!
Free feel to link here knowing that six people in the world do seem to really hate us.
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Ah, yeah...being in the UK changes things.
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Thanks purrin! Hey how can anyone hate you guys, you're frickin adorable! :)p6
As for the MadDogs, I only ordered them this morning. Would you like me to try and get them shipped to you so can run the tests? Although I'm now sensing a logistical nightmare with shipping costs. Anyway let me know and I will see what I can do. :)p1 :)p3 (sorry, just trying the Smiley's, they're ace).
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I tried some stock t50rp today. I don't know of anything else that has that level of performance for such a low price. I did notice that some instruments sounded quite thin (Coltrane's saxophone on Giant Steps for example). Looking at the CSD I can't really see a reason for it. Is this something that modding could fix? I figured that the lack of damping in the drivers or the terrible stock pads may be causing this effect.
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The stock T50RP is really best viewed as an incomplete headphone. Modding will definitely improve its performance, but it takes time to experiment and get a handle on what effects you can achieve. Which is part of the appeal of DIY.
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Note that many mods don't do too much to the FR (well, some smoothing out and extra subbass), both MrSpeaker's (adds some midbass) and Paradox. What they vastly improve are the resonances and fit.
For example, this is the latest precise Paradox EQ.
If it doesn't look very similar to "inverted" T50RP stock response, I don't know what does.
However, since they're extremely clean except perhaps slightly midbass, the equalization doesn't mess them up in the slightest.
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The stock T50RP is really best viewed as an incomplete headphone. Modding will definitely improve its performance, but it takes time to experiment and get a handle on what effects you can achieve. Which is part of the appeal of DIY.
Exactly !
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Just wanted to share these T50RP measurements:
Frequency Response:
(http://www.changstar.com/index.php?action=dlattach;topic=62.0;attach=6224;image)
Distortion Right:
(http://www.changstar.com/index.php?action=dlattach;topic=62.0;attach=6226;image)
Distortion Left:
(http://www.changstar.com/index.php?action=dlattach;topic=62.0;attach=6228;image)
CSD Right:
(http://www.changstar.com/index.php?action=dlattach;topic=62.0;attach=6230;image)
CSD Left:
(http://www.changstar.com/index.php?action=dlattach;topic=62.0;attach=6232;image)
T50RP vs HD600:
(http://www.changstar.com/index.php?action=dlattach;topic=62.0;attach=6234;image)
In stock form, I think the T50RP relative dip between 2 kHz up to 5 kHz is what makes it sound a bit odd to me.
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Sheesh, that's a big hunk of missing information between 2 and 4.5kHz.
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Just wanted to share these T50RP measurements:
Thanks for sharing... let me share something with you :D
I measured the same 'chunk' and am annoyed with the lack of highs extension.
15dB down around 3.5kHz !
They drop off quickly above 10kHz and at 20kHz they are already 20dB down !
Indeed it is what makes them sound 'weird' when compared to 'flatter' headphones.
The lack of highs extension is what bothers me most when compared to others.
(http://i837.photobucket.com/albums/zz296/solderdude/T50RP_zps0d52a5ff.png) (http://s837.photobucket.com/user/solderdude/media/T50RP_zps0d52a5ff.png.html)
Purple is stock T50RP (not entirely stock it has the familiar mechanical mods) NO fake Pinna.
Blue is what it can be (but not through mechanical mods)
When you measure the same headphone with the BMF kit you will find the dip around 3.5kHz is gone.
I think it is because the mic is closer to the driver and the Pinna alters the FR.
The chunk gets smaller if you use a fake Pinna around the microphone as well (I made one of malleable eraser).
When sweeping it with a tone you will find that the 'dip' isn't 15dB but smaller (about what it measures with a fake Pinna)
The dip seems really there and when compensated as the blue line it sounds incredible, nothing like a T50RP
It is my go-to headphone (the blue lined one)
B.T.W.
I REALLY dig the comparative plots you often make, with 'well known' headphones, it shows in a more direct way what to expect.
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Welcome mate! and thanks for the heads up on the mod improvements :)p5
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A lot of BMF's mods had those paper reflectors in there which I always felt made the treble feel weird and papery (if you'll excuse the pun).
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World's simplest mod to remove the ~1khz ringing:
Step 1: Fold up two nose tissues into two squares.
Step 2: Place them in the cups.
The T50RP is so utterly lacking in damping that literally anything makes it better. I find this to keep the FR and response exactly the same, except it gets rid of the ringing at 1khz. I modded only one of the ears to check what it did, and the difference is actually astonishing. The unmodded one is so strident, and the modded one is so...normal. It kept everything the same except that 1khz ringing, and now it's a decently respectable can.
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For anyone who has disassembled the driver before, which parts of the diaphragm are able to move freely? (refer to below image)
http://farm5.static.flickr.com/4066/4517202697_1769828e23_b.jpg
Would leaving the T50RP "burning-in" overnight (playing a 30Hz sine wave at high volume, for example) possibly help loosen up any moving parts (based on above) or is it likely unneccesary?
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Only the part within the yellow square 'flexes' up an down.
Nothing 'moves' in the sense that a piston in a cylinder moves kind of way.
At least it shouldn't....
Don't know if the membrane needs to be 'burnt in'.
In the 3 ones I had from new I never noticed much difference but others may have opposite experiences.
The ones I have (had) never stayed 'stock' for long. 8)
Never modified the driver though only 'motivate' it to do things in a different way and damp it externally which worked for me.