Yamaha HP-1A Analysis and Review

Background

I knew Yamaha’s vintage models were frequently mentioned and loved by vintage ortho fans, but when I could borrow an actual pair from @Philimon, my expectation was far from being high. How can I have a hope for the combination of small drivers (for ortho), supra-aural drivers, and small closed-back enclosure? The list of such keywords sounds like a huge acoustic disadvantage. Well, I wasn’t 100% wrong. What I didn’t expect, however, was I ended up getting my own pair. OMG.


Subjective Evaluation

Before jumping into my thoughts, let me explain a little bit about my on-ear headphones history. I don’t think I have much experience with this type of headphones. Many years ago, I happened to hear B&W P5 and Beats Solo2, and liked them both. Grado couldn’t impress me but cut through via F-cushion equipped Hemp. For a stable daily driver, however, the former group lacks technicality while the latter was painful in ergonomics. So, that’s where I started my time with Yamaha’s vintage on-ear headphones.

What did I find out? In short, they fit very well with my day to day life needs. Summary of specific thoughts below. All the evaluation was done via Soekris DAC 2541 and its builtin headphone out.

What I like

• They’re comfortable. At 275g in my scale, they were not particularly lightweight for on-ear headphones (orthos can’t beat dynamic headphones in weight for the same sonic performance). But, Yamaha put a lot of thought into designing straps, clamping elastics, and ear pads. All these components combined with the sub-300g weight simply nailed it in the ergonomics game. I could literally wear them for the entire 8 hours during a work day without being bothered. I was very surprised at this point as all the other vintage orthos I tried were (albeit with some impressive sonic merits) shitty in ergonomics and did not consider human comfort at all.
• HP-1A comes with non-aggressive tone balance. They can render vocal sound moderately meaty and wet with good presence/sharpness. While they’re a little mid-centric sounding, fatiguing points were very well controlled without disjoint or disconnection across the spectrum. My limited experience of vintage headphones was most of them hardly obtained acceptable tonality in stock. Honestly, HP-1A is too well-balanced for me to hastily desire additional mods.
• Another sonically surprising point was their ability to portray space. I don’t usually expect too much of this for small drivers, but when I threw in Abyss dummy-head test recordings, they could discern extremely well between 6ft-9ft distances in staging. Also excelled in imaging accuracy between 0-45-90 degrees. Maybe a little exaggerated than actual distance/angle, but note that such exaggeration is clearly associated with better spatial feeling in playing non-binaural tracks via headphones.

What I don’t like

• I have been consistently bothered by the annoying sound in two different sites. One place was diaphragm. It does sound like being crumpled or wrinkled whenever I push ear cups inward. Audeze LCDs with legacy air-tight ear pads had this character, but to less extent. Another annoyance comes from plastic disjoints that connect ear cups to headbands. Seems some plastic parts in the cup scratch each other and generate uncomfortable noise. This occurs when I reposition them on my head. Not a serious deal breaker, but something I want to fix asap.
• Bass extension is limited. For small drivers, it might be an acceptable shortcoming. But I found anything below 50hz was quite muted. I should only depend on the recorded harmonics when I hear low frequency instruments. Fortunately Yamaha didn’t take the upper-bass boosting approach, which makes HP-1 lows clean and not bleed into midrange.
• I have three vintage orthos in the house right now. HP-1 is the least technically capable among the three. Small drivers in small cups always have this disadvantage. Not surprising.

Comparisons and other thoughts

• My modded HD6XX was warmer and airier. Not to mention comes with better details and dynamics. But I prefer HP-1A’s cleaner, less-congested, and less-veiled presentation in most of my favorite tracks. HP-1A also portrays larger stages with more believable imaging placements by comparison.
• Interestingly even with closed-back housing, HP-1A was more open sounding than the modded RP18/T30. But except for a few sonic criteria, those larger cup orthos resolve detail and dynamics more effortlessly. Subtle vocal nuance and techniques were better heard with the latter group by comparison..
• If I recall correctly, HP-1A is technically far superior to B&W P5 and Beats Solo2 in any metrics. Also it must favorably rival the Hemp. I want to make it clear that all the advantages I described above were quite irreplaceable with any on-ear headphones I’ve ever heard.

