[Philimon]

So, this is YH100 (with cups) with a layer of micropore tape over rear of driver.

A pattern Ive noticed in the YH series is that dense materials too near the back of the driver (like micropore or even some denser felts) result in higher distortion across the board. Subjectively, I find dense damping materials too close to rear of driver equate to less clarity / less dark background (to borrow an analogy: compare to differences in black levels on different televisions; or looks "washed out" to borrow a phrasing from khbaur). ... I think this is result of "reflection" (duh?).

2kHz resonance doesn't seem to have improved over stock measurements. It may appear it is an improvement but the relative amplitude at 2kHz is lower on "micropore with cups) in comparison to "stock". Hmmm, signs of potential to improve resonance like in YH2 or YH1 are not so apparent.. YH100's status as as the problem child in the YH series appears to be true. That's my newb assessment of the measurements anyway.

If mods can't improve much, I've experienced that focused EQ can effectively mitigate painful resonances by reducing the amplitude at those specific problematic frequencies making the headphone fatigue free and still sound natural (enough for my ears anyway).

edit: Next I will try regular damping mods.

 

[Philimon]

Awesome Yamaha vintage ortho compendium thread started on that other friendly forum (im not going to say the name as I just got off tempban probation). Anyone willing to lend the OP a YH1000?

Ill be sending a YH100, YH1, and YH2. What’s then needed are some YHD, anybody? Modded Yams would be welcomed.

 

[Philimon]

I ordered some Beats Solo pads to try with my YH1 (or YH100).
https://www.amazon.com/dp/B09G9XTTD9?psc=1&smid=ABQ9LCJ4M7ISO&ref_=chk_typ_imgToDp

Im not sure how they might improve the sound in any single way but I wanted to try. Biggest reason I want to try is because maybe they hold a key to solving some resonance issues that Im having trouble addressing on YH100. See the Shipibo Grado pads before and after CSD for an example of miracle cure for 2kHz resonance. It could be a huge break through I hope for Yamaha mods. The challenge then would be to balance with damping mods but likely would need a combination of mods and EQ.

I also ordered SAE certified felt. Better consistency and options for specific densities.

The felt and pads are cheap like $10 each so no big deal. Im not investing too much money or time. Ive only tried a few other mods with YH100 mostly at the extremes of underdamped or overdamped and each still ends up with some 2kHz resonance. A middle ground (basically stock levels of acoustic impedance) with EQ will probably be best (atleast with stock enclosure and stock pads*).

*fingers crossed that I find khbaur’s driver transplanted yh100 unfatiguing

 

[Philimon]

YH-100s assemble!!!

khbaur’s driver transplanted YH100 is really nice. Well done! Measurements and comparisons later.

 

[Philimon]

@khbaur330162 's YH100 first impressions:

- khbaur's YH100 is much less fatiguing than stock YH100. This is the best part of this mod. Less brash, much more natural.

- does not have that painful upper mids glare that requires careful EQ. Compare to stock CSD​

- the highs peak on khbaur's has seemed to have shifted upwards a little bit vs stock putting it in a less sensitive area (from 8kHz to 10kHz).​

- resonances shifting upwards follows with higher acoustic impedance damping.​

- still think I would personally use a little eq either way since the highs peak is still a little strong just less annoying​

- The dip around 400Hz does make vocals sound a little nasally / hollow. Reducing 2kHz with Loki+ tone control improves satisfactorily.
- Don't know how much resonance is mitigated by the different earpads. I'm going to try some padrolling and comparing CSDs. Pics later.
- The circumaural earpads do a huge favor for YH100's soundstage and making the headphones sound more normal / natural. The stock pads also obscure like 30% of the driver's surface where khbaur's does not at all.
- The pads cavity is much larger than stock which I bet adds to the weight of the bass due to slower decay or reverb. Philimon likey. At first, in comparison to stock, I thought khbaur's YH100 bass was a little bloomy, but now I I've come around. Stock YH100 bass is just a little on the light side which is how I'd feel when comparing Yamaha bass to any adequately equipped with bass headphones (i am basshead).
- This cheap Sony host is quiet and solid. Feels more substantial and more comfy (especially when you factor in circumaural vs supraaural) over stock.

---------------------------
Will do a/b comparison to YH100 stock and YH1 later. If I were better at EQ I'd try to make each headphone's frequency response match as close as possible so I'd be comparing technical aspects rather than tone. Will be doing some eq matching anyway, because I can't really enjoy any Yamaha without EQ anyway (except maybe YH2). I prefer warm and dark headphones and am picky like that to where I typically wont even use a headphone if its not laidback enough.
--------------------------
edit: The longer I listen the more I want to copy this mod for myself. Thanks khbaur!
edit2: I'm going to discuss more on technical aspects like imaging (delineation, depth) etc (transients, macrodynamics) for when I do a/b comparison. I have to a/b with notes to be sure of more nuanced stuff like that. My memory sucks but I am pretty confident this Yamaha rules.

