[khbaur330162]

More thoughts on YH-100 production variations​

So far I've seen:

#	flux plate type	ground pin type
2	matte	Copper
1	matte	Silver
1	brushed steel	Silver
4	shiny	Silver

If anybody sees this who owns a YH-100 and is willing to open them up to verify production era and serial number for me I'd greatly appreciate it. Hopefully we can get some more tally marks and try to figure out the appearance rate for each type. Also, there may be more variations that I don't know about?

Again, for reference:

Matte + Copper

Matte + Silver

Brushed Steel + Silver

Shiny

 

[Philimon]

Interesting observations @khbaur330162 . Im wondering if the sound differences are due to variance or changes in production over time that effected magnet strength. Or sound differences could be something else? I see "matte + silver" the plates + magnets dont line up very well and perhaps that having a certain effect on sound.

 

[Philimon]

I hardly listened to my NAD RP18 modded by @takato14 because preferred Fostex T30... RP18 mod arrived to me with some L/R channel imbalance but assumed was due to the asymmetric shape of the worn aftermarket pads. [If interested Ive posted info on this mod before earlier in this thread or sbaf thread, am too lazy to search atm.]

They do sound good and would be interesting to contrast against HE500 so may do later. From memory, Id guess they are on similar level all in all with RP18 being slightly brighter (beyond preference). Both headphones have been modded, both have original drivers installed into HFM 4XX enclosure and headband.

Spoiler: mehsurements, EARS

Im going to padroll and see if I cant suss out channel imbalance (not shown here). Hopefully not a driver issue like Fostex T30.

 

[khbaur330162]

Im wondering if the sound differences are due to variance or changes in production over time that effected magnet strength.

Me too. Yamaha obviously was putting a lot of attention towards the flux plates for a while, trying different alloys and treatment processes it appears. All of this is to keep the magnetic flux compact and saturated over the diaphragms. Whether or not they changed the ceramic ferrite formulation at some point is not hugely important because we can already assume gauss measurements differ over the diaphragm depending on flux plate type. But it is interesting. What direct effects does magnet strength have over the sound?

Or sound differences could be something else?

Yes, I am wondering this too. I have re-cabled many KH-100's and most of them have had different cables from one another. How much of the technical differences I am hearing is strictly cable differences? It is hard to say. Also, I recently built a KH-100 using a Sony MDR-Z1000 housing. It is the same housing as all the others, basically, but instead of plastic some of the parts (driver housings, parts of the headband and yokes, etc.) are made out of Magnesium alloy. Does the metal have any sonic properties versus the plastic? Unknown at this point, but the KH-100'ed Z1k sounds really, really good to me.

I see "matte + silver" the plates + magnets dont line up very well and perhaps that having a certain effect on sound.

Perhaps. I doubt it, though. See here, I have been playing around:

If you zoom in you can see that this fuzzor is not perfectly aligned with the magnet perforations. It is not ideal, I probably tried to fix this after the photo was taken, but sonically? Very hard to tell anything is wrong, hardly alters the sound at all.

I hardly listened to my NAD RP18 modded by @takato14 because preferred Fostex T30... RP18 mod arrived to me with some L/R channel imbalance but assumed was due to the asymmetric shape of the worn aftermarket pads. [If interested Ive posted info on this mod before earlier in this thread or sbaf thread, am too lazy to search atm.]

They do sound good and would be interesting to contrast against HE500 so may do later. From memory, Id guess they are on similar level all in all with RP18 being slightly brighter (beyond preference). Both headphones have been modded, both have original drivers installed into HFM 4XX enclosure and headband.

Spoiler: mehsurements, EARS

Im going to padroll and see if I cant suss out channel imbalance (not shown here). Hopefully not a driver issue like Fostex T30.

Nice looking measurements.... Looking forward to impressions versus HE-500. Micro and macro? Imaging? He-6se v2 had very good imaging, but RP-18 is also no slouch here so versus HE-500? Bass slam?

 

[Philimon]

RP18 @takato14 mod, but with Harmonicdyne Athena pads instead of the velours that T. used.

Spoiler: mehsurements, EARS

^ L/R imbalance is improved but still apparent in measurements. Not sure its enough to be noticed subjectively... my short listens say not noticeable. Maybe not a driver issue, maybe mods or measurements. I will continue padrolling as I dont think the Athena pads are a good match, too non-breathable (no other front-side venting) and creating slight sense of trapped air pressure which ime can cause perception of smeared bass and cause ear fatigue. However, I do like the warmth added by Athena pads. [Please ignore L/R differences in highs shown in EARS rig. My EARS rig has not been calibrated in highs for L/R balance, I generally only use Left side for measurements with EARS as I've "refined" calibration file.]