 

Objective Measurements

It's always challenging to take measurements for on-ear headphones particularly with dummy ear couplers. Channel discrepancies shown below are largely asymmetric position and seal between the channels. Think them as a positioning variance.









More thoughts on the measurement to come later.

 

By the way, I'm calling HP-1 Anisotropic magnet version as HP-1A for the convenience. I think I've seen a post explaining Yamaha model variation (YH1/2/3, HP1, YH100, etc) somewhere in the sbaf, but could not locate at the moment. Probably buried in the vintage ortho thread.

 

If you look in the vintage ortho thread you’ll see that with mods its very easy to get bass down to 20Hz. You may not like the tradeoffs but its fun to try. More damping equals faster transients and increased microdynamics. At a certain point though you are overdamped, and lose macrodynamics and bass extension etc

 

Thank you for the analysis @Vtory . Would be interesting to compare against a @rhythmdevils modded HP-1a.

Would like to hear your thoughts on the HP-2* which is my preference due to no upper mids bump and more even highs. You lose in other areas (smaller driver) but worth the trade for me.

*Many alterations during production run, so not all sound the same, but in general a sweeter sound on the smaller HP|YH-2.

How do you know?
Im glad you bring up something I can disagree on. The vintage ortho with the best stock sound is the Fostex T10.

Lots of vintage headphones have poor ergonomics. The Yamahas are exceptions. The Fostex T30’s stock enclosure is “a torture device” (@wualta).

Not normal but not uncommon to find on these old headphones.
Caution from @dBel84 :

Spoiler: Do not try to fix crinkle.

Many of the center pinned orthos have this crinkle, I think it relates to the pressure placed on the membrane when you seal them to your ears.

Regarding the reseting and tightening. Only at very high risk. The pin is a rivet. There is no loosing and retightening only removing and replacing which I have never seen done without breaking the magnet.

People used to try twisting the magnets to tighten very loose membranes but it often tore the driver at the base of the rivet.

I would strongly recommend against allowing anyone to try any of these tricks. You have a rare gem, it would be sad to see it damaged.

 

Thanks for calling out my BS statement. I was tipsy when I was doing the writeup (not to mention hearing hp1a, too). I corrected it now. My prior OOP ortho stock experience was earlier revisions of T50rp and they were not good in stock at least to my ears. It seems I over-extrapolated. I heard Sony and Koss vintages (didn't like them much) but they were not ortho.

 

I always wanted to see measurements of more stock orthos. I always thought that damping a driver properly can decrease distortion and it can! My modded Yamahas don't have distortion like that, or anywhere close. Very cool.

 

Thoughts on Measurement Results

• In the FR plot, mild discrepancies of 1-2db observed between the channels, however as I wrote above, run to run variation for on-ear headphones measurement is very tricky. Subjectively I couldn't hear imbalance problem much.
• Bass rolls off quickly from 90hz in my measurement, but please DO NOT take this as is. It's mostly determined by how ear pads attach to silicon dummy ears. For example, if I push them hard inward via something like rope/string, bass extended to much lower frequency. I personally feel like HP-1A did bass a little deeper than the graph suggests atm. Also based on my listening session, I roughly speculate resonance frequency of HP1 is tad lower than HD6XX.
• THD plots show HP1 control non-linearity better than RP1 as well as T30 (the later to less extent) with louder signals. Impressive for small drivers. I recommend to anything shown below bass roll off points because it isn't very informative.
• Applying the same rule (ignore anything lower than 90hz), I'm also impressed by harmonics breakdown. D3 and D4 were all well below D2. D2 soars at 2.5khz and 5khz which I'm suspecting more of EARS artifacts or the compensating process. Hard to tell which is the right story without further investigation. Subjectively I didn't hear anything wrong in those range.
• CSD was also subjective to run to run variation. So it might be better to take an average of the two channel in your brain prior to giving any interpretational shots. Considering Yamaha did not put a lot of damping material in the housing (speculated from the fact most modders add internal damping), cup resonance is decently controlled for closed-back headphones to say the least.
• Resonances at 2.5khz and 5khz seem debatable in audibility. I'm personally less sensitive to the latter one. I experimented several EQ filters to weaken 3k hump a bit and CSD linearly responded to whatever gain I applied around 3khz. Good thing in my book.
• Except for those two resonances, initial decay to the -15db point is fast and clean, which is consistent with my subjective observation.

