[Feilong4]

Found a "broken" set of DT990's and was finally able to do the T30 transplant I've planned a while ago. I originally wanted to transplant them into a DT770, but the DT770 has nubs that don't allow me to push the driver deep enough into the earcup. The T30 driver is a perfect fit in the DT990. With the plastic circle pressed in, the driver is pretty much secured in place. Also originally planned to put a detachable cable system on it but the driver takes too much space for it.

Purpose: For comfort and to preserve the T30 chassis. The forks on the T30 chassis are known to break. Also, for fun.

Recabled the whole thing and put Shure SRH1540 pads on. The other pads I have on hand made them too bright or too distant sounding.

Sound:
Pleasantly surprised with the results with Shure SRH1540 pads. Warm with a bump probably in the mid-bass while slightly rolling off in the sub-bass. There's a tasteful amount of bloom - I like to think I'm the first to complain when there's too much emphasis in the upper bass and mid-bass. Doesn't really sound bloated or murky. Midrange is a bit laid-back but it is to my liking. No sense of graininess or shoutiness. Not also subdued or recessed. I'd say it starts dipping 2 to 3 db from 1 to 2 kHz while probably dipping more from 3-5 kHz - I generally don't like much emphasis in the 3-5 kHz range so I'm liking the response here. I'd say it climbs slowly back up to 9-10 kHz for a bit of sparkle and articulation it adds to the sound. Not sibilant or peaky but does lack air a bit. Overall, a slight v-shape response.

In comparison to having them on the original chassis with Brainwavz hybrid pads, it seems like the sound is more intimate. Soundstage is less wide and imaging seems to be not as precise and clear; it's a bit odd or rather different, but it's not a polarity thing from wiring. The rear port on the DT990 is smaller and has a black bar across the center which definitely affects the width of the soundstage. It's bassier with slightly less sparkle. I think there is a bit more midrange here than on the original chassis with Brainwavz hybrid pads. Not really better or worse but rather different. Using the Brainwavz hybrid pads with the modded DT990, it sounds extremely bright and thin whereas it was pretty much well-balanced on the original chassis.

Conclusion:
I wasn't expecting to like this as much as I do now. Much more comfortable and I don't have to worry about the silver forks snapping when using them. A huge plus is there's more earcup articulation whereas it was none with the original chassis.

 

[Feilong4]

Seems like I'm the latest owner of the HP-500 that's been passing around.



I opened them up and it's a Mylar diaphragm!



The earpads are soft rather than the hard pleather that came on my T50. Stock T50 and stock HP-500 earpads side by side in both pictures. T50 on left, HP-500 on right.



Something kinda interesting. The front baffle of the HP-500 is reflective, whereas on the T50 it's not. T50 on left, HP-500 on right.



Edit: Well, no wonder why the HP-500 fits quite a bit tighter on my head. It has less headband adjustments! Well that and it has more clamping pressure. The Fostex T50 has more headband adjustment - 2 notches lower (11 notches shown on max adjustment on T50, 9 notches shown on max adjustment on HP-500). The notches are on the outside on the T50, inside on the HP-500



Earcup and rear porting.



Left side wiring.



Edit: Another thing I noticed, there's a piece of tape right along the middle on the back of the driver. The may explain the heightened treble response I heard. Because of the glue residue on the tape and around the back of the driver, I assume the tape was put on like this during production.



Magnets



Oh and they have a buzzing problem which I'm not really surprised at this point. Have to cut out my "spacers" that I've drawn a while back for the T50.



I'm using Shure SRH1540 earpads on these. It's a bit hot up top so I cut out a donut from a sheet of felt to mediate that. Seems to help a bit from subjective listening. Will have to measure that when my EARS measuring system arrives.

Edit: Now using the MrSpeakers pads.



Other things I noticed:
- The HP-500 (Mylar) is noticeably more sensitive than the T50 (Kapton). I'm at around 10-11 o'clock with the HP-500 whereas I go 12-1 o'clock on the T50.
- The HP-500's front baffle seems to be a bit smaller in diameter than the T50. A quick measuring got me 3.8125 inches (9.68375 cm) on the HP-500 and 3.9375 inches (10.00125 cm) on the T50. I was able to fit the SRH1540 pads on the HP-500 whereas I could not fit those pads on the T50.
- There are rings around and behind the front baffle of the HP-500. The T50 doesn't have such rings.
- Single cable entry on HP-500 and dual cable entry on the T50 (well, obviously)
- HP-500 has higher clamp than the T50 (though there are many variables that may explain why)
- HP-500 earcup swivel is stiffer (again, many variables)

Sound Impressions:

With stock earpads:
Sounds very neutral. I generally like a more laid-back midrange and upper-midrange - these have just a touch more in the midrange than I'd like with the stock pads but I still like it nonetheless. These sound a bit congested and jumbled during higher volumes though. Like all instruments mushing together.

