Phonon SMB-01L

SMB-01L is the newest creation coming from the Japanese boutique manufacturer, Phonon. Although it is largely unknown to the general public, it is deeply respected & praised within the artist and professional musician communities thanks to its underground roots. Beside being trusted by many sound engineers and producers, Phonon’s SMB-02 has even made it to Depeche Mode’s 2013 live studio sessions. Need I say more?

After a widely successful Kickstarter campaign, the SMB-01L concept came to reality. For some reason, many people turn the page when they hear a product came from Kickstarter, and I don’t blame them. Many companies misuse the platform and do not deliver the product they promised. The story for Phonon is different. I asked Isao Kumano why he turned to Kickstarter, to which he replied, “Kickstarter was a good place to raise funds and sell our products because I don't have the contacts as a businessman”. The whole idea was to manufacture a headphone that would function like a pair of large [studio] monitors. This goal was achieved by using Foster Electrics MT050A 50mm bio-cellulose drivers.

Disclaimer: The SMB-01L has been provided to me free of charge. I am not affiliated with Phonon, am not receiving any monetary or other compensation for writing and publishing this review. The review is strictly based on my personal experience, and is free of bias from any external force (whether it be the manufacturer, others' opinions, or online influence). All my views and opinions are freely expressed.

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I did a little interview with Isao Kumano and Alex Prat, which you can read here.

Design​

Phonon’s professional audio background is apparent in the design department, as the SMB-01L looks like a pair of studio monitoring headphones. I can picture them camouflaging right into the studio environment with the all-black color scheme, the simplistic design, the integrated headband, and the rotating cups.

If you look at it from afar, it doesn’t look much special, but take a closer look and you will start to notice the details. For example, notice how the design is sharp on the outer side, and soft on the inner side of the headphones. If you look at the yoke and the headband construction, you will notice that the outer plastic pieces have bold lines and distinctly defined corners, whereas the plastic pieces on the inside soft and rounded off. This design language makes the face and the sides of the yoke pop, while the inner side simply compliments the whole headphone silhouette.

The ear-cups are very interestingly due to their soft shell shape. They almost look like an anchor, where you have that wide smiley base. This design makes the driver sit in an asymmetrical enclosure. To make matters even crazier, the upper half—which is flat—has 9 vented holes. However, these vents do not lead to the driver enclosure, because, as mentioned, the top half of it is missing. Instead, they lead to the inner side of the ear-cups, i.e. the area that the ear-pads cover. Of course, the main feature of the headphones is the switchable plate that lets you choose between a closed and a semi-open design. Once you take it off, you will find a felt-like pad with 7 holes, of which 3 are larger and 4 are smaller in size. If you decide to further explore the area and remove the pad, you will find yet another interesting feature, an internal grid.

Build Quality​

At $800, this headphone fits right under the premium consumer headphones branch. It’s not expensive enough to be appealing to only enthusiasts, and it’s not affordable enough to be considered by the masses. With more and more premium-built headphones coming to the market at increasingly affordable costs, the expectations from the more expensive headphones keep rising, as does the pressure of them meeting the adequate standards.

If there’s one area that can be improved on these headphones, it’s build quality. Even Isao himself acknowledged this, “We wanted to create headphones that would function like large monitors. We feel that we have achieved this in terms of sound quality, but we are still improving the durability of the product”. Some may see plastic as a negative indicator when quality is in question, but I’d argue against that. It all comes down to what plastic is being used. Many know about my admiration of the Sennheiser HD598, and one of the things I praise those headphones for is build quality. So much so that it’s my golden standard for plastic quality. The plastic used in them is top-notch. They are the reason why I am such a harsh critic when it comes to plastic. It’s hard to be tolerant of manufacturers who overlook their product’s build quality, especially if you acknowledge companies like iBasso and Aumkar Chandan’s Kaldas Research and Altiat, bothl of which challenged the whole industry by releasing ±$500 headphones with exceptional build quality.

Excluding the headband height adjustment and the backplates, the SMB-01L is fully made of plastic. What’s throwing it off is not the build quality per se, it’s rather finish of the plastic. When the surface of plastic is smooth, as it is on many headphones, it looks the best when it’s in matte or satin-like finish. Glossy and polished finishes are a topic of their own, but when the finish of a smooth plastic surface is shimmery (glittery), it gives it a cheap appearance, as is the case here.