 

I had a set of YH-1 back in the day, which were stolen along with most of my stereo gear when we were out of town. Insurance replaced them with the then current model, the YHD-1. Not only did they not sound as good, they were like a medieval torture device! Still have them, but haven't used them in ages...

 

Very glad to update this thread. I’m revisiting HP-1A. Not the stock unit but a modded one this time around. A hard working staff, ortho guru, skilled modder, and -- maybe most importantly -- my friend, Whitney (RD) loaned me his modded pair to evaluate myself. I got HP-1 along with YH-3. More on yh-3 later in other posts.

As I posted earlier, I was already quite impressed with the stock unit. Technical capability seemed a little compromised to me though. And the mod surprised me in this very way.

My early thoughts below. But most might be a little too enthusiastic and possibly biased, too. Please de-bias them enough before taking anything seriously.

Spoiler: Over-enthusiasm Alert

BQ/Comfort

• Not to add much to the stock. I’d reiterate Yamaha did a fantastic job in the ergonomics.
• But the modded unit addressed two of my original issues
  • First, the mod improved plastic friction a bit (if not entirely gone). Once they sit on my head, I hardly hear friction noise even when I nod or shake my head.
  • Second, I don’t hear the diaphragm's wrinkling sound any longer. Probably due to the changed airflow paths.

Dial-in

• While the tonal balance of the modded unit was already decent albeit a bit revealing in highs (maybe slightly brightened over the stock), I wanted to dial in more with some additional corrections on my end.
• This was done very quickly and I can comfortably say Yamaha’s legendary ortho is very EQ-friendly. Along with the line of many other modern orthos.
• To be specific, I cut the mid treble broadly then boosted the lower treble a bit. Way simpler than any correction works I’ve been doing for other headphones.

Sound

• Without the digital correction, the modded unit reminded me of JAR 580. After applying EQ, the sonic balance sits between JAR580 and HD650. Maybe a tad darker? Please don’t get me wrong. It’s only about tonality. This modded unit can do far better beyond Senn cans when it comes to technical rubrics.
• There are too many things I want to praise about the modded hp1a, but most importantly I was enamored by the timbre. It’s very polished and brushed-up. Insanely dense without sacrificing meatiness. Let me put it this way. My modded hd650 feels like tasting raw meat. Real but not very engaging to my untrained tongue. This modded hp1a is more like dry-aged, salted, msg-ed, buttered, and properly seared meat.
• I’m also quite surprised that Yamaha headphones can resolve this much detail and nuance particularly in vocal tracks (the headphones are a little mid-centric by nature). I didn’t think the stock was suitable for uncompromised listening, but this modded unit is definitely able to serve for most serious purposes.
  • This detail retrieval creates good synergies with dense/flavorful timbre. Shortly speaking, too additive to stop listening. I’m not joking.
• Head-staging accuracy was where I liked the stock. RD’s mod remains more or less the same here in terms of accuracy and size. Nonetheless, the mod comes with much tighter images and mildly better openness/airiness (drilled holes seem to work!). Very pleasant improvement in my book.
  • Higher end Stax and HFM do this better with more holographic presentation and better layering. But HP1 seems to be handicapped by its cup size and supra-aural structure -- there’s not much complicated interaction between ears and airwaves which I believe essential for top level 3D.
• My one grief so far is this loaner was terminated with TRS and my amp sounds better when balanced. I’m betting there must be a healthy improvement if they’re driven off bal outs.

To summarize..

So.. that’s pretty much about it for now. I am planning to explore more with this loaner unit possibly with more tracks and more AB comparisons. Will measure them, too. Stay tuned!

 

As someone who wouldn't use DEQ but would consider purchasing a RD modded Yam, I'd like to read more impressions about the sound without any DSP. You mentioned tonally it was somewhat similar to a JAR580 without EQ, but you also said you EQ'd down the mid treble and EQ'd up the upper mids. Would you also have applied a similar EQ curve to JAR580 to achieve your preference target? That would be a lot of upper mids... If it sounded more like JAR650 (from a tonal standpoint only) after your EQ curve, that would have me thinking without EQ it probably had somewhat dark upper mids, but that contradicts your comparison to JAR580 from a tonal standpoint which certainly doesn't have mellow upper mids.