With MrSpeakers Ether C angled earpads (using on my T50):
The overall response seems to be very similar to the stock earpads. Seemingly neutral though maybe a touch warmer and a bit less in the midrange. I don't get that sense of congestion with higher volumes with these pads. I think I like them with these pads the most.

With Shure SRH1540 earpads:
As mentioned above, it's a bit hot up top without the felt. I'm kinda surprised but it sounds pretty good after just a bit of listening. Definitely warmer than the MrSpeakers Ether C angled earpads. Quite a bit of bloom in the bass or maybe even boomy, but it's a tasteful amount like the HD650 (well, YMMV). Midrange seems to be pushed back the most with these pads.

I'm going to need more listening time to compare the T50 (Kapton) to the HP-500 (Mylar).

 

[GREQ]

Something kinda interesting. The front baffle of the HP-500 is reflective, whereas on the T50 it's not. T50 on left, HP-500 on right.

My RP18 baffles were also dull until I briefly introduced it to chrome polish

 

[Feilong4]

Late night typing. Please excuse typos, grammar mistakes, if I wasn't articulating an idea well enough, etc! Will edit some things later.

I’ve done a bit more listening with my T50 and HP-500 but first and foremost, some background info of the two headphones I have in particular and some factors that may affect my thoughts.

My T50 has flattened damping (again, due to my lack of care) and my HP-500’s damping is still puffy. The “bass-filter” on my T50 has been scrubbed off (did not know what it was until someone mentioned it to me). My HP-500 has a piece of tape right in the center on the driver’s rear; my T50 does not have this. My T50 has different grills on and a piece of speaker cloth right behind the grills, so it might not sound exactly like a “stock” T50 would. My T50’s been recabled - I’m not really a believer of cables making a big difference, but thought I should mention it for those who do believe/have experienced differences. I haven’t changed the cable on my HP-500. My T50 has a looser clamp than my HP-500 does; my T50 also has better/smoother horizontal earcup articulation than my HP-500. I’m using MrSpeakers Ether C angled earpads on both - I have to use the same earpads for both headphones so there’s definitely a longer delay in this side by side comparison. I use “my” a lot here because YMMV, and someone else may very much have varying experiences.

Another factor is that I’ve been using my T50 as my reference and daily driver for the past 8 months or so now. I’m definitely a bit biased towards my T50.


Comparisons:

Fostex T50 (Kapton)

• More forgiving
  
  
• Wider sounding
  
  
• Bass has more thump, warmer, heftier; maybe like +2 or 3 db more in the 100-250 Hz range
  
  
• Midrange seems to be more or less the same quality, vocals are a bit smoother and have just a bit more warmth on the T50
  
  
• Bass extension seems to be equally very good on both
  
  
• Treble is much more smoother and less peaky (I would say that it doesn’t sound peaky at all)

Aiwa HP-500 (Mylar)

• More sharp and a bit tizzy; can’t say the treble sounds clean - maybe grainy is the word I’m looking for?
  
  
• Not as wide sounding, a bit like 'putting both hands a few inches from the rear opening of the T50' kind of width
  
  
• Bass not as hefty, maybe a bit looser sounding?
  
  
• Seems to have a bit more “dynamism” - to me, it means I find myself with my eyes widened more often for good or bad
  
  
• Midrange seems to be more or less the same quality, vocals seem to be just a touch more screechy
  
  
• Better speech intelligibility (possibly due to being sharper up top and emphasizing SSS, THH, SHH, etc sounds)
  
  
• Bass extension seems to be equally very good on both

Other thoughts:
Both are fairly similar. I’ve mentioned that I think the T50 (Kapton, flattened damping, MrSpeakers Ether C Earpads) seem to be brighter from the upper midrange and lower treble. I’m having second thoughts on that the more I listen. I think the sharp treble/upper treble response on the HP-500 may give a sense of a darker or a bit more recession from the upper midrange and lower treble region. The T50 (Kapton) doesn’t have this sharpness in the treble/upper treble so it seems more gradual (perceptually “brighter” to me in the upper midrange and lower treble region because no treble/upper treble peak). I believe the tape used on the HP-500 acts like a reflector which causes the sharpness in the treble. I’m going to get these measured first with the tape on before measuring and listening to them with the tape off.

Conclusion:
My preference? No doubt, my T50 (Kapton). I’m not just saying that because I've put more work into reviving them. It’s warmer and smoother up top, but wider and much more comfortable to wear. I really dislike sharp treble peaks. I think even my DT990 is softer in the treble in comparison to the HP-500, and I think that’s really saying something. However, I do think that can definitely be remedied with a bit of modding - maybe removing the tape and/or a thicker donut felt over the front opening.

