1Custom Junior – The New Detail King!

Recently when I visited Jaben Store in Singapore, the much-beloved Uncle Wilson provided me a unit of a new triple driver IEM to review. When I used the IEM for the very first time, I was left awestruck with the quality of sound. After spending a good amount of time I am so mesmerized by the details the iem renders.

This new iem is 1Custom Junior. It is a triple driver hybrid IEM with 1DD and 2BA configuration where the earpieces have MMCX connection.

The main highlight of this bud is it has custom tuning switches at the back of both the earpieces which you can use to switch the tuning profile as per your need and taste.


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 to be comparable to those of IEM’s like the Moondrop Kanas pro despite being whole plastic body.

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.

I personally tried all the three options available for tuning, and to my ears, the sound tuning change is around 5% from the original sound.

When I tuned for bass response, the bass increase was not much or overpowering than the basic tuning from the bud and hardly a 4-5% increase in the depths of thumps.

Similarly when I tuned for vocals or details the overall increase in the said department was around 4-5%, but overall the IEM’s basically is brilliantly detailed in every department.

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 silver cable to JR., and it will kick out most of the iems from the room. 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 much smooth and detailed as the JR’s. 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.


Picture courtesy: My friend’s Website