I've enjoyed your comments regarding the other technical aspects of the headphone's performance and I'm looking forward to hearing it someday, but as a prospective buyer I find it very hard to gauge the tonality of this headphone from your impressions! I would want to hear RD's unadulterated vision and the use of EQ in the context of a review of his work feels mildly irreverent and has me scratching my head about his approach to voicing. In some respects, mods themselves are passive acoustic EQ already. There's nothing wrong with using DEQ to taste, but I find it a confounding variable in parsing out your impressions (not that they're not worth reading... I am intrigued already - I just want to read more outside of that context/use-case).

 

Good point.

Let me correct my wording a bit first. Looking at my filter values again, it would be more accurate to describe "lower treble" instead of "upper midrange". I corrected this in the post, too.

And just for clarification, I am using simple logarithmic scales in categorizing bass, midrange, and treble: 20-200, 200-2k, and 2k+ hz.

I don't have jar 580 closely now, and at the time I reviewed it, I was sorta scared to use eq, which was largely different from I am now. And I'm sorry if my description confused you. When I use specific product name in describing tonality, my intention is to compare rougher and broader level balances such as bass vs mid or mid vs high.

That said, to me, j580 was largely neutral but mildly treble > mid (I should check with my notes.. but that's what I generally recall). HP1 mod resembles it to some extent. I don't think energy distribution within treble would be necessarily similar between the two tho. If you want some numbers, I'd rather say the hp1 (modded) seems to have a little more energy between 4 and 8 khz than below or above. In the j580 case, I felt more energy around lower highs.

Finally, as you might already catch from my recent posts, I am less concerned with product tonality per se these days as they're kinda fixable on users' end. There are some additional variables for sure (i.e., not every headphone responds in the same way; some tonal issues are hard or almost impossible to work with eq; etc), but now I am in the camp focusing more on workability and correctability. I'm also more interested with what eq can't fix. So, this must be something to keep in mind in reading my posts.

Hope this can clarify a bit.

 

Thanks for the impressions so far!

@E_Schaaf can I send them to you when @Vtory is done? No rush at all Simon, there's few people on the loaner tour, so you can spend as long as you like with them

 

Sure!

 

I have a set of YH-3s and Elektronika TDS-5 (Soviet copy of HP-1 headphones). I put a wool felt - paper - wool felt sandwich in each which really improved them - got rid of the wooly sound. @rhythmdevils, I notice a bunch of holes drilled in the cups of the headphones in one of the photographs posted in this thread. What change do you get with those holes? Just more open? Apologize if that is a silly question.........

 

No questions are silly questions when it comes to modding orthos!

The holes open up the soundstage and add air, they remove resonance, which allows me to use less dense damping materials which I would otherwise have to use to absorb resonance, which helps open up the sound more and maintain bass presence. And the holes add bass presence which helps me damp the driver harder to get more treble out of them so they are balanced.

It's pretty cumbersome to drill the holes in an even way, but definitely worth it. If you decide to try this, it's not totally necessary that they are exactly even on both sides (but the more even the better), but it is very important that you drill the same number of holes on each side or you will get a channel imbalance.

 

Thanks! Appreciate the explanation.

 

Re: EQ

A little more on this part.
This can be a little pseudo-scientific talk about WHY I do this way.. so if you're not interested in such BS, feel free to jump to the actual EQ profiles for HP-1A!

Spoiler: EQ general discussion

I warned you haha.

Recently at some point of my journey I felt tired of including perfect tonal balance in my equation. I've been thinking about the issue for a long time.. and was emotionally motivated to give up.

My rationales

• We seem generally ok how we mess with FR in acoustic ways on users' end (positioning, leak, etc.).
• Things not shown in FR charts seem hardly affected by eq.
• And I also think perceived tonality is heavily impacted by tracks we hear. But that's something very difficult to control person to person variation by nature.

There were some psychological barriers I had. But..

• I've long been believing DSP makes sound worse to me.. but that's shockingly rejected by my own blind testing. Once in controlled testing, all the digital hassles I think I hear were mostly gone tbh.
• Measurements reveal that EQ don't affect harmonic distortion profiles as much as I believed (more on this in a separate post later).
• Most DEQ is minimum phase probably because of latency concerns.. but post ringing was ignorable to me -- this was also shown in the personal abx blinds.

