Fostex T50RP Incremental Mods and Measurements
May 3, 2013 at 4:05 PM Post #511 of 2,832
Oh I will definitely post my impressions of the pads.
 
The difference from the stiff craft felt on the back of the drivers is a good one as well. It definitely made them quicker, more detailed, and more up-front sounding. Before this mod I was always tempted to crank the volume up higher. Now they definitely sound more lively and I no longer have the constant desire to turn the volume up higher. Maybe with the alpha pads I'll finally like them as much, or maybe more than my Q701. Right now it's already pretty close, but a bigger, wider soundstage may seal the deal.
 
Of course these don't sound anything like the Q701, please don't anybody take that last paragraph as me saying they sound the same. I have just always, so far prefered the Q701 over these modded T50rp's. These are sounding better all the time and are growing on me now though. 
 
Quote:
Yeah, I've seen a lot of positive reviews about them (isolation, soundstage, and imaging). I'm definitely interested in getting some, I'm not too concerned with the FR on the high end anyway, it's not like there's ever been a headphone that ISN'T sawtoothed up top. You should definitely comment on your findings with the pads
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May 3, 2013 at 5:02 PM Post #512 of 2,832
I had a similar issue with volume. I was only using cMoy amp and couldn't get to a satisfying listening volume without extra noise or distortion. After trying different amps and DACs, I have noticed that the T50RP's change dramatically with better setups. Granted I'm new to this whole amp-DAC game and I understand that there isn't anything incredible about the cMoy but I don't find much change in sound when playing my Grados through an iPod/cMoy setup vs my Maverick D1. The Fostex though... Incredible difference. Much warmer and a lot more detail in the mids.

Does anyone have a particular setup that they prefer with their T50RP's over others?
 
May 3, 2013 at 11:52 PM Post #513 of 2,832
Quote:
I probably could set one up. I have a Behringer measurement mic that I used to use for tuning my home theater system. I'm not sure if it would work with my current laptop though. 
 
Anyway, people on the Mad Dog thread speak highly of the Alpha pads. Most, if not all, seem to think they are better than the 840 pads. 

If you get the Behringer mic to work well please let me know. 
 
I have a ECM8000 and a MIC800 combo setup with Room EQ Wiz and I am unable to get reliable measurements.
 
I calibrated my soundcard and used a general calibration file for the mic and I was still unable to replicate measurements that even come close to what my LCD-2s should look like according to the graph that came in the box. 
 
I'm not 100% sure on this but I think this type of condenser mic is mainly used for room acoustics, not so much close up headphone measurements. 
 
May 3, 2013 at 11:56 PM Post #514 of 2,832
Quote:
If you get the Behringer mic to work well please let me know. 
 
I have a ECM8000 and a MIC800 combo setup with Room EQ Wiz and I am unable to get reliable measurements.
 
I calibrated my soundcard and used a general calibration file for the mic and I was still unable to replicate measurements that even come close to what my LCD-2s should look like according to the graph that came in the box. 
 
I'm not 100% sure on this but I think this type of condenser mic is mainly used for room acoustics, not so much close up headphone measurements. 

ECM8000 sounds familiar. I doubt I'll ever try and set it up again though. I'm past the point of measuring. I tune everything by ear these days. I'm hoping to put the Alpha pads on, and line the inside of the cups with felt and then be done messing around.
 
May 4, 2013 at 12:50 PM Post #515 of 2,832
Quote:
If you get the Behringer mic to work well please let me know. 
 
I have a ECM8000 and a MIC800 combo setup with Room EQ Wiz and I am unable to get reliable measurements.
 
I calibrated my soundcard and used a general calibration file for the mic and I was still unable to replicate measurements that even come close to what my LCD-2s should look like according to the graph that came in the box. 
 
I'm not 100% sure on this but I think this type of condenser mic is mainly used for room acoustics, not so much close up headphone measurements. 

I assume you have phantom power supplied by your sound card. Is this correct?  I don't know how accurate the generic calibration file is but your measurements should be "relative" to your other measured headphones. Take measurements of your stock T50RP before you make any mods (and your LCD2) and use this as your comparison baseline. You can compare your measurements to others' such as Tyll and purrin. Try to duplicate the headphone placement, clamping force, sweep level, etc. for more accurate comparisons, within and between measurement sessions.
 
How did you mount the mic? AFAIK, the mic needs to be mounted "facing" the driver. You need a complete seal around the ear pads or you get no bass. This makes it impossible to build a jig to place the headphones on, like a headphone stand, with a hole in the center of one side for the mic probe. BTW, The ECM8000 is recommended by REW, IIFC, but it's too long for this application. 
 
Another approach you could try is to use John Conover's method of a single board with a hole in the center, but I'd modify it :)  
 
John Conover's Panasonic WM-61A instructions
 
John Conover's measurement jig
 
 
I would not use an artificial ear canal. Instead, I'd mount the mic probe flush with the board. This might work:
 
1. Cut a "measurement baffle" larger than the headphone and cover it with Paxmate or Silverstone.
2. Drill a hole in the center, just large enough for the EMC8000 probe.
3. Build a wooden "cradle" to support the "base" of the ECM8000 so it can be oriented perpendicular to the Paxmate covered measurement baffle. 
4. Tape around the back of the measurement baffle, once the probe is inserted, to prevent any leaking.
5. I think I'd build the cradle and board so the microphone is stood on its end, in the cradle, with the mic pointed straight up.
6. Position the Paxmate covered measurement baffle horizontal to the base with the Paxmate side facing up. This will allow the headphone to sit face down on top of the Paxmate measurement baffle. I think this will provide even distribution of the headphone's weight for a more uniform seal.
7. Unscrew one side of the headphone, position it on the measurement baffle, and use large rubber bands to hold the headphone in place. I think it will be important to use identical rubber bands and replace them if they weaken, resulting in diminishing clamping force and measurement variability.
 
