Review: Technics RP-HV100 – Golden Era.

Despite their pioneering role in portable audio, earbuds have progressively fallen out of favor with the advent of in-ear monitors. Firing from the concha, they forego the benefits of ear canal insertion, namely the secure fit and superior isolation favorable to on-the-go usage.

In fact, it’s not only the mainstream crowd that has abandoned earbuds, but also audiophiles. IEMs afford more tuning liberties due to a sealed front volume (the space between the transducer and tympanic membrane) leading to improved bass extension. The secure fit also enables the use of larger, heavier shells, allowing manufacturers to precisely tweak sound through complex damping schemes and multi-driver designs.

Sony IER-Z1R’s hybrid coaxial layout.

I’ve personally gathered a lot more experience with IEMs than earbuds, as I’ve always considered the latters’ performance ceiling to be lower. That’s why I’ve typically stuck to value-oriented models, including the $5 VE Monk and $12 Yincrow X6. Despite the top end models typically only retailing at a few hundred Dollars (vs. a few thousand for IEMs), I’ve developed strong reservations against making the jump. Hearing the $559 ATH-CM2000Ti and $299 Fiio EM5, I disappointingly felt that they failed to meaningfully work around the constraints of their form factor, clearly putting into question their raison-d’être.

Per contra, this shouldn’t imply support for their extinction. The absence of seal imparts a degree of openness, and the increased distance to the ear canal provides more “out-of-head” stereo imaging characteristics. In fact, those qualities have gathered small, but loyal communities of earbud fanatics, mainly in Southeast Asia. While this has driven a “Renaissance” of smaller Chinese manufacturers releasing countless models to satisfy enthusiast demand, the same cannot be said with larger brands, which have long deserted this market in pursuit of the less compromised IEMs.

The impressive earbud collection of Head-Fi user “ClieOS”

History & Engineering

Indeed, the landscape in the 80s was much different. The advent of the Walkman in 1979 disseminated portable audio. Earbuds were soon popularized by the Sony MDR-E252 in 1982, starting a trend that saw large Japanese firms focusing R&D efforts both at the entry and upper levels. This heyday of the premium earbud generated models that have become very valuable, thanks to their rarity and the deep pockets of nostalgic collectors. These notably include Sony’s sapphire diaphragm MDR-E282 and Aiwa’s amorphous diamond-coated HP-V99.

Sony MDR-E282 (top) and Aiwa HP-V99 (bottom).

Technics was also a major protagonist with the RP-HV100. Released in 1987 for 10000 JPY (~11800 adjusted for inflation, or ~100 USD), it was the top-of-the-line offering in a series of pioneering dual driver earbuds. The design rationale aimed at improving bass extension by using intricate venting to integrate a large 19mm woofer with a smaller 11mm tweeter that could fit the concha.

Technics RP-HV100 engineering diagram, highlighting various vents.

With vast resources, Technics built their crown jewel with exotic materials and complex manufacturing, namely depositing gold on the tweeter’s diaphragm.

Technics RP-HV100’s 19mm woofer (left) and 11mm gold-coated tweeter (right).

Discontinued in 1992, the HV100 has since become exceedingly scarce and expensive. In fact, in February 2018, a sealed pair was successfully auctioned off for 1 million JPY – over 9000 USD after conversion. Although this is an extreme case, nice examples typically sell for an astounding 2000-3000 USD, appealing to a very particular niche of collectors.

Madness.

Having recently found more interest in earbuds, I was fortunate enough to stumble upon an affordably priced pair listed by a Swiss pawn shop. A month passed by before their arrival in Canada, to my great joy.

Ergonomics & Efficiency

Despite the fancy presentation box, this earbud is packaged in an unassuming plastic case, which similarly to other earbuds at the time, can wind the supple linear crystal OFC cable conveniently. Do note, however, that it will not fit in the case with foams on. Earpieces are also made of plastic, with a metal Technics badge housing the woofer’s rear vent – nothing extravagant.

Good fit is absolutely crucial as it dictates the front volume’s size and seal, both of which drastically influence sound. Although deeper insertion and tighter seal provide superior bass extension and a warmer sound, this is challenging given the HV100’s small tweeter size and heavy woofer, which drags the nozzle up and away from the ear canal. I personally noted an improved fit with the Fiio EM5 “bass” foams, which gripped the outer ear better and reduced higher frequencies through acoustic impedance. Given my anatomy, I have achieved best results by abutting the larger “woofer” part on the inner antihelix, which provided ideal depth and angle of insertion. Nevertheless, this comfortable wear is still far less secure than typical IEMs, and more finicky than usual “EMX500” style earbuds.

I sincerely question the accuracy of its 28 ohm impedance and 106 dB/mW sensitivity spec, as the HV100 is decently power hungry for a small earbud. Although most portable sources will still drive it, I have relied on desktop amplifiers for optimal results. However, it is important to exercise care with volume control, as this earbud is known for tweeter failures with high power input.