So, there were not enough reasons for me not to use DEQ proactively. My perception now is it's somewhat equivalent to dial-in step in loudspeakers (optimize speakers placement, treat room with diffraction or absorption, and/or apply some room corrections.)

How to DEQ can be multiple ways. FWIW different people came to somewhat different conclusions. Let me over-summarize how they might differ..

• Approach A: Oratory/Reddit seem to adhere to the Harman target curve (at least 1/3 oct or even more intensively smoothed). He seems to build filters automatically. Computationally speaking, this is more or less the same as how REW optimizes filter gains, Qs, and frequencies. (Let me make it clear that this isn't weird way at all. With some assumptions, mathematically sound way)
• Approach B: Andrew/Headphones.com uses "Harmanized" Sundara response as the target. He believes there should be some ranges where response should be deviated from the harman target curve. Optimization process doesn't always seem to depend on software solutions. He seems to take care of filter frequencies a little more than Oratory. And in-ear measurements were rarely used as secondary data points (not necessarily all the headphones he eqes).
• Approach C: Mine mostly differ them in that (1) I don't rely on measurements and target curves. Measurements are usually done post corrections; (2) I mostly use (recording-wise) BAD tracks and tune my filters to bear such tracks; (3) I have certain rules/policies myself regarding DO/DON'T. Avoid large Q, Minimize filters on highs, Not to boost below resonant frequency especially for electrodynamic models. Etc Etc. Some not sufficiently scientific.. but all of them are what I learned from previous failures.

I indeed followed the proposed profiles based on A or B myself before.. but didn't find them effective for my needs. Not that useful as references to work from, compared to building everything from scratch on my end. A and B may be useful for some people, but I found C worked best for myself.

As I said in the quote above, at this point, I don't bother what stock or not-digitally-corrected FR would look like as much as I did before. As long as tonal issues are fixable, I'm very fine with dealing them on my end. However, there can be some people who want to know what unadulterated response would look like. "Linear distortion doesn't matter to me" can't be generalizable to others because of different beliefs, different use cases, different things to look for, and so forth.

Thus, for that purpose, I feel like it's better to disclose my filters. To be specific, how each filter is parametrized or what overall gain curves look like. The inverted gain curve must be closely related to my perception of spectral balance of the headphones. Some caveats below.

• Please note that my "flat" or subjectively perfect neutral spectral balance does NOT coincide with SBAF target curve in the EARS measurements. There exist some obvious discrepancies as long as I verified with my own measurements.
• My EQ is more product-specific. Due to the nature of how I eq, the resulting response is what I think the best for that specific product rather than invariant targets. For example, Oratory eq's resulting response is harman for any product. Andrew's is largely the reference product he had in his mind. Mine can VARY across products I work on.
• I've verified EQed responses for three products (HD8XX, L700, Arya SE) with EARS.. but they're meaningfully (up to 5-6 db) different from each other.

Spoiler: EQ for HP-1A RD

And.. below is what I applied for RD's HP-1A.



Short descriptions

• Filter 1: Some naively recorded female EDM vocals sounded a little sibilant to me. This helped a lot.
• Filter 2: After applying the above filter, I found guitars presence and snap were somewhat lacking. This filter countered it a bit.

The measurements will come at some point in coming days.. I am just too lazy to pull out EARS these days. Sorry for my procrastination.

 

Yamaha HP-1 (Anisotropic ver; Modded by RD) vs ETA Mini



Opening / Disclaimers

• While I am curiously looking at all the products RD or ETA come up with, I have financial conflicts with neither. Two headphones this post talks about are all sent to me without any specific instructions or rewards. I’m doing this just for personal curiosity.
• The HP-1 I’m evaluating now is almost a one-off product. I have no idea if RD is willing to make any more pairs. There aren’t many mint HP-1 pairs in the wild, either.
• The ETA Mini in this post is a demo pair and it may not have the production quality channel matching as per Ev
• All the evaluation is done with 2541 DAC and Zen Sig amp (see my sig for details). Since my amp sounds a little different between balanced and unbalanced outs, it’s possible amplification might be a confounder to some extent. I also tested with 2541 hp out but I doubt if any of my assertions would flip.
• I will honestly describe which one I prefer in each category.. Almost every evaluation criterion is NEVER free from individual mileage. Take nothing too seriously beyond fun.
• Since the main purpose of this analysis is to give both products comparative evaluation,I may skip most redundant general descriptions that I already made in other posts. So, feel free to refer to my prior posts to see my general evaluation for each. I’ll put links below.