Here are FPC L/R measurements with T.'s velours for comparison.:

Spoiler: mehsurements, FPC

^ Takato14's velours are more breathable and will effect sound beyond frequency response. T.'s mods were done with the velour pads in mind so not fair to judge his mod with alternate pads. [Differences in FPC L/R measurements could be related to positioning on mic coupler or headphone imbalance whether mods, pads, drivers, etc. Mic, coupler, and calibration are same for both channels.]

HE500 with Dekoni hybrid pad measures for comparison:

Spoiler: mehsurements, EARS

^ Could use improvement, padrolling is expensive... Plan to fuzzor mod later.

 

[khbaur330162]

You can try adding more cup filler to the right driver housing only (small amount), it should even out the bass between channels.

 

[Philimon]

You can try adding more cup filler to the right driver housing only (small amount), it should even out the bass between channels.

I could but I dont think the L/R imbalance is noticeable subjectively. I edited my post above to make that statement more clear.

Ive a few other pads I could try that are more breathable. Will update later with comparisons to HE500 after settled on new pads.

 

[Philimon]

I hardly listened to my NAD RP18 modded by @takato14 because preferred Fostex T30... RP18 mod arrived to me with some L/R channel imbalance but assumed was due to the asymmetric shape of the worn aftermarket pads. [If interested Ive posted info on this mod before earlier in this thread or sbaf thread, am too lazy to search atm.]

They do sound good and would be interesting to contrast against HE500 so may do later. From memory, Id guess they are on similar level all in all with RP18 being slightly brighter (beyond preference). Both headphones have been modded, both have original drivers installed into HFM 4XX enclosure and headband.

Spoiler: mehsurements, EARS

Im going to padroll and see if I cant suss out channel imbalance (not shown here). Hopefully not a driver issue like Fostex T30.

RP18 (takato14 mod) with Defean hybrid pads. fyi, these pads are seemingly commonplace on the internet but when I bought a set they were from vendor "Defean".:

Spoiler: mehsurements, EARS

for reference vs HD600 (2022):

Spoiler: mehsurements, EARS

for reference vs HE500 with Dekoni hybrid pads:

Spoiler: EARS, mehsurements

I've not compared them side-by-side yet but I'd still guess RP18 and HE500 are very similar overall. Im guessing its a case like HE6se (modded) vs HE500 where they were very similar overall, but HE500 wins for a few tiny differences that I value more over HE6se's tiny advantages. Unsure what all advantages RP18 might possess, bass seems to hit harder but that could just be differences in pads + tuning but I suspect not. Out of convenience I mostly listen to Grado (F-pads) from iPhone dongle these days so dont have a strong enough memory of HE500 to make any confident comparisons atm. ... And I just took the RP18 off because I want to get up and move to something else with Grado in attachment.

HD600 is definitely a tier below in terms of tonality (imo) and bass clarity, and approximately even otherwise.
*Equipment: ModiMB > Jot2 balanced output

 

[bananasplit 00]

Ive gotten a bunch of time to use both my HP-1s and my K245 with HP-50A drivers over the last few weeks.

Two takeaways are that even the suuuuuuper thick and soft pads on the HP-1s dont make them comfortable enough for several hours of listening(they pinch my glasses to my head and give me headaches ) and that the stereo experience is incredible with orthos compared to everything dynamic i have(Sennheiser HD558, Sony WH1000XM3, ATH-M50x, other lower teir stuff...).

It really is that 3D experience that i dont seem to get with anything else. Really thought there was a significant L/R imbalance with all my DIY amps or ortho headphones but i cant pick up any difference if im playing mono tracks or tones (or with an oscilloscope on amp output for that matter if you cant meassure it, it aint there!).

 

[khbaur330162]

Ive gotten a bunch of time to use both my HP-1s and my K245 with HP-50A drivers over the last few weeks.

Two takeaways are that even the suuuuuuper thick and soft pads on the HP-1s dont make them comfortable enough for several hours of listening(they pinch my glasses to my head and give me headaches ) and that the stereo experience is incredible with orthos compared to everything dynamic i have(Sennheiser HD558, Sony WH1000XM3, ATH-M50x, other lower teir stuff...).

