REVIEW – Budget IEMs usually mean picking a lane, warm and muddy or bright and fatiguing, with not much room in between. The OLA II is a hybrid driver IEM that plugs straight into a USB-C port and runs its own onboard processing instead of leaving the tuning entirely to the driver hardware.
I recently reviewed the Kiwi Ears Cadenza II, another USB-C budget IEM sitting five dollars cheaper, and the two make an instructive pair. The Cadenza II puts everything into one very well behaved dynamic driver and asks you to like its tuning. The OLA II splits the work across two drivers and then hands you an equalizer. Those are different bets about what people shopping at this price actually want.
Note: This TANCHJIM OLA II was sent to me by TANCHJIM at no cost. They had no editorial input and did not see this review before it published.
Photos and video by Gregory Morley.
The Basics
The OLA II is a coaxial hybrid IEM, a 10mm dynamic driver and a balanced armature driver mounted on the same axis rather than side by side, which TANCHJIM’s marketing calls DMT5. This particular version terminates in USB-C instead of a standard 3.5mm jack, and that Type-C connector does more than swap the plug. It houses a DSP chip that unlocks an 8-band parametric EQ in the TANCHJIM app on Android, so the sound signature genuinely changes instead of the app simply riding the volume.
What You Get
- TANCHJIM OLA II earpieces (USB-C DSP version)
- Detachable USB-C cable
- Eartips, multiple sizes
- Carrying case
By the Numbers
- Price: $59.99
- Driver configuration: 10mm DMT5 dual-magnetic dual-chamber dynamic driver + PURE Hi balanced armature, coaxial hybrid
- Impedance: 30 ohms (±10%)
- Sensitivity: 121 dB/Vrms
- Frequency response: 8 Hz to 48 kHz
- Connector: USB-C with onboard DSP
- EQ: 8-band parametric EQ via the TANCHJIM app (Android)
Design & Build
The shells are small and rounded, shaped from a large sample of real ear-scan data according to TANCHJIM, and they sit in the ear without the sharp edges some budget IEMs still ship with. The faceplates have a plain, understated finish. The detachable cable uses a standard 2-pin connector at the earpiece end, so it’s replaceable if the USB-C end ever fails, without needing to replace the whole set.
Sound and the DSP
Straight out of the case with no EQ applied, the OLA II leans slightly warm, with dynamic driver bass that carries real weight without bleeding into the mids, and a balanced armature that keeps the top end present without turning harsh. On its own that would make a perfectly respectable sixty dollar IEM and not much of a story.
The story starts when you open the app. Pulling up the 8-band EQ turns these into a noticeably different pair depending on where you drag things, and being able to save tunings, so music and a late-night call don’t have to share one compromise, is something no 3.5mm version of the same shells can offer. The cost of that flexibility is an Android phone and the discipline to actually open the app.
Game EQ
Game EQ is the app’s second bank of presets, and it works differently from the manual editor. Instead of eight sliders you set yourself, you get a list of games, each one carrying a curve TANCHJIM built for it and an Apply button beside it. The tile for it sits on the hub screen between Official Presets and EQ Forum.
Valorant, Call of Duty Mobile, Genshin Impact, League of Legends Mobile, Naraka: Bladepoint and Delta Force: Hawk Ops are all in there, mixed in with a few others. Three tabs sort the list, Game, Tactical and Virtual, and a row of pills underneath lets you pick phone, PC or Switch. Tapping a title loads its curve in one step, where getting to the same place by hand means dragging eight sliders and second-guessing every one of them. Nothing locks it in either, so the manual editor still opens on top of whatever a preset just set.
What Could Be Better
The DSP and app EQ only work on Android, so on an iPhone the USB-C version loses its entire reason to exist and works as a plain wired pair with no EQ access. The eartip fit also runs slightly shallow next to some competitors at this price, so anyone who wants a deep seal should start with the largest included tip. Neither is a dealbreaker at $59.99, but both matter before you assume USB-C automatically buys more control than the 3.5mm version.
Watch the Review
Video review coming soon. The companion video is still in edit, and it will be embedded right here as soon as it goes up.
Quick Questions
Q: Does the EQ work on iPhone?
A: No. The onboard DSP and the TANCHJIM app’s 8-band EQ are Android-only. On iPhone, the USB-C version works as a plain wired pair with no EQ access.
Q: Is the cable replaceable?
A: Yes, it uses a standard 2-pin connector at the earpiece, so a damaged cable can be swapped without replacing the whole set.
Q: How does it sound without the EQ applied?
A: Slightly warm with real bass weight from the dynamic driver, balanced by a present but non-harsh top end from the balanced armature.
Q: Is the USB-C version worth it over 3.5mm or 4.4mm?
A: Only if you have an Android phone and will actually use the app’s EQ. Otherwise the 3.5mm version at a slightly lower price does the same acoustic job.
Final Thoughts
The OLA II earns its reputation on driver hardware alone, but the USB-C version’s real pitch is the app EQ, and that pitch only lands on Android. For the right phone it turns one pair of earbuds into several tunings without buying anything else. At $59.99 that is a lot of flexibility for five dollars more than a very good single-driver pair like the Cadenza II. For an iPhone, the 3.5mm version does the identical acoustic job for a little less money, DSP or not.
Price: $59.99
Where to buy: Amazon or Linsoul
What I like: Genuinely different tunings via the app EQ, not just a volume trick, per-game presets that apply in one tap, coaxial hybrid sound has real bass weight without losing top-end clarity, detachable 2-pin cable, small comfortable shells
What I don’t: DSP and EQ are Android-only, no benefit at all on iPhone, eartip fit runs a bit shallow for a deep seal