And then there’s the pleather headband… It reminds me of HiFiMan, which is not a compliment!

I think that the pressure is extra high on Phonon due to its Japanese roots and because the SMB-01L came from a wildly successful Kickstarter campaign, but also because “Made in Japan” is a stamp of the highest quality standards. It is something that is praised around the world equally as much as it’s recognized as a symbol of pride in the Japanese culture. Quality-wise, I just wish that Phonon was more mindful of the material choice and the production side of things for its flagship model.

Cable​

On the brighter side of things, Phonon got it right with the cable. Back to basics, should I say. Everybody has their preferences, but I am at a point where I can confidently say that I am a rubber guy. I am not a big fan of fabric cables, and perhaps that’s because I haven’t yet come across a high-quality one yet. Over the years, I have been very vocal of my opinion on rubber cables, of which my favorite is the stock cable that comes with the Sennheiser HD598 headphones.

For a cable to be considered good by me, it needs to possess the following qualities [in no order]:

1. Durability
2. Flexibility
3. Lightweight
4. Thin
[Bonus]
5. Easy to put away
6. Nice finish

Durability is hard to determine without long-term use, but you can get a general idea by feeling out the cable.
Flexibility is a very important factor for me, because the last thing I want is to be fighting the cable. I like the cable to be formless, like water. Rubber braided cables do this the best.
The lighter the cable, the better. I do not want to feel the weight or the presence of the cable; it should be invisible.
Thickness is somewhat related to point 3. The cable should be invisible. I do not want to feel its presence, and there’s nothing worse than a bulky cable.
When I roll up the cable around my hand to put it away, it must hold its form and not tangle up or ‘explode’.
If the cable has nice sheathing, it can be appealing in appearance and pleasant to the touch. For example, standard (non-braided) rubber cables with a matte sheathing are considered premium by me (e.g. HD598’s cable).

I’m sure audiophiles and cable lovers want to choke me dead, and I am fine with that. The points above are the criteria that a cable has to meet in order to be considered good or great by me, and yes, it’s not about ‘sound performance’.

With all of this out of the way, SMB-01L’s cable checks all but point 5. It’s a well-made cable, and while not the prettiest, it certainly is a good rubber cable. The sheathing is a bit shinier than I prefer, and it’s not perfectly smooth (it’s wrinkly). However, it’s the premium housings that make it stand out as a great cable. On the headphone end, there is a slim TRRS 3.5mm connector, which has a slim metal housing with two textured grip rings, and Phonon’s logo in a golden finish. On the amp end, there is a bulkier housing that’s also made of metal. Unlike the headphone end housing, which is black, the housing here is in a stunning silver mirror-like finish. I’m usually against mirror finishes due to them being fingerprint magnets, but that’s not the case here. The housing manages to retain the mirror-like look by being very shiny. Although fingerprints are visible, they are immediately noticeable and can only seen up-close.

Comfort & fit​

Another field the SMB-01L got right is comfort. It’s hard to screw up comfort with velour or suede, but it requires a lot of effort to achieve comfort with leather. For this reason, I am happy to report that the sheepskin leather pads are quite comfy. There’s nothing really to complain about, as Phonon followed all the necessary steps to make a comfortable set of headphones. The headphones don’t even get too hot after long listening sessions, which is a common issue with leather pads. I can only assume that this is due to the vents on the ear-cups, but also due to the vented ear-pads. Allow me to clarify. The ear-pads themselves don’t use a perforated design, but they do feature large holes on the bottom, and this can be felt if you run your finger on the inner-lip of the pads. Thanks to the firm clamp force, you don’t have to worry about the headphones falling off your head during your intimate head-banging sessions. In addition, the ear-cups have 90˚ of swivel and pivot rotation, allowing them to adjust to anybody’s head. It’s got it all!

While I can agree that the materials of the headband and the ear-pads are nothing extraordinary, the versatility of the circular ear-cups makes up for it. I am talking about the compatibility with after-market ear-pads. So far, I only had a chance to test iBasso’s SR2 pads and Dekoni’s Elite Hybrid (for Fostex TH and Denon AH series). My review is based on the performance with the stock pads, although Dekoni’s pads are the ones I’m privately enjoying the most due to their comfort. I couldn’t resist the coziness! The best part of all is that I can switch the pads in less than half a minute.

