In this article, I review the Tanchjim 4U IEM. The 4U is a single dynamic driver In-ear monitor (IEM) and comes with a bass tuning dial. It’s priced at $69.
Disclaimer: This sample was provided by HiFiGo for an honest review. All observations and opinions here are my own, based on my experience with the product.
Tanchjim 4U


Design
4U has zinc alloy shells with polished metal faceplates. While the faceplates look rather fancy, they quickly become covered in fingerprints and scratches. However, the shells are small and comfortable.
The included silver-plated copper cable looks great and handles well enough, although it tends to get tangled quite easily.
Switch Settings
There are 4 different sound profiles that you can cycle through using the tuning dial and the included screwdriver. The profiles are Atmospheric, Pop, Natural and Monitor and they just change the bass level in varying degrees. Atmospheric has the most bass and Monitor has the least. I stuck with Atmospheric and I think most people will likely choose that one too.

Sound
Gear used for testing includes the xDuoo Link2 Bal, HiBy R3 II and SMSL DO300EX. The 4U doesn’t require a powerful source but its dynamics open with beefier amplification.
The Tanchjim 4U is a sub-$100 master class in natural timbre. As I started listening, my initial reaction was that it reminded me of a common type of tuning that was popular 6-7 years ago before the graph revolution. With an emphasis on organic cohesiveness and musicality, the 4U steers clear of forced clarity or muted bass, aiming instead to make your music enjoyable.

Bass
The bass is full-bodied and textured, though not the most impactful, even in Atmospheric mode. However, it doesn’t need to be overwhelming for the notes to feel substantial. The 4U’s bass offers a lovely, warm tone with plenty of mid-bass punch and sufficient sub-bass depth to be engaging.
Midrange
The midrange sounds earthy and unforced. It’s not the utmost in clarity but it oozes naturalness and accurate timbre. Vocals are a highlight, rich yet articulate, vibrant yet never shouty. The same can be said for instruments – cellos have a deep resonance and pianos sound crisp but never sharp.
Treble
The treble has a safe tuning. It has a slightly warm presentation with a pleasing tone that’s free of sibilance and harshness. Despite a large dip in the upper treble, 4U’s detail retrieval is impressive and allows me to hear most micro-details. Although it’s not the airiest of trebles, the highs have good extension and density.
Comparisons
Kefine Delci ($59)

The Delci has more bass impact and depth, especially in the sub-bass where it can rumble when required. The mids and treble follow a similar curve to the 4U after the bass yet Delci has slightly better overall resolution and more precise imaging.
Twistura D-Major ($49)

D-Major has less bass on the graph but to my ears, it has better low-end extension and authority as well as more definition. D-Major’s mids are brighter and more forward, especially in the upper mids where they can be somewhat aggressive. The treble has more sparkle and vibrancy than the 4U. The Twistura has a wider soundstage and more precise imaging, however, the 4U has a more natural tone.
Verdict
The Tanchjim 4U is a pleasant IEM that on one hand, presents an engaging and natural sound but on the other has some questionable design choices and a gimmicky tuning dial. I think it’s still a solid option for the price but those seeking something with bass impact will be left wanting and those looking for multiple sound profiles may find the tuning system disappointing by its limitations.