First off, I'm relatively new to the world of high fidelity sound, having only begun reading Head-Fi threads a year ago, but since that time I've rapidly accelerated my understanding of audio and although I haven’t had a lot of time, I nevertheless have had the opportunity to test out a myriad of products, ranging from the cheap to the high-end. With each earphone that I’ve listened to, I’ve incrementally improved my understanding of what good sound is. To celebrate my first year of audiophilia, I've decided to publish my first review. Hopefully it is laid out in a way that is coherent and thought-provoking for fellow HeadFi-ers. I don't presume to be an audio guru like so many others on this forum, but I consider myself a person who is analytical (in logic, not necessarily sound preference) about my approach to assessing sound.
I chose the Superlux HD381F to review mainly because it stands out so well for its price point and its sonic presentation. It's also a relatively obscure IEM for HeadFi-ers. It has been reviewed before, but the reviewer compared it favorably to the “pantheon of greats” (Shure SE530, Westone UM3x, UE Triple.fi 10), and thus may not have been taken seriously. I’m going to try to take a slightly more grounded approach, although the review is still going to be largely positive.
Also, I apologize in advance for my wordy prose (this review pushes 5000 words), but hopefully the review is laid out in a manner that is clear and organized for readers.
I cannot tell you how many times, while listening to music with these IEMs, I've dropped my jaw and said out loud, "I can't believe I got these for less than $20." This statement should be the central tenet to take away from this review, and a great starting point from which I shall begin.
Good products are hard to find these days. Market saturation and uniform production from manufacturers have made differentiation of non-high tech products extremely difficult. Unless your product has more than two million transistors inside, everything is a crap shoot. Such is the case with the world of portable audio. In the iPod age, any Joe Schmoe looking to replace his white Apple earbuds can walk into a store and pick up a pair of earphones for $15, or even $1. If he's keen on hearing better quality from his iPod, he can even move upward to cloned selections of $50, $100, and more. Gone are the days where only a few specialized manufacturers make $400 earphones, while the rest languish in the cheapo range. There are now so many good products, and it's difficult to distinguish the great from the good, especially on the lower end. In hindsight, I too fell victim to the mass consumers' irrational exuberance when I bought the Klipsch Image S4 canalphones last February. Don't get me wrong, I loved the fit and style of the S4s, and they did deliver the rich low end and fun factor I expected out of the Klipsch sound signature, but they still tended toward the consumer style sound --- slightly recessed midrange, colored treble, and overly emphasized bass. I had resigned myself to the belief that if I were to hear a more neutral sound presentation from my headphones, I'd have to invest a lot more money. Thus, I happily used my S4s until sadly and inexplicably, the left side died on me and I was left with nothing to listen to. No longer able to tolerate the sound of stock earphones, I fretted about the prospect of having to buy poorer quality earphones. With my financial situation as a simple student, I couldn't afford to drop $350 on a Westone UM3x. I had to look elsewhere.
Superlux is a Taiwanese audio company that is known for their microphones. For a couple of decades, they carved out a nice little niche market of budget PA systems and KTV microphones, as well as OEM/ODMing for the likes of AKG, Audio-Technica, and Sony. These past few years, they’d also begun to make personal audio products. Despite their own products’ appearances as low-rent versions of more well-known products, Superlux managed to garner a small cult following of audio enthusiasts that found their products to be great audio reproducers while at the same time being light on the wallet. One prime example of Superlux's bang-for-buck appeal is the full-sized HD668B, which were critically acclaimed as $30 (initial asking price) technical monsters that were on par with or bested other ~$100, highly-respected headphones (e.g. AKG K240 series, Alessandro MS1, Audio-Technica ATH-AD700). Its little brother, the HD681 was likewise a popular product amongst enthusiasts looking for a cheap, modification-friendly headphone that sounded great.
Lost in the middle of these large cans were the small, semi-open HD381 canalphones. At an MSRP of 690 NT (<$25 USD) and a street price of <600 NT (<$20 USD), these IEMs were often packaged as gifts accompanying Superlux's full-sized headphones or sold in a bulk variety pack of three, with each HD381 type offering a different sound signature. The 'F' model is the 'flat' variant, offering a more neutral response curve, while the 'B' model is 'balanced', and the unmarked one the typical consumer-oriented, bassy model.
In my panicked state of not having headphones to listen to and with little money in the bank, I bought the HD381F as a leap of faith. I'm happy to declare that I not only landed on both feet (or both ears, if you will) but am now recommending others to take that same leap. Mind you, these impressions are only for the 'F' model of the 381 series, and not any of the others. I cannot vouch for the sonic integrity of the other models in the series.