Prior Impression Posts (EQ description included)

• HP-1 RD Mod
  • Impression: https://www.superbestaudiofriends.o...-hp-1a-analysis-and-review.11666/#post-374505
  • EQ: https://www.superbestaudiofriends.o...-hp-1a-analysis-and-review.11666/#post-374573
• Mini (Impression and EQ): https://www.superbestaudiofriends.o...essions-and-reviews-thread.11855/#post-374909

Comfort / BQ / Aesthetics

• HP-1 >>>>> Mini
• BQ or aesthetics isn’t too different. But I’d like to mention that stock HP-1 does suffer from plastic noises and diaphragm wrinkles due to mechanical flaws. RD addressed them in the mod. Mini is free from such issues.
• Wearing comfort is a huge, huge victory on HP-1. Yamaha did a fantastic job in putting one of the best suspension headbands on the planet imho. Soft cloth strap is very flexible on the head and can work for almost any weird head shape. On the contrary, Mini is only marginally better than Grado (which I don’t see high in the comfort game at all).
• HP-1’s vinyl pads don’t look or feel better than plether/leather/polyester (these are just my preferred ones btw). But they did their job better than Mini. On-ear headphones can be more fatiguing and stressing because ears directly contact surface materials. Trust me, many people including myself previously GAVE UP on-ears solely for this reason.
• OTOH, Mini has a better extension adjustment showing visible gauges which help to keep peace of mind if you’re obsessive to maintain symmetry between left and right extensions. Of course I like it.. But HP-1’s better comfort is too huge to offset with this small merit.

Sound wo Digital Corrections

• Mini >= HP-1
• Let me break down how I evaluate tonalities of both products in each frequency region.
• Bass (HP-1 wins): Mini extends better. I’d say I can clearly hear down to 35hz without noticeable attenuation while 40hz sound fairly muted with HP-1. However, HP-1 exhibits better quality bass in articulation and lack of ambiguity. HP-1 is particularly strong in presenting anything around 80-120hz which I believe is associated with many critical renditions (e.g., piano bloom, low voice fundamental, bass guitar weight, etc.). Hp-1 remains very clean almost at the level of over-ear orthos. Mini, OTOH, is humpier around 70-80hz to my ears which feels more engaging and easy fun in most of modern tracks. If you like 650 bass, then you may like Mini as well (I do think Mini is a lot better than 6x0 in bass tho).
• Midrange (Hp-1 wins): Mini’s V-tonality sacrifices this region somehow. That per se isn't a critical drawback if I solely enjoy Mini.. but unfortunately, it’s more obvious to my ears that Mini could not catch up with HP-1’s full-bodiness in many instruments (acoustic guitars and lower bodies of hi-hats in particular). Female vocal tracks also seem to favor HP-1’s stronger midrange: Male ones to a lesser extent. I’d also make clear that among six different combinations (3 pads * 2 orientations), Mini sounded the least recessed in mids with the very combination I used in this review (backward Geekria-L).
• Treble (Mini wins): To me ears, HP-1 mod is a few decibels recessed in presence regions up to 4khz and a little more nuanced around 5-7khz. In either way, HP-1 is indeed fairly neutral to me in highs, which is very surprising for RD’s sonic tastes (partly because he listens to better recorded tracks in general which may give more headroom to him to tune aggressively). Mini definitely has more energy in the lower presence region and develops a gradual peak around 5khz. This makes Mini “V-sounding” -- I’d emphasize all these are very tastefully tuned.. So please don’t get me wrong. Objectively I don’t think there is a supreme winner in this category. Everything comes down to which track you will hear. So… Mini won. I listen to a bunch of tracks involving Asian female’s sibilants (i.e., /s/, /th/, etc.) with rather poor mixing/mastering quality not to cut them properly. Mini seems to have a healthy scoop between 8-10khz which works my music collection more robustly.
  • Aside: Overall I found Mini has a lot more energy in highs than HP-1.. Knowing RD and Ev’s tastes somehow from their prior works, that’s a real surprise to me.
• Top end (Mini wins): Both headphones extend very well beyond 10khz. HP-1 had a little more airiness and Mini can render piano overtones a tad louder. Top end quality isn’t too different between the two.. But I found Mini has more cohesive connection between upper treble and top end regions, which results in a bit more solid experience with Mini.

