DUNU x KOTO ITO 2DD + 2BA IEMs Review
A quad-driver hybrid IEM with two dynamic drivers and two balanced armatures, listed at $189.99 with 37Ω@1kHz, 105dB/mW and a stated 6.5g per side. It suits buyers who want swappable 3.5mm and 4.4mm plugs on a 4-core cable.

Our verdict
Meant for buyers who want a two-dynamic, two-armature hybrid IEM at $189.99 with listed impedance, sensitivity, frequency range and weight and both 3.5mm and 4.4mm plugs. Look elsewhere if you want a planar driver or a measurement from someone other than the store. The main caveat is that the tuning story, including the five revisions the page describes, is the page's own account.
- Best for
- Buyers wanting a two-dynamic, two-armature hybrid IEM with swappable 3.5mm and 4.4mm plugs.
- Skip if
- You want a planar driver or an outside measurement of the tuning.
Why 3.5/5: Held down by terms across the store's own pages that contradict each other, and by every figure resting on the store's page because no independent test of this model was checked for this review.
DUNU x KOTO ITO is DUNU's collaboration model with the Japanese headphone content creator Kaji Kaji (Koto), per the page. It combines two dynamic drivers, a 10mm and an 8mm, with two balanced armatures, and is listed at $189.99. The specification section gives 37Ω@1kHz, 105dB/mW, 5Hz~40kHz and 6.5g per side.
Specifications
| Spec | Page says |
|---|---|
| Drivers | 2DD+2BA hybrid, quad-driver |
| Dynamic drivers | 10mm composite bio-diaphragm + 8mm composite LCP diaphragm |
| Balanced armatures | Two customized |
| Impedance | 37Ω@1kHz |
| Sensitivity | 105dB/mW |
| Frequency response range | 5Hz~40kHz |
| THD+N | Under 0.5%@1kHz |
| Weight | 6.5g per side |
| Cable | 4-core silver-plated single-crystal copper, 22AWG Litz braided |
| Plug system | Patented Q-Lock Quick Switch; 3.5mm and 4.4mm plugs included |
Options and pricing
One option, named ITO, is listed at $189.99 and was orderable when the page was read; the page shows a crossed-out price of $199.99 next to it. The page says the package includes a 3.5mm single-ended and a 4.4mm balanced plug on DUNU's patented Q-Lock Quick Switch system, and its feature list names three types of silicone ear tips. The page text gives no ear tip count, case or cable length.
How it compares
The AFUL MiracleOne 6mm LSR Diaphragm Dynamic Driver IEMs are also $189.99 and use a single dynamic driver by their spec line, where the ITO has two dynamic drivers and two armatures. The JUZEAR UNVEIL Series Light Shuttle Vocal-Focused Tribrid IEMs start at $184.99 with 1DD+4BA+2 Micro Planar per side, and the TRN Mermaid 1DD+1BA+2Planar Drivers In-Ear Monitor starts at $199.99 with a dual planar hybrid. The ITO suits buyers who want a dynamic-and-armature set; the Light Shuttle and Mermaid suit those who want planar drivers.
Shipping, returns and warranty
HiFiGO sells from hifigo.com and says every order leaves its warehouse in China, usually 1-3 business days after it is placed, and says its delivery times are estimates, not promises. Its shipping policy gives the United States 1-2 weeks (about 10 days on average) by Priority and 6-10 days by Premium, both with duties and taxes prepaid by the store; Canada 2-3 weeks; the United Kingdom 1-2 weeks; and Australia 10-15 days. Express couriers (DHL, UPS, FedEx) take 3-7 days, but then the buyer pays any duties and taxes. No shipping page names New Zealand, PO boxes are not accepted, and the free-shipping thresholds differ between the store's own pages, so check the cart. One of its two shipping pages adds that a lost parcel on an order above $50 gets only a 50% refund. A US buyer reported a $40 tariff charge in August 2025, after which HiFiGO said it had added a customs notice at checkout.
Read the return terms before you order. The homepage advertises 7-day returns. Both of HiFiGO's policy pages offer a 7-day dead-on-arrival cover (a replacement or a full refund, with the return postage refunded) and also describe 30-day returns, but a request made 7 to 30 days after delivery loses 30% of the MSRP as a restocking fee (10% more if the packaging is incomplete), plus shipping both ways and duties, and the FAQ on the same pages says there is no refund or exchange once 7 days have passed. One version recommends reselling an opened product locally. Custom IEMs and custom cables cannot be returned, no return address is published, and buyers describe sending items back to China.