DESIGN, BUILD QUALITY & ERGONOMICS
Design & Ergonomics
The HD381 line is a 'clone' of the Sony MDR-EX90LP. In all likelihood, Superlux once were the ODM/OEM for Sony’s now aging IEM, and thus used the same outward appearance, exchanging the metal body for cheap plastic. Both also use the same sized 13.5mm drivers. The idea of mounting an earbud-sized driver oblique to the ear canal is not a new concept, and Superlux likely followed this model to create an IEM that sounded great at a low cost.
The package includes a shirt clip and a cord winder, as well as a selection of small, medium, and large silicone ear tips. The different sizes are color coded (small is clear, medium is grey, and large is black), and offer a comfort level commensurate with most other silicone tips out on the market. In particular, I find the smallest ones to be most comfortable, but I normally opt to use Comply T-400 tips instead (to tame the treble, more on that later).
In general, comfort is an issue at the onset of putting the HD381F in the ears. Most large driver IEMs and earbuds are awkward to wear at the beginning, but once a wearer is used to the earbud-style fitment, the comfort is not all that bad.
Let me get this out of the way. The build quality is BAD. The entire enclosure is made of cheap plastic, and the strain reliefs simply don’t earn their lunch money as such. It’s easy to see why the HD381 series hasn’t sold well; its build quality would be questionable even for the average consumer coming up from the iBuds. When putting them on, there is significant driver flex especially with pressure-sealing triple-flange eartips. This type of shoddy build is poor even for Superlux’s standards, whose products are normally well put together despite their use of predominantly cheap plastics. It is this very build quality that will be the major deterrent for anyone considering buying them.
Foreword about sound assessment --- I don’t have much high end equipment (yet), and thus all comparisons are made un-amped with my HP dv4t notebook computer using foobar2000 v1.1 and WASAPI in exclusive mode at 24-bit, 96 kHz. The notebook contains dual 3.5mm outputs so I can do simultaneous A/B testing. Portable sound assessments are made with an Apple iPod Touch 2nd Generation 8 GB un-amped.
The general sound of the HD381F is neutral, subtly mid-forward and bright, with deep and impactful but very controlled bass. The sound is spacious and transparent, although it may not sound as full-bodied as other IEMs.
In the context of putting them in the category of sub-$30 in-ears, the HD381F are absolutely the most revealing IEMs I've ever listened to. While their ability to resolve is nowhere near the level of top-end IEMs, they nevertheless compete with nearly all the sub-$100 headphones out there (that I've listened to). In a quiet room, the HD381F resolves more detail than a Klipsch Image S4, Audio-Technica CKS50/70/90, CKM55, and Shure SE115, just to name a few. The Etymōtic MC5 may possibly resolve marginally more mid-to-high frequency detail (listened to the MC5 a while ago, so I don’t remember clearly). Mind you, I haven't had the opportunity to test out some of the budget kings in this sub-$100 category such as the Hippos, ViSang/Brainwavz, RE0, etc. so the HD381F’s placement amongst them is unknown. If I had to take a gander, I'd say that even if the Superlux couldn’t resolve as well, it would surely still not be too far behind, as the HD381F are also able to handle and articulate the added resolution and dynamic range of 24-bit/96 kHz music, but sometimes does not take the high-resolution music to its full potential.
The strength of the HD381F's sound isn't at all in its resolving capabilities, however. We all know that resolution is not the key to an enjoyable music experience, but rather the cohesiveness in balance across the frequency range. In all honestly, the majority of Superlux products I’ve tried or bought have this property. The distribution between the lows, mids, and highs is so well balanced, that the only IEMs I’ve tried so far that have been as ‘euphonic’ as the HD381Fs have been the SE535 and the e-Q7 --- quite the elite company. Whatever resolution or distortion shortcomings the HD381Fs have is made up by the sonic presentation. It is for these reasons that the HD381F doesn’t feel boring, despite it not being full-bodied or super detailed in any frequency range.
At this point, if you’re still reading, you might be thinking, “Are you out of your mind? Really? $20? Better than top-tier IEMs?” --- No, that’s not at all what I’m saying. What I am saying is that Superlux managed to take bargain bin parts and tune it to its full potential, and that ceiling is as good of a sound package as I’ve ever heard.
Onto the negatives. Sonically, there really isn't anything to complain about, especially when you consider their price. The tuning is perhaps a little rough (not unexpected for the price) and it doesn't do well with poorly recorded material. It does best with lossless and higher resolution tracks, where the graininess is kept to a minimum.