 

[MDR30]

Seems like I'm the latest owner of the HP-500 that's been passing around.



I opened them up and it's a Mylar diaphragm!



The earpads are soft rather than the hard pleather that came on my T50. Stock T50 and stock HP-500 earpads side by side in both pictures. T50 on left, HP-500 on right.



Something kinda interesting. The front baffle of the HP-500 is reflective, whereas on the T50 it's not. T50 on left, HP-500 on right.



Earcup and rear porting.



Left side wiring.



Edit: Another thing I noticed, there's a piece of tape right along the middle on the back of the driver. The may explain the heightened treble response I heard. Because of the glue residue on the tape and around the back of the driver, I assume the tape was put on like this during production.



Magnets



Oh and they have a buzzing problem which I'm not really surprised at this point. Have to cut out my "spacers" that I've drawn a while back for the T50.



I'm using Shure SRH1540 earpads on these. It's a bit hot up top so I cut out a donut from a sheet of felt to mediate that. Seems to help a bit from subjective listening. Will have to measure that when my EARS measuring system arrives.

Edit: Now using the MrSpeakers pads.



Other things I noticed:
- The HP-500 (Mylar) is noticeably more sensitive than the T50 (Kapton). I'm at around 10-11 o'clock with the HP-500 whereas I go 12-1 o'clock on the T50.
- The HP-500's front baffle seems to be a bit smaller in diameter than the T50. A quick measuring got me 3.8125 inches (9.68375 cm) on the HP-500 and 3.9375 inches (10.00125 cm) on the T50. I was able to fit the SRH1540 pads on the HP-500 whereas I could not fit those pads on the T50.
- There are rings around and behind the front baffle of the HP-500. The T50 doesn't have such rings.
- Single cable entry on HP-500 and dual cable entry on the T50 (well, obviously)
- HP-500 has higher clamp than the T50 (though there are many variables that may explain why)
- HP-500 earcup swivel is stiffer (again, many variables)

Sound Impressions:

With stock earpads:
Sounds very neutral. I generally like a more laid-back midrange and upper-midrange - these have just a touch more in the midrange than I'd like with the stock pads but I still like it nonetheless. These sound a bit congested and jumbled during higher volumes though. Like all instruments mushing together.

With MrSpeakers Ether C angled earpads (using on my T50):
The overall response seems to be very similar to the stock earpads. Seemingly neutral though maybe a touch warmer and a bit less in the midrange. I don't get that sense of congestion with higher volumes with these pads. I think I like them with these pads the most.

With Shure SRH1540 earpads:
As mentioned above, it's a bit hot up top without the felt. I'm kinda surprised but it sounds pretty good after just a bit of listening. Definitely warmer than the MrSpeakers Ether C angled earpads. Quite a bit of bloom in the bass or maybe even boomy, but it's a tasteful amount like the HD650 (well, YMMV). Midrange seems to be pushed back the most with these pads.

I'm going to need more listening time to compare the T50 (Kapton) to the HP-500 (Mylar).

Good and interesting documentation.

 

[Pilotdog68]

I've got some new-old-stock 50mm TDS-16 drivers that I need to sell.


Info here: https://www.reddit.com/r/AVexchange/comments/8on4sa/wtsusafiio_f9_fiio_q1_kz_zst_oppo_pads_cable/

 

[Feilong4]

Got my EARS measuring unit yesterday. Did a few measurements. Of course, it's not a professional tool but it does give a lot of insight in the sound. The T30 measurements will come at a later time - earpads incoming.

Measurements matched at 300Hz as recommended in the manual. I tried matching at 1000 Hz but both sides became very uneven.

Fostex T20v1 Modded vs Stock


Used with Shure SRH1540 earpads; stock is everything removed with the stock earpads.

It's fairly boomy but otherwise I'm quite proud of it. I quite like it but of course, the modding quest continues. I don't quite notice the peaks at 7 and 8 kHz

Fostex T50v0 Modded vs *Stock


Used with MrSpeakers Ether C Angled earpads.

*Stock - as close to stock as I can get. Some of the internal mods I did are irreversible. They were measured with stock earpads.

Besides a bit of bass-off, a dip at 4 kHz (which I prefer though), and a peak at about 7.7 kHz, I quite like them. Ok, maybe that's putting it lightly; I absolutely love them!

Distortions for both the T20v1 and T50v0 don't look quite right. I'll have to read up on what's going on.

Fostex T50v0 (Kapton) vs Aiwa HP-500 (Mylar)



Seems like the HP-500 rises a lot more quickly than the T50 to about 8kHz. It does seem like the T50 is "brighter" in the upper midrange and lower treble like I initially thought (well, by that I mean from 2-6 kHz). Both hit 8kHz at about the same place; just that the HP-500 rises very quickly to 8kHz which is probably what I experienced when I mentioned that it was peaky/hot sounding. Bass extension is better on the T50 though I'm surprised both roll-off by quite a bit; could definitely be from the compensation used, the rig itself, etc. Again, it's not a professional tool but it does give quite a bit of insight in the sound.