Sound w Digital Corrections

• HP-1 >= Mini
• Details of digital correction I used in this comparison are described in prior posts (see the links above).
• Not surprisingly, EQ makes them closer. But I do think HP-1 can scale better by comparison with the filters I came up with. My general tonal preference is EQed HP-1 >= EQed Mini > Mini >= HP-1. This is largely because gently cutting HP-1’s highs enables one to enjoy fairly smooth treble (even smoother than Mini tbh) WITHOUT much fatigue in any tracks. Bass and midrange strengths remained the same -- indeed more cohesively connected to highs.
• From technical perspectives, it’s really Ortho vs. Electrodynamics. I don’t want to re-iterate a never-ending parallel discussion.. But at least I do think they resolve more or less the same amount of information but present differently.
• HP-1 comes with more punches, more liquid sounding, denser timbre, and stronger center images. Mini delivers more holographic rendition, imaging accuracy, and better transients. Pick your poison.
• Lastly but not leastly, I’m very enamored by HP-1’s vocal presentation. All the benefits I described above (both tonal and technical elements) play a perfect harmony in rendering any kind of vocal tracks. If I should pick only one for a SPECIALIST, it will be more likely HP-1.

Closing

• The shootout was way more fun than I initially expected. I was honestly concerned with the possibility they might differ too much to compare (not horizontally but vertically). That’s not 100% wrong.. But both could illustrate what might be two successful local optima (if not global extremum) satisfying the same guy.
• All things considered, I think the Mini is more suitable for a generalist while the HP-1 mod holds its value against anything as a vocal specialist.
• HP-1’s low spl sensitivity and its scalability/workability with digital eq seem to give it an edge to computer audiophiles. Mini can serve for more diverse and versatile needs (DAP, non PC-Fi, etc).
• Interestingly this HP-1 pair will visit Ev’s place once I’m fully done with its evaluation. Hope Ev can steal and transplant some of Yamaha/RD magics to his future products.. Ergonomics please!
• Will follow up with measurements once taken.

 

Thanks for the impressions!

One thing I'd like to clarify though. You've mentioned in my modded LCD-R thread and now here about my modded HP1a that they stray from my sonic target. I'm guessing you think the first orthos I sent you are representative of my sonic target, but its' the opposite. I had to stop listening to music for 7 years and could only listen to iems at first. It took me a while to recalibrate to my sonic target and sense of neutrality. The orthos I sent you before were a stepping stone along that path. I recalled them because I realized they were not representative of my sonic target. I've now recalibrated, and it's actually the modded LCD-R and these modded HP1a's that are most representative of my sonic target than anything else anyone has heard.

But tuning orthos and making headphones is more art than science. Everyone serious about making headphones, like every artist, has a vision in mind and every creation is an attempt at recreating that vision is physical form. You are never able to actually achieve your exact vision, you can only create things that get close, hopefully closer and closer. The thing that keeps artists going is the desire to create something that fully achieves that vision, which probably no artist ever actually accomplishes. Nothing I've ever made so far is an exact expression of my sonic vision, but my modded LCD-R is the closest of what has been heard, followed by my modded LCD-X and then this modded HP1a. Other headphones I have modded are closer than the latter two, like my modded LCD-4 and LCD-4z. But those will have to be shared later.

So these HP1a's' are an attempt to mod a headphone to get as close as possible to my sonic target. There are sacrifices that have to be made as the drivers/enclosure are incapable of fully achieving that target, so I prioritize what is most important to me and try to find a balance.

Also, my modded HP1a is not unobtanium, I have a way of finding HP1 Anistropic's that is very reliable. They cost between $250-$300 and my mod costs $350.

I'd love to hear your thoughts on the difference between stock and modded HP1a if you have the time

Thanks again for your thoughts @Vtory !