While the HD381F isn’t a performer with respect to temporal output, it’s certainly very nice with spatial output. Since their design is more akin to an earbud than to an IEM, the HD381F imparts a much larger soundstage than most, almost on par with the IE8. The spaciousness of the HD381F isn’t surprising, however, since the semi-open design implies that it is airy. If I had to take a guess, the Phiaton PS210 would probably sound very similar with regard to the sound stage because of the extremely similar design and sound philosophy.
Unfortunately, it isn't able to convey three-dimensional space as accurately as full-sized cans, and that fact is not a surprise. While the instrumental separation is not bad, it doesn’t blow me away. When switching from full-sized headphones to the HD381Fs, the natural positioning of vocals is not rendered correctly, more often appearing right outside the ears than not.
On frequency tests, they hold good volume down to 40 Hz, with a nice drop-off down to 30 Hz (a sustained 30 Hz tone is easily heard and felt at normal listening volumes), and frequencies in the mid-20 Hz range can still be heard as well. On the high side, like most IEMs, it drops off sharply at 16 kHz, but holds the volume fairly well until that mark. Thus, we can safely say that the HD381F is well-extended on both ends of the spectrum with little roll-off until the extremes.
In an outside environment, the bass is a bit weak as the isolation on the HD381F is poor, but in quiet environments I would consider the bass to be decently strong. The impact may not satisfy the crudest of bass heads, but it doesn’t fail to render beautifully rich bass texture. After careful consideration, I'd say that the bass is best frequency range of these IEMs, by merit of its texture and dynamism, while never getting in the way of the midrange. The large 13.5mm drivers are probably the reason for its ability to produce nice bass, and I've always preferred dynamic drivers' ability to produce that natural, blooming attack and decay of very low frequencies. However, the bass speed isn't particularly anything to write home about, and I'd put it as average amongst most earphones.
The mids are slightly forward, but not too much, and aren't thick, so they may come across as slightly thin compared to lush, forward midranges of Shure, etc. I actually find the midrange of the HD381F to be very enjoyable, since it's not too forward but not at all laid back, so it fits seamlessly within the music. The one caveat is that the tuning of it is a bit rough, and lacks the type of refinement one might find in the products of other, larger brands. Give it sufficiently high resolution music and these problems go away, but typical music may make them sound a little 'rough around the edges' and louder listening volumes really highlight this fact, tending a little toward sibilance.
Perhaps the weakest part of the HD381F response range. It sounds fine in the grand scheme of things and carries a nice subtle sparkle to its upper frequencies, but complex treble passages will cause a little bit of distortion. Poorly mastered tracks also tend to exaggerate the HD381F’s distortion characteristics. These problems are mitigated partly by using Comply tips, which warm up the upper treble a bit. Since warm upper treble is my personal preference, this solution works great for me.
TRACK ANALYSIS BY GENRE
'Starstruck' - Lady Gaga feat. Flo Rida, Space Cowboy, The Fame Monster (V2 LAME MP3)
This Space Cowboy produced track begins with a great sub-bass line, and gradually creeps up into the mid-bass area, punctuated by synthesized organs. The HD381F does a great job of making everything sound clear and separated, but bass heads will feel underwhelmed by the impact of the bass. For everyone else, however, the bass impact will be plenty, especially for those coming from BA-based IEMs.
'First Love' - Utada Hikaru, First Love (320 CBR MP3)
The single that launched Hikki to stardom is a very nicely recorded track with a great natural sense of air. I have no idea how it was actually recorded, but it imparts the feel of a recording done in a large auditorium, similar to the style of early 90s pop ballads from the likes of Whitney Houston and Mariah Carey. The HD381F puts the right amount of air and reverberation into the vocals, which sound natural and detailed. By comparison, the Philips SHE9850, a much more forward-sounding earphone, sounds a bit artificial here as it fails to convey the proper sense of space with a compressed soundstage and, by consequence, unnaturally forward vocals.
'Forgotten Times' - Tsai Chin (FLAC)
By the way, if any of you want to listen to a quality vocalist for Mandarin music, Tsai Chin is the way to go. She's an oldie but a real goodie. If she got in the recording booth today with the best equipment, she'd give singers like Rebecca Pidgen a run for their money. A bit of trivia -- this song was prominently featured in the opening scene of the HK film 'Infernal Affairs', the movie from which Scorsese’s 'The Departed' was adapted. Tsai Chin begins the song acapella, and the undulations of her throat are heard clearly.