Sound Performance​

Lows​

After listening to electronic music classic albums such as Justice’s “Cross”, Giorgio Moroder’s “From Here To Eternity… And Back”, Burial’s “Untrue”, I realized that this is Phonon’s territory. Considering the company’s electronic music background, it would be quite awkward if the SMB-01L didn’t perform well in this field. What stands out above rest in the lows region is how controlled they are. Making a headphone with boomy bass isn’t that challenging. What is, is creating a headphone that has elevated bass, but retains full control of it. In fact, the first thing that caught my attention when first listening to these headphones, was the transient speed of the lows. In some headphones, the transient speed can be almost analytical, with the lows always sounding very punchy and articulate, on the SMB-01L, it only sounds like that when needed. I found this to be beneficial, because maybe you don’t always want the bass to be aggressive and “defined in your face”.

Let’s talk about the performance with my two standard test tracks, “Hydrogen” by MOON, and “Smoking Mirrors” by Lee Curtiss. In the first track, we can hear the previously-mentioned transient speed, whereas in the latter track, there is a greater volume and thud to the kick. Regarding the mid-bass, something that I heard in various other tracks is how the bass is impressively voluminous and deep. When you combine all these characteristics, you get a very clean and thick bass response, which is something that’s desirable in a lot of different fields and genres of music.

Sub-bass though, is something else. I see it as the headphone’s strongest trait. It absolutely smashes the performance in Hans Zimmer’s “Why So Serious?” (3:26 minute mark), with the sub-bass having great presence whilst remaining clean and under control. It pulsates in your ear, and it hits the sweet spot at the deepest lows. The same can be heard in Robbie Robertson’s “Theme for The Irishman”, where the SMB-01L perfectly keeps up with the depth of the cello and the drums. It doesn’t growl or shake your head, but it fills your ears with this bold mass of bass volume. This same volume can be heard in the introduction of Arctic Monkey’s “Do I Wanna Know?”.

Mids​

Generally speaking, the mid-range is safely tuned. If you are listening to any modern music, I doubt you’ll come across a track that will sound bothersome with these. However, it should be said that the great deep low end extends into the mids, often giving vocals that oomph. This is especially audible in “audiophile” tracks, which usually have intense and forward vocals. Yao Si Ting’s “Speak Softly, Love” can be taken as an example. On one hand, it makes instruments sound great and gives them depth, but on the other, it hurts vocals. The good news is that it’s not extreme to the point where vocals sound bloated.

Even though this is a V-shaped headphone, the mid-range is pretty decent. There’s no funny business going on. It doesn’t sound too thin, it doesn’t sound too thick, there’s no odd tonality, it just sounds decent. Just like there are no negative qualities, there are no miracles either. Usually, the only time when things got problematic was in poorly recorded tracks. Whereas the mid-range is mostly tame with no particular part of it sticking out, in essy tracks and vinyl rips, peaks considerably stick out in the mix. This quality is audible in Joan Baez’s “Babe I’m Gonna Leave You”, Sia’s “Elastic Heart (Piano Version)”, Yao Is Ting’s “Speak Softly, Love”, and tracks alike. When I mention vinyl rips, I am referring to the crackling that’s ‘usually’ audible. That’s about the only time when you will hear this headphone sounding hot in the mids. Other than that, the mid-range is safely tuned.

On a more positive note, strings sound very nice. This is one area where that bottom-end extension comes in very handy. Each string pluck has weight and can be felt, and that’s a quality I am always after when it comes to strings. I particularly love listening to acoustic stringed instruments, and when the bottom-end is missing, the timbre is a complete miss. Without the weight, instruments tend to sound digital and electronic to my ears. In other words, they lack the very acoustic qualities that set them apart from digital instruments. Fortunately, my ears were quite happy listening to Deep Purple’s “Soldier of Fortune”, Pink Floyd’s “Hey You”, and Yao Is Ting’s “One More Time”, where the fine nuance of the acoustic strings is captured spot-on by the SMB-01L.

Highs​

Finally, we’ve made it to my favorite part of this headphone—treble.

I’m usually the type of pal that likes the top-end to be sharp and clean, and am a big sparkle junkie. As long as it’s done well, it’s something I can appreciate in any headphone. It’s sharp enough when my ears tingle from it, that’s my my rule of thumb for treble.