 

[khbaur330162]

Ok, so @Philimon kindly asked that I do a quick writeup of the mods performed to these specific YH-100's. Here goes:



1. Transplanted YH-100 drivers into Sony DR-ZX701ip housing. (Epoxy putty was used to cement drivers in place as well as seal all openings between back and front waves, i.e. baffle vents)

2. Akasa paxmate lines driver housing walls to reduce reflections.

3. Twaron Angel hair fills driver housings to diffuse backwave and reduce cavernous sound. It might also slightly damp drivers, but not enough to smooth out the FR and reduce 400Hz droop.

4. Chinese lambskin pads swapped for stock. These were made for the MDR-ZX700 and are fairly cheap on Aliexpress.

5. I lined the baffle fronts with Paxmate to try and reduce sibilance. I removed most of it, but some remains. How much it affects sound? Probably not much at all.

6. Few chunks of Sorbothane stuck onto baffle rears to absorb resonances/vibrations in baffle plastic. Probably not needed.

6. 8 core, Silver plated OCC Copper Litz braided cable replaced stock. This probably has something to do with Philimon's impression of increased bass impact, imho.

7. There is NO damping applied to rears or fronts of drivers. You could add slight damping and actually boost 400Hz relative to everything else... generally smoother FR, but it also adds slightly to sibilance so I have opted to keep drivers undamped with bass roll off and all. I don't care about measurements that much but it does help me tune, it's about my experience using them, mostly.

-edit- 8. I lubricated the hinges on DR-ZX701ip housing. There are hinges that account for the swivel of earcups (forward back, not up and down) which have o-rings inside which squeak off the plastic, super annoying. I bought some synthetic oil off Amazon, dripped a couple drops into the hinges and worked them in with a few rotations back and forth, it basically oils itself, you don't have to take the headphones apart at all to do this.



For posterity, some pictures of similar mods. I don't have YH-100's in hand and never took the pertinent pictures needed, but my YH-1's are almost identical in build, just different cable and drivers, basically.




YH-1 driver installed in DR-ZX701ip

Twaron angel hair fills driver housings

Akasa Paxmate lines housing walls. (Note the bass port is left unobstructed)

YH-100 driver installed in baffle. The reflexive damping or whatever you call it has since been removed due to smearing of the image, but this photo shows Sorbothane installed and epoxy putty. The putty looks a little overdone in this one, but I had issues of previous builds with rolled off bass due to not properly sealing everything so I just wanted to make sure this one was good. Also, the epoxy putty adds to the weight of the headphones. Stock DR-ZX701ip's feel light weight and cheap. Adding heavy ortho drivers and some epoxy putty really adds to their heft and more premium feeling, imho.

These are my EARS measurements of YH-100's as they are currently configured (for comparison to @Philimon 's). Note the more severe 400Hz droop and bass roll off.

If anyone has questions, just ask.

 

[khbaur330162]

I just wanted to note the 400Hz dip myself and put it in my own words.

I agree with @Philimon that there is an issue in this region. I don't normally notice it so much with male vocals as much as I do certain instruments with lower midrange registers such as saxophones and stuff. With T50RP's these instruments can sound nice and meaty, dynamic, real girth to the notes. Even with damping to smooth FR in YH-100's, they never sound as gripping in this region. I just wrote it off as a deficiency of the driver, I was never able to match T50RP dynamics in this region even through EQ.

 

[Philimon]

I just wanted to note the 400Hz dip myself and put it in my own words.

I agree with @Philimon that there is an issue in this region. I don't normally notice it so much with male vocals as much as I do certain instruments with lower midrange registers such as saxophones and stuff. With T50RP's these instruments can sound nice and meaty, dynamic, real girth to the notes. Even with damping to smooth FR in YH-100's, they never sound as gripping in this region. I just wrote it off as a deficiency of the driver, I was never able to match T50RP dynamics in this region even through EQ.

I dont know. You could say 400Hz dip or 2kHz bump. Ive now decided to interpret as the latter since I found it easier in this case to eq to preference with subtraction than addition. Flattening the 2kHz area leaves behind a nice little bump in the low bass (just the way I like it).