'Gee' - SNSD Girls' Generation (FLAC)
I had to test a 'modern day' track. To me, this song is the perfect example of modern Asian pop --- highly produced with vocals from questionable singers. The instrumental to 'Gee' is actually quite complex. Here, the naturally large soundstage of the HD381F comes through, while keeping the puposely forward vocals up front. The synthesized treble chimes are sweet and hold a nice, subtle sparkle. However, the HD381F fails to 'smooth out' things, and the squeaky clean pop sound we expect comes out as slightly grainy.
'Nuthin' But a G Thang' - Dr. Dre, The Chronic (320 CBR MP3)
Being a SoCal kid, I wholeheartedly embraced the Dre-perfected G-Funk sound in my adolescent years. This track also reminds us what hip-hop sounded like before studios began the loudness wars with ridiculous compression levels. The track is unabashedly blaze-tastic and I easily latched onto the bass guitar embellishments in the background. One criticism is that the synthetic violins come off as a bit texture-less, but I don’t know whether a technical deficiency of the IEM caused it or it was a natural element of the recording.
‘I Need a Dollar’ - Aloe Blacc, Good Things (FLAC)
I thoroughly enjoyed the trumpets on this track, but the piano and kick drum were rendered a bit too politely, a likely byproduct of the HD381F’s aspirations as a neutral monitor. Vocals and bass guitar were realistic and lively.
'I've Grown Accustomed to His Face' - Diana Krall, Quiet Nights (HDTracks, 24/96 FLAC)
Krall's Quiet Nights CD has a reputation as one of the best recorded and mastered albums to come out in the last few years, and its quality does indeed shine through with the HD381F, especially through the high resolution HDTracks version. Right from the intro, I could hear the subtle piano pedals articulating realistically. Krall’s breathy voice is clear and each breath has the requisite air. It’s a beautiful, subtle track and the HD381F does a decent job of making it feel transparent yet intimate.
'Les Eaux de Mars' - Stacey Kent, Raconte-Moi (FLAC)
This French re-imagination of Jobim’s ‘Waters of March’ is a lively, upbeat track and the CD master has an seemingly artificially boosted low-end, but the HD381F never causes that bloomy bass to bloat and get in the way of Kent's sweet voice. There's enough instrument separation to hear the strings on the guitar very clearly, as well as the bass string vibration. The gentle cymbal report decays nicely.
'I Wouldn't Need You' - Norah Jones, The Fall (FLAC)
Okay, I know that technically Norah's music doesn't fit in this category, but her reputation as a vocalist is in concert with the others. There’s a very low level electronic hum in the background that can be heard through BA-based IEMs, but with the HD381F the hum is very subtle. The lack of this detail is made up by a very nice rendition of the bass in this song, which has a fullness that only dynamic IEMs can fully realize. The higher undulating notes are clearly separated from the bass but lacks in resolution. Jones’ voice tends to get a little sibilant at times during the song.
'Flamenco Sketches' - Miles Davis, Kind of Blue 50th Anniversary Collectors’ Edition (FLAC)
Maintaining the absolute purity of Davis’ trumpet notes was a little bit of a trouble for the HD381F, but the slight distortion didn’t bother me too much (maybe I’m not as big a Jazz enthusiast as I thought) and there was still enough palpable texture in each note to feel real. As per usual, the bass notes were great.
'Doralice' - Joao Gilberto, Getz/Gilberto (24/96 FLAC)
I prefer this song over some of the more famous tracks off this album because of its upbeat nature. The clarity is great; with the high-resolution original master file, I could hear the subtle crescendo/decrescendo of the hi-hat from the drums, which was a great delight. Everything also doesn’t sound too rushed, as it may feel with other remastered versions because of the compressed instrument space, but this credit goes to the 24-bit file.
'Symphonie Espagnole, Op. 21' - Eduard Lalo, Performed by: Anne-Sophie Mutter (320 CBR MP3)
The first movement of this 'symphony for violin' was one of the signature pieces in my own solo repertoire, so I know it inside and out. The brightness of Mutter's 'Emiliani' Stradivarius is apparent even on this relatively dark solo piece. Mutter does a great job of making immediate transitions from the harsh scratchy sound (necessary for this piece) to sweet smoothness, and the HD381F reproduces these changes perfectly. It does lack a bit of resolution at times when compared to BA-based IEMs, not that it really matters all that much for this track, since it was one of the old ones Mutter recorded with Seiji Ozawa and the French National Orchestra. The orchestrals of Symphonie Espagnole tend to sound very murky on-stage or off, so the HD381F actually does an admirable job of conducing transparency. While the presentation of soundstage was okay, it wasn't nearly as wide or as realistic when compared to the full-size HD668B (not a surprise). Assessment of instrument separation was not really possible with this recording.