It really is that 3D experience that i dont seem to get with anything else. Really thought there was a significant L/R imbalance with all my DIY amps or ortho headphones but i cant pick up any difference if im playing mono tracks or tones (or with an oscilloscope on amp output for that matter if you cant meassure it, it aint there!).

That M50x can house 46mm ortho's fairly easily.

 

[ludoo]

A bit off-topic, but I recently modded my Koss ESP/950 filling the cups with the Visaton speaker damping material I mentioned in an earlier post, which I found incredibly good with my small driver Yamahas and Audeze LCD-1.

I measured response before and after the mod using my DIY flat plate rig (which means ignore the FR as it's not representative), and while I am a measurement noob it looks like the damping is working to reduce reflections. The change is audible, as the graininess in the treble which bothered me has disappeared.

CSD plot before the mod

CSD plot after the mod

distortion before

and after

 

[Philimon]

DIY flat plate rig

Nice.

I think others who have tried distortion measurements can attest that getting consistent results can be difficult due to environment noise floor. I researched some and considered building an enclosure just for headphone measurements but lost interest.

ime CSD like frequency response measurements are not as susceptible to interference from environment noise floor. Still, I measure at 90dB+ to help over come noise floor.

Ive no good comments on measurement accuracy or correlations to subjectives. I think data from consistent and clear methodology is good but Im no scientist or that knowledgeable in general. I measure just for fun and to help with my mods. Thank you for sharing Ludoo as I like seeing other people’s experiences as well.

which means ignore the FR as it's not representative

Appreciate the heads up.

In my profile Ive this:
Mehsurements by EARS or FPC (retired)
Measurements just for relative comparison and lols, do not accept as accuracy or highly relative to your personal experience.

 

[Philimon]

In case anyone else is looking to get into measurements here are some tips.:

1. Measure at 90dB so as to exceed environment noise floor for more reliable measurements.
2. Take several measurements of a headphone while slightly altering positioning between each run, then average the responses. This will allow you to see if there were any outlier measurements for x reason, and will allow a more generalized measurement since in irl we dont consistently wear headphones perfectly down to the mm, and those changes in mm could have a big effect on how the highs are heard…

Optional:
3. For ease of use, try to maintain consistency in graph limits (x, y). This will build familiarity and over time allow quicker analysis.
4. I like using 100dB y-axis and 20-20kHz x-axis because that seems most common standard so makes triangulating against other rigs easier. And I like using 1/12dB smoothing. Yes, both options do make measurements look simpler and more appealing, but I find it helps with my neurosis of trying to get a “perfect” mod.

EARS is mostly plug and play so highly recommended for simple hobbyists. diy FPC has its own strengths and weaknesses. Both are limited and are definitely not the latest on accuracy…

REW of course is highly recommended. I think REW and EARS are now sympatico to where REW can spit out PEQ computations for target curve, but havent looked into so dont know for sure as I dont use PEQ.

 

[GREQ]

4. I like using 100dB y-axis and 20-20kHz x-axis because that seems most common standard so makes triangulating against other rigs easier.

My graphs always go down to 10hz.
There's a huge amount of information lost there in so many graphs that tells us a lot about the personality of a headphone and it's technical ability from just these 10hz.
Also, the "humans only hear from 20-20K" is a myth. My hearing goes from roughly 8hz up to 16KHz.
The problem is there are VERY few headphones that can actually produce discernable tones/frequencies down to 8hz, so many also assume those frequencies are inaudible.

So many times I see graphs that look relatively neutral until a steep drop off just before 20hz which doesn't get shown properly - but there are many headphones with superior sub-bass performance all the way down that have a different character.

In my experience, headphones that have better sub-bass performance tend to have better overall bass resolution and texture, and the added sub-bass can also add a bigger sense of scale to the sound.

All of Tyll's graphs on Innerfidelity also went down to 10hz

 

[ludoo]

I think others who have tried distortion measurements can attest that getting consistent results can be difficult due to environment noise floor. I researched some and considered building an enclosure just for headphone measurements but lost interest.

Yep. But my rig produces pretty repeatable results, and any data taken with a repeatable process and conditions which are as identical as possible (I never move my rig, and make sure background noises are absent) is better than no data.

TBH I don't look at distortion charts a lot, but case in point: distortion measurements for 4 different small Yamaha drivers (2 HP-3, 2 HP-50A) all damped differently and taken at different times, they show the same pattern.

bass-heavy HP-3 (probably my favourite phone ever)

bass-light HP-3 (great positioning, superb for acoustic jazz)

HP-50A #1

HP-50A #2