I think I'll try to build this for my factory calibrated Galaxy CM-140 Checkmate SPL meter. It did not work at all on a styrofoam dummy head because I could not get a good seal.
 
If building a DIY Phantom Power Supply, I recommend solderdude's design at Reply #101. It's cheaper to build and much quieter than the other design I've been using.
 
May 4, 2013 at 1:44 PM Post #516 of 2,832
The Alpha pads are on!!! So far so good, more to come later.
 
May 4, 2013 at 1:55 PM Post #517 of 2,832
Quote:
The Alpha pads are on!!! So far so good, more to come later.


As an informational experiment, could you turn the phones around so the pad angle is reversed and let me know if you hear a difference?
 
May 4, 2013 at 2:15 PM Post #518 of 2,832
They are severely angled. It's an interesting request, but the severe angle makes the soundstage sound as if the music is coming from behind, instead of in front. The very aggressive angle really adds both depth and width to the soundstage when worn correctly. 
 
The alpha pads are angled so much that it pretty much bottoms out the swivel hinge thingamajig. 
Quote:
As an informational experiment, could you turn the phones around so the pad angle is reversed and let me know if you hear a difference?

 
May 4, 2013 at 2:34 PM Post #519 of 2,832
Quote:
They are severely angled. It's an interesting request, but the severe angle makes the soundstage sound as if the music is coming from behind, instead of in front. The very aggressive angle really adds both depth and width to the soundstage when worn correctly. 
 
The alpha pads are angled so much that it pretty much bottoms out the swivel hinge thingamajig. 


Thanks. I was interested in how much the soundstage actually changes. This is a little more confirmation on just how critical the driver to ear placement is on these phones.
 
May 4, 2013 at 6:21 PM Post #520 of 2,832
Well ive been listening and retuning all afternoon. MrSpeakers assumption was correct when he PM'ed me to tell me to expect more bass. Going from the 840 pads to the Alpha pads increased the bass quite a bit. Yesterday i had them tuned pretty well with nice quick impactful bass. After the pad swap the bass was bloated and loose again. I added another cotton ball per side, opened up the baffle vent completely, and put a layer of adhesive felt on the ear side of the baffle around the driver. I then also tried changing the size of the outer bass port, and eventually uncovered the outside vents completely. I only got to listen to it for a couple minutes like this then it was time for dinner. With the outside open, just the stock felt, the bass seemed big, but at the same time seemed under control. I will test more and report back. This is getting fun and interesting.
 
May 4, 2013 at 11:35 PM Post #521 of 2,832
These things are really sounding good. Comfort with the Alpha pads is also very good. I really have no complaints with what I am hearing right now.
 
Bass is tight, well extended, textured and definitely not lacking. Quick enough for rock and metal, but big enough for dubstep. 
 
Mids are lush, smooth, and clear, yet very detailed. 
 
Top end is also smooth, clear, very detailed, and very well extended. Never harsh or sibilant, but I wouldn't call it dark either. Present, but smooth. 
 
Reminds me of a better balanced HD650. 
 
May 5, 2013 at 12:00 AM Post #522 of 2,832
I would like thank BMF for this amazing mod as I have absolutely been floored since applying it to my t50rp's.  I'm still lost for words, but let me put it the simpliest way I can.... after listening to it for past how many days constantly.... I have been on the fence of selling off every other single piece of headphone gear I have.  
 
I can't wait to fine tune these with a measurement kit.  I have applied the DBV mod on one pair of T50rp's and the Rock wool mod on another set.  I will post impressions in a few days...if I ever get to it instead of just blissfully enjoying it in a zombie like trance. 
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Now I am excited about building the sunrise II amp as per his recommendation to pair with the t50rp.  Been constantly selling off excess "fluff" gear just to raise the funds for it.
 
Been wanting to recable the t50rp's but deadly scared that it will mess up the harmony it has right now.  Always have preffered a dual entry than a single entry.
 
used t50rp's with shure 840 pads .... 80 bucks
modding materials.....20 bucks
old shoulder strap pad off an old laptop messenger bad .... free
scrunchies at dollar tree.... 1 dollar
 
audio bliss achieved at a level that thousands of dollars worth of other audio gear has failed...priceless
 
 

 
May 5, 2013 at 12:10 AM Post #523 of 2,832
Quote:
These things are really sounding good. Comfort with the Alpha pads is also very good. I really have no complaints with what I am hearing right now.
 
Bass is tight, well extended, textured and definitely not lacking. Quick enough for rock and metal, but big enough for dubstep. 
 
Mids are lush, smooth, and clear, yet very detailed. 
 
Top end is also smooth, clear, very detailed, and very well extended. Never harsh or sibilant, but I wouldn't call it dark either. Present, but smooth. 
 
Reminds me of a better balanced HD650. 

Damn you... now I really want some 
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May 5, 2013 at 10:20 AM Post #524 of 2,832
I think I might have to add a treble reflector. Last night they seemed bright enough, but right now they sound dark. I'm going to give it a day or two first before I make any more changes though. 
 
May 5, 2013 at 1:01 PM Post #525 of 2,832
has anyone had any experience in recabling the t50rp?  Did it change the sound much?
 

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