'Zigeunerweisen AKA Gypsy Airs' - Pablo Sarasate, Performed by: Gil Shaham (320 CBR MP3)
I've been a fan of Gil Shaham and his ability to phrase passages for quite a while now, and Zigeunerweisen is the best piece to assess a headphone’s ability to render the pure grit needed play this song. This is not a piece where one lets the bow sing; even on the light passages, this is a piece that requires precise bow control to distribute even pressure across the length of the bow but heavy pressure at the ends. I could hear all this with the HD381F (that is not to say that other IEMs cannot do the same). The one criticism I have is the vibrato texture; it is slightly lacking and I suspect that a BA IEM may do better, or at least a faster tuned dynamic driver IEM.
This is a side note regarding how I listen to classical music -- I listen almost exclusively to violin music, as I trained for nearly 15 years as a classical violinist and am most familiar with the sonic nuances of that instrument. With orchestral pieces, I prefer the onstage feel. I'm not the biggest fan of listening to classical music from the audience's perspective. I spent ten years in various orchestras ranging from amateur to professional, and the most involving part of being a classical musician is the feel of immensity emanating from all sides as the cymbals crash and the tympani is rumbling behind you. I had the honor of being second chair violinist as well as concertmaster for quite a few years and thus had a listening perspective very similar to that of the conductor. Thus, my sonic preferences with regard to listening to classical music might differ from others’.
All I can say is that I’ve never quite had an earphone that has wowed me this much. The HD381F blends the different frequencies together in such a harmonious manner that I always forget I’m listening to $19 earphones that ultimately don’t have the technical proficiency to measure up to the elite IEMs. While A/B-ing them with the UM3x, I had to always listen for specific things in the music to find the small elements of the UM3x that were invariably superior to HD381F. While the UM3x was highly detailed and imparted a great sense of intimacy, it often didn’t engage me to the music as well as the HD381F often does. I often switch between the HD381F and the Philips SHE9850 that I use during my commute, and while the sound of the SHE9850 is more dynamic and may grab a listener at the onset, switching between it and the HD381F highlights the deficiencies of the SHE9850, in particular its lack of proper treble, its artificial-sounding bass, and its tendency to be a bit too mid-forward (for my tastes).
These facts say a lot about the way the HD381F presents its music. While I have other options for listening these days, I come back to the HD381F for quiet room listening. In a quiet room, it’s detailed enough, and the distortion that it has in various parts of the frequency spectrum is small enough to ignore. Best of all, the semi-open nature of the phones precludes the need for me to equalize ear pressure and imparts a sense of a wide soundstage, a quality rare in most IEMs. You really can’t go wrong with the sound; it caters to analytical listeners but won’t alienate mid-centrists or even bass heads (okay, only if you’re not the type that requires head-rumbling bass).
For those of you who might think I might’ve gone off my rocker for holding a pair of $20 IEMs in such high esteem, I took a long time writing this review, listening to as many different IEMs as I could, to make sure what I was writing could hold up under the microscope. I’ve hit just about every single top-tier IEM there is (save for the RE0/ZERO/262, ER4P/S, and GR8/10, and the ridiculous Final Audio offerings), and while I may like some of them better (my favorites thus far are the UM3x, SE535, and e-Q7 in no particular order), there’s a certain charm about these cheapies that I stick in my ear every day and if a pair of $100+ IEMs don’t achieve a sonic balance close to the HD381Fs, I know they’re not worth my money.
Most of the gripes any owner will have with these earphones are in the areas of build quality, isolation, and ergonomics. These elements are still extremely important in the selection of a good IEM, and because of its poor build quality, I can't recommend these earphones for daily use as the primary IEM; I'm also well aware that Superlux products are difficult to obtain outside of Asia, but If any of you ever come around these parts, pick up a pair just because they're so cheap. Then you, like I have countless times, can drop your jaws and say flat out, "I can't believe I got this for less than $20!" They're that good.
Superlux HD381F In-Ear Headphones (IEM)
Comparable IEMs in Design: Sony MDR-EX90LP, Phiaton PS210
- Great, Cohesive Sonic Presentation, Neutral Response But Never Boring
- Wide Soundstage
- Decent Bass Extension and Presence
- Forward, But Natural Mid-Range
- Cheap (Price)
- Treble Distorts at Higher Volumes
- Vocals Subject to Source-Dependent Harshness and Distortion
- Vocal Sibilance is Grating at Higher Volumes (Goes Away with Sufficient Burn-In)
- Sub-Par Build Quality (Cheap Plastic, Non-Functional Strain Reliefs, Driver Flex)
- Semi-Open Design is Bad for Isolation
- Fit Can Get Uncomfortable Over Time