Edit: The donut felt I mentioned in my post above did NOT help at all. In fact, it seems like it made it worse haha!

 

[Shredicus]

Very cool. Any t20v2 in the cards?

 

[Feilong4]

Very cool. Any t20v2 in the cards?

If you mean if I have the T20v2 on hand, I don't unfortunately.

 

[Feilong4]

Fostex T30 measurements (matched at 300Hz @90db, 1/24 oct smoothing applied, default compensation):

Also, pay no mind to the blue cross-hair. It's just the cursor.

 

[GREQ]

At a glance, the T30/DT990 mod seems to be the 'best'.
Good stuff.

How are those brainwavz pads? By the looks of it, they cause a bit of a mid-bass hump?
I've only got some cheap stock knock-offs from eb@y, but that's 99% of my experience with these pads with almost any headphone.

 

[Feilong4]

At a glance, the T30/DT990 mod seems to be the 'best'.
Good stuff.

How are those brainwavz pads? By the looks of it, they cause a bit of a mid-bass hump?
I've only got some cheap stock knock-offs from eb@y, but that's 99% of my experience with these pads with almost any headphone.

It does seem like it. I do think the treble is a bit too much. I much prefer the treble response with the Brainwavz hybrid pads.

The brainwavz pads are pretty good. Very comfortable. Well, it seems more like they're causing the midrange to recess rather than creating a mid-bass hump. The driver sits further from the ear, more so than the SRH1540 pads I used with the DT990 Pro mod. There is a midrange imbalance with the DT990 mod which I think may be caused by the excess cabling I left in the earcup (in case if I didn't want to go through with it and use the cable for another headphone).

As of right now, I just EQ up the midrange of the T30 with the Brainwavz hybrid pads (+3db @900Hz, +3db @1kHz, +3db @1.5kHz, and +2.5db @2kHz). I think due to the much bigger opening of the T30's rear port, it's a much wider soundstage than with the DT990 Pro chassis.

 

[takato14]

My measurements of the stock T30 are way different.

Really nice response from these aside from the 3kHz peak. They're like a "fixed" T50 in many ways but ultimately lack the smooth treble response of the T50, in exchange for better resolution, less distortion, and more slam/dynamic range. I have yet to find a configuration I like for these and I think part of that has to do with how crappy the stock enclosure is -- not at all surprised that the DT990 housing does these a few favors. Probably gonna sneak these into the extra SS-100 housing I have at some point...

 

[Feilong4]

My measurements of the stock T30 are way different.


Really nice response from these aside from the 3kHz peak. They're like a "fixed" T50 in many ways but ultimately lack the smooth treble response of the T50, in exchange for better resolution, less distortion, and more slam/dynamic range. I have yet to find a configuration I like for these and I think part of that has to do with how ****ty the stock enclosure is -- not at all surprised that the DT990 housing does these a few favors. Probably gonna sneak these into the extra SS-100 housing I have at some point...

Yeah, I now know that I did not "seal them properly". Well at least the only way I can get them to look "right" is to push the earcups onto the silicone ears to "properly" seal them. Even then, I question how accurate that method would be since the headphone doesn't have that much clamping pressure.

As an example, I measured the Fostex T10 with pushing the earpads onto the silicone ears and with no pushing. In this case, however, the T10 does clamp and seal very well my ears so in this case, I would say that blue and red lines are more accurate in my experience.



The T10 earpads have some cushion or some "give" to them so they compress and seal better than the T30 earpads which are just hard pieces of pleather or some material. The earpads on the T30 do not compress nor do they seal well on my ears, so I would argue that my measurements of the T30 reflects more accurately to my experience.

How did you seal the T30 and your SS-100 when you measure it? Did you push the earcups onto your measuring rig? Is it a flat plate coupler? What is the compensation and did you use any smoothing? As for the MiniDSP Ears that I've got, I didn't push the earcups in and I just used the default L/R compensation file provided by MiniDSP. I did 1/24 oct smoothing on the T30 measurements, and 1/24 oct and "psychoacoustics" smoothing for the T50.

Now, I just have them with the Brainwavz hybrid pads (non-angled) with the stock chassis and EQ from there. No horizontal earcup articulation but the earpads do seal over my ears nicely. No mods besides the earpads. I'm a bit burned out from modding various headphones, so I EQ for the most part now.

 

[matarua]

I do find it incredible how there's such a market for 'cables' that do nothing - yet all this talk of pads that do heaps - surely there's a market for pad sound altering systems - just an idea