Much like the mids, there is a “safe” roll-off, meaning that you won’t have to worry about any sharp peaks piercing your ears. In fact, I went through just about every track I would otherwise use to test whether a headphone has a great treble extension, and in none of these tracks did I hear any sign of brightness or sharpness. Among those tracks are: Miles Davis’ “Portia”, Sia’s “Chandelier (Piano Version” (chorus), “Elastic Heart (Piano Version)” (2nd verse, 2nd & 3rd chorus, outro), Travis Scott’s “Stop Trying to Be God” (Stevie Wonder’s mouth harmonica 4:43 - 5:43), and of course, Jeff Healey’s cover “Blue Jean Blues” (electric guitar 4:13 - 5:06). At most, SMB-01L reaches “shine” level of treble (sibilance>sparkle>shine>sheen>warm), and it takes quite a lot to push it to that measure.

If there’s no sparkle, how come this is my favorite part? It all comes down to the unique tuning present at the upper-end. The edge and the energy are in percussion, which might be the first time I’ve come across such tuning. Not only did I appreciate it, I full-on enjoy it! The conclusion I drew from this experience is that I’m after sparkle, no matter where it is—a true sparkle junkie.

When I say “percussion”, think cymbals, hi-hats, triangles, etc.. Whether it’s Russian Circles, Daft Punk, or Led Zeppelin, no matter the genre or the quality of the tracks, the treble in the percussion department never disappoints. It’s always crispy and it pops. The very first time the SMB-01L surprised me with its treble is in one of my standard bass test tracks, MOON’s “Hydrogen”. After the introduction settles in, around the 00:46 minute mark, I never heard the clicking so distinctly. It was as if I was listening to the song for the first time in my life. It’s odd, but it’s quite a joy exploring music with the percussion in the foreground.

Closed-back vs Semi-open​

Why limit yourself to one when you can have both?

The first thing you will notice when switching between the two is sound isolation. As soon as you go with the semi-open plates, you will be back to reality. The closed-back plates don’t give you vacuum-like isolation, and that doesn’t come off as surprising considering how well-vented these are.

While sound does get affected, it’s not to the extent that some may have expected. Consider it more as fine-tuning than completely switching things up. What the two backplates allow you to do is tweak the tuning, rather than altering the whole character of the headphones. If you want a more immersive sound experience, you can pop the closed-back plates. If you want to lay back and relax, you can go with the semi-open plates. The latter tone down the lows, make the mids more voluminous, and expand the soundstage. What’s most awarding when switching back between these plates are technical details. I already mentioned how the soundstage opens up, but separation and detail retrieval are two other areas where the semi-open plates have the upper edge on.

Conclusion​

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The SMB-01L is a headphone with tons of potential. If you’re a crafty person who loves DIY modding, I think it’s the dream for just that. One of the easiest and most accessible mods are the ear-pads. The circular shape of the ear-cups allows it to be compatible with the majority of the aftermarket pads, as long as you get the sizing right! The backplate is the second step. You can experiment with an endless number of materials, thicknesses, and hole shapes. The same can be done with dampening materials and the space below the plate. You can go to the extremes, if you wish. This would include removing the internal metal grid and completely playing around with all the empty space in the housing. The potential is definitely there, but whether you are willing to dedicate your time to utilize it is entirely up to you. The possibilities and combinations of what you can do to this headphone are infinite, it’s just a matter of how passionate you are about it.

It’s an exceptional fun-sounding headphone even in its stock form. The detail retrieval is on another level! I used the iBasso DX300 MAX for the critical listening. Considered to be a “reference” DAP, it does not color or correct imperfections, but instead emphasizes them. I found the iBasso DX320 + AMP11Mk1 to be the only combination that toned down the ‘popping’ peaks, making it the warmest option. Options, you have a lot of those with these headphones. My favorite part of the SMB-01L comes down to how you get to experience familiar tracks for the first time all over again. This is a headphone that is meant for jamming to music!

Saving the best for last...​

After much effort and back-and-forth, I was able to convince Phonon to do something special for you. First of all, I want to say that I am very thankful to the whole Phonon team for granting my wish! Exclusive to my Head-Fi readers, you can now get the SMB-01L for ¥52500* (25% off Japan retail price, ¥70000). That's over 50% off global retail price! To apply the discount, email the code "voja" to info@phonon-inc.com.

*Excluding VAT, customs fees, and shipping costs.
Please note that the discount is not applicable for orders from the European or US warehouses. All orders will be shipped exclusively from Japan, with worldwide shipping available.

Update (13.6.23): The discount has ended.