Sound

Purchasing this “unicorn”, I understood that its mystique could simply be driven by collectors’ nostalgia. After all, how competent can some earbud from the 80s be?

Well, I was pleasantly surprised. Tonality displays rolled off sub-bass with a minor mid-bass to lower midrange bump, followed by an upper midrange to lower treble focus, all joined by intriguing textural quirks.

Bass

Despite extending better than most earbuds with its 19mm woofer, the HV100 remains unable to generate the sense of deep rumble conveyed by most IEMs. Thankfully, a conservative mid-bass hump adds heft to the low end, preventing it from sounding too anemic without intruding significantly into the lower midrange. This FR trait is supplemented by bass impact and dynamic contrast that is superior to most of its analogs, barring the punchier, albeit woolier and stuffier Yincrow X6. The HV100 also remains uncommonly articulate despite its characteristically liquid low end texture.

Do keep in mind that fit and foams play an important role here. Foamless, the HV100’s bass is tighter, but also thinner. A deeper insertion and thicker foam will improve extension and impact, but also strengthen the mid-bass hump significantly. Overall, although it won’t enthrall bassheads, I thought it did a fine job given the fundamental limitations of its design.

Midrange

This is certainly the highlight for me. Most earbuds I’ve heard were colored by strong middle midrange emphasis, coloring vocals and instruments with a characteristic “honk”. As such, the HV100 distinguishes itself through its perceived FR: there is a slight residual lower midrange bump, followed by a linear middle midrange and late (2-3 kHz) upper midrange emphasis. Although this sweet tonal coloration is surprisingly coherent for an earbud, what I found particularly entertaining was the timbral incoherence between both drivers.

The lower midrange packs a characteristically rich texture, with a somewhat rounded leading edge. Lingering decay adds weight to the fundamentals of piano, bestowing warmth and body to notes. This is likely due to the woofer’s contribution, which contrasts starkly with the tweeter. Progressing to higher frequencies, the gold-coated driver is coarser and grittier, adding crispness to brass overtones and breathiness to female vocals. It is noticeably lighter on its feet than the woofer, with sharpened attack and truncated reverb. However, what particularly impressed me was its exceptional dynamic contrast, trumping everything else I’ve heard in the form factor. Crescendos are strong, snare drums strike vividly, and energetic string passages carry tension that calls for the listener’s undivided attention. Although the peculiar incoherence in intangibles will turn away some listeners, I was personally captivated by the raw contrast this quirk injected into musical conveyance.

Similarly to bass, listeners can tweak the midrange to their liking. Going foamless enables the fullest expression of the tweeter, making the HV100 evidently shouty, but also sharper and more dynamic. Although thicker foams will warm and soften the sound, the tweeter’s bite and upper midrange emphasis never fully disappear, maintaining most of excitement with a more agreeable tone.

Treble

The tweeter’s upper midrange emphasis further continues into the lower treble, with a “fresh” sounding boost around 4-5k. Leading edge has crunch, and although texture is slightly metallic, this earphone appears devoid of significant peaks (albeit I have done most of my listening with foams). Also, while its treble extension won’t hold a candle to modern day BA/EST super tweeter IEMs, it still managed to convey a respectable impression of air and sparkle given a decent mid-treble presence prior to upper octave roll off.

Intangibles

The HV100 not only sets itself apart through unique tonality and texturing with capable dynamics, but it also pulls low level cues and recording artifacts with impressive ease. Nevertheless, despite the remarkable depth of fine detail retrieval, a sense of haze can be perceived, making resolution middling. Staging is another interesting quirk. I am uncertain of the woofer’s greater firing distance role in this, but the HV100 sounds atypically wide and tall for its form factor, displaying an uncannily headphone-like image.

Source pairings

I’ve used the HV100 on my main desk stacks: a Dangerous Music Convert 2 DAC into a Bryston BHA-1 solid state amplifier (sharp, dry and dynamic) and a Bryston BDA-1 DAC into an Apex Sangaku nu-tube hybrid unit (warmer, bloomier). Although the latter helped tame some of its aggression, I found myself reaching for the DC2/BHA stack more often, as it allowed for greater expression of this earphone’s liveliness and attack.

Verdict

Although I feel fortunate to have experienced the Technics RP-HV100, I came into this ownership with reserved expectations. After all, I had become familiar with the limitations of concha-firing designs and grown cautious of the hype that antiquated rarities are often unjustly subjected to.

Despite its sound quality failing to justify its multi-kilobuck trading price, I was absolutely delighted to savor a wide variety of albums with the HV100. Unpacking the lively coloration, unusual texturing, potent dynamism, and expansive imaging has charted further depths to my enjoyment of music through earbuds. With newfound appreciation, I now look forward to exploring other crafts ramified by the old-fashioned form factor. Although we will likely never witness a similar frenzy of esoteric earbud designs from audio titans, let us cherish those relics of the past…

… and celebrate a golden era of intrepid engineering.

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