1Custom Junior

General Information

  • Customizable sound with tuning DIP switches
  • No. of Drivers: 1 Dynamic Driver + 2 Balanced Armature
  • Connector: MMCX
  • Termination: 3.5mm Stereo




Custom Tuning:

  • 1Custom Junior Drivers 1 pair
  • MMCX Cable x 1
  • Eartips (S/M/L) x 1 pair
  • Cleaning Tool x 1
  • Carrying Case x 1

Latest reviews

Pros: Crisp and forward Mids
Crisp and Detailed Highs
Punchy bass
Clean background
Cons: Low notes lacking a bit of weight
Fit (for my right ear only)
1Custom Junior: Junior Wonder

I got the 1Custom Junior for review from Nihal. I am sharing my unbiased opinion here.

Right from the start, it felt...good. really really good. So good that I can't put it off from my ears. I’ll try to categorise my impressions rather than simply rambling on.

No, it has not got rumbling bass that rolls around and grab your collar to get in your face. The midbass is punchy, although slightly behind the mids, subbass is only there in the background, surfacing only when it’s called upon and staying out of the way for the rest of the time. Very much detailed and cleanly represented.
Bassheads won’t love it. I would not have preferred it too, if not for the…

Yes, mids. Insanely beautiful mids. I can’t stop listening to music because of them. Such beautifully brought forward warm and alive mids. Vocals sound emotional, snare sounds just too damn detailed and real. String instruments - alive. Each different spectrum cleanly represented. And even though the mids are so forward the soundstage does not seem intimate - incredible tuning!
And what makes me even more incredulous at the tuning is...

I have not listened to treble this beautiful till date. It’s brought forward nicely but not at all sibilant or overly sharp. The only term that can define them is crisp, but not at all cold. Every little bit is gently presented such that you can hear the most obscured details vividly, without a single wince. It’s got plenty air too.

Soundstage and separation:
Expansive soundstage with good width and depth. Very good separation enhances the listening experience.

Track-wise impressions:
In the track Steven Wilson - Pariah (ft. Ninet Tayeb) there is a beautiful bassline at the last quarter, which if the bass is strong ruins the rest of the wide spectrum. Junior blends the bassline so beautifully that you can hear them and yet the rest of the track is not overshadowed by it.
Moreover, at the beginning of the track there is a very soft high note (probably triangle, I’m not so well-versed in recognising instruments) that other iems struggled to represent, while Junior brought it out vividly. I was so amazed that I had to re-check it repeatedly that if I was indeed hearing right. While this may be an indication how forward the treble is, what amazed me that how absolutely not piercing it is. Marvellous is the only word I have.

Disturbed - Ten Thousand Fist and Muse - Showbiz are 2 tracks that I use to check the sound separation and harsh treble. Junior handles these 2 tracks perfectly. Ten thousand fists is quite a busy track that sound not a bit of congested. Showbiz is another busy track with quite harsh treble that may give the listener a hard time if the iem produces sharp treble. On Junior it’s an absolutely quality time listening to the song, rocking to the tune. And also, no congestion at all.

Bear Mccreary - Battlestar Galactica Season 2 - Prelude to the war is a track for checking subbass, midrange and treble. On Junior the drum rumbles stay where they should without covering the rest of the frequency. But most importantly, it’s the snare whose sound becomes vivid with lots of details, warm and crispy. Literally cannot have enough of them. The cymbal crashes are beautiful and not piercing.

To put it simply, I’m head over heels in love with this Small Wonder.. I might as well name it Vicki, the Small Wonder herself. It’s a shame that I have to let it go to the next reviewer. I really really wish to hold on to it just a little bit longer...may be until I lose my hearing...may be...
Pros: Good detailed sound for the price
Staging and imaging are fantastic
Fit is quite snug and comfortable
Overall quite a decent iem for its price
Cons: Some upper mids peak with the stock cable
I got the unit for the purpose of review only and is provided to me by JABEN Singapore, in return for my unbiased review.

Please note that I am not associated with JABEN by any means and my review is going to be my personal opinion about the IEM and not affected by JABEN by any means. You can buy a pair for yourself here.

Build Quality –
In terms of build quality, the pair is very nicely built, even though the earpieces are made up of plastic, the plastic is of great quality and you will feel it has a great built. The product feels well finished and build quality looks good enough.

The IEM has custom tuning buttons on the backside of both of the earpieces, which we can use to change the tuning a bit according to our taste and need for music which we will mention during the sound quality part discussion.