The Yamahas (and T50RP to lesser degree) can have all the tone and texture of bass, but not the rumble or impact. Your mod does improve the latter aspect over stock but its still lagging. But its really dependent on the music too for it to be even noticeable to downright disappointing.

edit: Its been awhile since Ive heard a t50rp and Ive never heard any of the ones with aftermarket cups which I believe do a lot to help.

 

[Philimon]

I posted measurements of khbaur’s YH100 mod earlier but I only measured LEFT side. There turns out to be a slight imbalance. RIGHT side has more bass which is what I expected from the deeper pads compared to stock.

Edit: Im going to troubleshoot. The driver baffle has vents. khbaur sealed the vents but Im going to double check.

Edit2: I purchased a YHD-1 for the Yamaha compendium on that other friendly site.

 

[Philimon]

Graphs attached for part of my comparative impressions of YH100 vs YH1 vs YH100 khbaur.

The YH100 and YH1 were both modded with basic mods: foam + felt. Both require EQ for me to enjoy as seen in graphs (Loki+ 2k@9). I will be using them with EQ for comparisons because I like my ears not hurting. khbuar's modded headphone doesn't really need EQ if it were in good order in both channels, but the problem is that his LEFT channel has a bass roll off that requires EQ. Unknown if channel imbalance is due to the driver or whatever.

--------------------------------------------------

Basic mods. It is my opinion that in general the Yamaha series don't need much in terms of modifications. What they need is refurbishment back to stock levels of damping. All the stock Yamahas used a combination of felt+foam for driver acoustic impedance and cup reflection absorption. Foam does expire. Today when we hear a Yamaha it usually has stale or disintegrated foam with worn pads (bad seal etc) so it's not in peak (or atleast original) operating condition. Some people's "peak" operating conditions is sometimes what I'd consider under or over damped. In other words, preference plays a part in what's peak or "properly" damped.

Underdamped will sound less HIFI with slower transients and less delineation. However, the slower transients in the bass regions may actually be closer to neutral / natural imo. These small planars are not for bassheads, but they have quality bass that pees on your 6XX's bass. Where Yamaha pales most is soundstage and tone (tone can be corrected with eq). Timbre Ill say is a wash at best in comparison to 6XX. I think 6XX is probably the best I've heard in terms of mids (highs I still give nod to STAX with rose tinted glasses) but the bass just does not agree with me at all for general music.

Overdamped will sound super HIFI. Problem is that you'll have cut the balls off your bass. It's too tightly controlled, no impact, unnatural, meek, lower amplitudes. Benefit is you have zippy mids and highs with high delineation which sounds really cool but ultimately not worth the trade off imo.

Stock or something closer to "properly" damped is the nicer middle ground imo. Not saying stock can't be improved with a different damping scheme. Where stock is most compromised is in the enclosure and pads... this is where khbaur's YH100 comes in with a driver transplant.... However, I'm not saying a driver transplant will morph a YH100 driver into an Audeze driver. Unfortunately I don't have an @Audeze here for comparison.

to be continued

 

[Philimon]

edit: nevermind

 

[Philimon]

DIY hybrid pads (mod11) ; ring of thick felt underneath inner edge of pads.

Subjectively, idunno. I thought it sounded better but I didnt listen before measuring so biased. Specifically better in that I didnt feel a need to reduce 8kHz. I didnt do much testing. Was pleasantly surprised that it improved comfort. YH100’s extra weight makes it the least comfy between YH100/1/2.

Will try this with YH1 next.

edit: mod10 is the same minus the diy hybrid pad

 

[JadeEast]

2-3db down at 8K? I'll take that.

 

[Philimon]

2-3db down at 8K? I'll take that.

2kHz and 8kHz are my nemeses.
Interestingly and disappointingly is the next tier up Schiit equalizer (Lokius) changes the 8kHz knob for a 6kHz knob which is why I havent upgraded.

Also realized I need more more EQ reduction at 2kHz otherwise it sounds too brash (in your face) and bass will sound too dim (for me) in comparison. Loki 2kHz knob at 7o’clock (max deduction) is best.

khbaur’s YH100’s good channel (right) nails the tone well. Just wish both sides were even. Its making reviewing difficult (impossible?) since I cannot eq one channel at a time. Some tracks will sound great with bass and others will sound lacking. Ill still compare but will have to make some estimates on bass qualities. The next reviewer I believe uses PEQ so can edit individual channels.

 

[Philimon]

Ordered a replacement headband support from ebay for YH100. The original was cracked and dull.

Attached is a comparison pic of a sort of before / after with another YH100. And also attached is a pic of stock mounting tab (left) vs replacement.

The aftermarket replacement is spot on except the mounting tabs are a couple mm too wide and needed some trimming with scissors. Recommended!