The earpieces are in the shape of earplugs and sit nicely in my ears, the fit is just outstanding, they just won’t fall out of your ears even while running or working out or whatsoever, please note that I prefer over-ear style for wearing my earpieces.

Sound Quality –
In terms of sound quality, I was really impressed by the details and smoothness of sound it produced. The Sound is actually U shaped with thumpy bass response, detailed mids and smooth treble response. There is no harshness of any kind to treble or any other frequency, the soundstage feels wide enough and there are good details in instruments being played.

One can easily recognize different instruments being played even in fast songs, the instrument separation really makes the sound feel brilliant.

Let’s discuss the different aspects of the sound frequency range.

Lows –
1Custom Junior has really good thumps and bass response, the amount of sub-bass is also adequate and one won’t be disappointed in terms of bass response.

And the best part is none of the basses overlap the details in mids, I tried the song Thriller by Michael Jackson and all the music details and vocals everything was clear with no background noise through my Hiby R6.

Mids –
Even though the tuning of sound is U shaped here, mids are so detailed and crisp one won’t feel them laid back by any means.

Vocal based songs like the Acoustic session by Boyce Avenue feel full with life and shine brilliantly here, Heartbreak Warfare by John Mayer is also a good listen here with amazing music and brilliant vocals. Blower’s Daughter by Damien Rice sounds very beautiful too.

Highs –
The treble response is well controlled and again well detailed here, Drums in Digital Bath by Deftones sound brilliant and mesmerizing here.

I am thoroughly impressed by the IEM’s response and music production, in Another brick in the Wall by Pink Floyd the music and vocals feel lively and forward.

There is no harshness or sibilance in the treble region, none of the music feels peaky or harsh to the ears.

Other songs which I tried –

Yosi Horikawa: Bubbles
The Who: Baba O’ Riley
Sara K: Miles Away
Tingvall Trio: Vattensaga
Brandt Brauer Frick Ensemble: Teufelsleiter
Radiohead (OK Computer): Exit Music (For a Film)
Funkadelic: Maggot Brain
Led Zeppelin: Since I’ve Been Loving You

Custom Tuning Switches –
There are several tuning options in the IEM’s available at the back of both the earpieces.

And a piece of cardboard is also enclosed with the package showing different tuning options available with the IEM.

To be very honest the tuning portion is just a mere gimmick and there is not much difference noticeable. This whole tuning is not required when the iem sounds already so great.

Soundstage and Instrument Separation –
Even though the earpieces are closed container design, the soundstage is adequately wide and enough for most of the songs, even for binaural tracks by Yosi Horikawa the soundstage feels amazing.

And thanks to the brilliant detailing of the IEM, the instrument separation is really good even for quick death metal songs by Death and Opeth.

Also, it’s closed container design, the earpieces seal the ears well and there is no noise leakage of any kind even on higher volumes and noise isolation is good too, you won’t be able to listen to your environment and will be enjoying your music easily.

Final Verdict –
1Custom Junior is a great value for its price. To me, it surpasses many iems easily, in its price bracket. I compared with different iems – Fiio FH5, Moondrop Kanas Pro, Campfire Audio Polaris and oBravo Cupid.

Give a nice cable to JR., and it will compete against many iems, way above its price. The peakiness in the upper mids goes away. The bass is more stable and clear. The instrument separation goes to a different level and the mids and lows start shining. It easily outperforms FH5, Kanas Pro and Polaris. And there I made a very bold statement. The bass is more sorted on JR. than in Polaris. Kanas Pro, which is a sweet-sounding iem does not match the details of JR. FH5’s heavy bass and highs are again not as smooth and detailed as the JR’s. To me, oBravo Cupid is still the next level monster. Nothing can beat it in its price range.

To me, JR is an instant favorite. I hope people do try it and see for themselves how worthy they are. I am very excited to try out the other high end iems from 1Custom.

EDIT: Here is the graph for those who'd be interested.

WhatsApp Image 2020-02-12 at 14.52.31.jpeg

PS: This is my first review. Thanks
Last edited:
@heyandrey - I have attached a graph with the review. Please check.
hi there. I am considering getting the 1 customer jr... how is the bass compared to iems like moondrop starfield... is it more punchy?
@johntay - Hey, I have not used Moondrop Starfield, but comparing the 1Custom Jr many other iems in the same range, I found it to have better bass. Its crisp, clear, and accurate. This will not disappoint you, is that what I can tell.


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