HiFiGO's warranty runs one year from the order date for parts and labor; its policy names desktop DACs and amps, IEMs and dongles at one year and gives cables and adapters three months. HiFiGO decides between repair and replacement, the buyer pays the shipping, and faulty items go back for service, not for a refund. Claims go to [email protected], the only contact the store lists: its pages name no company, street address or phone, and its terms are governed by the laws of China.
On Trustpilot, HiFiGO had 4.6 out of 5 from 378 reviews when we checked on 2026-10-28 (91% five-star, 5% one-star), and it had replied to about 75% of negative reviews; Trustpilot notes the store has not invited customers to review recently. The one-star reviews mostly concern the short return window and the deductions on returns, items listed in stock that turned out back-ordered, slow email support and a tariff charge on a US delivery in 2025. HiFiGO says its products are genuine and come in the brands' retail packaging; it does not claim to be an authorized dealer.
What we liked
- Two dynamic drivers (10mm composite bio-diaphragm and 8mm composite LCP diaphragm) plus two balanced armatures, per the page
- Specification section lists 37Ω@1kHz, 105dB/mW, 5Hz~40kHz and THD+N under 0.5%@1kHz
- Sensitivity names its mW reference, and impedance and THD+N name a 1kHz test point
- Weight of 6.5g per side is stated
- Q-Lock Quick Switch plug system with both 3.5mm and 4.4mm plugs included
Worth noting
- The page text gives no connector type at the earphone end of the cable
- The page text gives no case or cable length, and no count for the three ear tip types
- The page text gives no graph behind its tuning descriptions or the store's Bassy Sound and U-Shaped Tuning tags
Questions before you buy
What drivers does the DUNU x KOTO ITO use?
The page lists two dynamic drivers, a 10mm composite bio-diaphragm unit and an 8mm composite LCP diaphragm unit, plus two customized balanced armature drivers.
What are the ITO's impedance and sensitivity?
The specification section gives 37Ω@1kHz impedance and 105dB/mW sensitivity, with a 5Hz~40kHz frequency response range and THD+N under 0.5%@1kHz.
Which plugs and cable are included?
The page describes a 4-core silver-plated single-crystal copper cable in a 22AWG Litz braid with DUNU's patented Q-Lock Quick Switch interchangeable plugs, and says both a 3.5mm single-ended and a 4.4mm balanced plug are included.
Where does HiFiGO ship from, and how long does it take?
From its warehouse in China, usually 1-3 business days after the order. The shipping policy gives 1-2 weeks to the US by Priority (6-10 days by Premium), both with duties and taxes prepaid, 2-3 weeks to Canada, 1-2 weeks to the UK and 10-15 days to Australia. Express couriers take 3-7 days, but the buyer pays any duties.
Can I send it back if I change my mind?
HiFiGO gives 7 days to report an item that arrives dead, damaged or wrong. Its policy also describes 30-day returns, but requests 7 to 30 days after delivery lose 30% of the MSRP plus shipping both ways and duties, and the FAQ on the same page says no refund or exchange after 7 days. Ask [email protected] before you open the box.
What warranty does HiFiGO give?
One year from the order date for parts and labor, for faults in build or materials (the policy names desktop DACs and amps, IEMs and dongles; cables and adapters get three months). HiFiGO chooses repair or replacement, the buyer pays the shipping, and a faulty item is serviced rather than refunded. Claims go to [email protected].
Sources & verification
What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.
From the store
- DUNU x KOTO ITO 2DD+2BA Hybrid Drivers IEMs product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead October 28, 2026
- HiFiGO shipping policyShips from China in 1-3 business days; US 1-2 weeks by Priority or 6-10 days by Premium, duties prepaid; Express buyers pay dutiesRead October 28, 2026
- HiFiGO shipping and order tracking pageA second shipping text: Premium also for Canada and Australia, Canada free shipping from $99.99, lost-parcel rulesRead October 28, 2026
- HiFiGO refund policy7-day dead-on-arrival cover; 30-day returns minus a 30% restocking fee; its FAQ says no refund after 7 daysRead October 28, 2026
- HiFiGO warranty and refund policyWarranty by product class (1 year; cables and adapters 3 months); 30% fee for resealing an opened productRead October 28, 2026
- HiFiGO terms of serviceOperator named only as HiFiGo; governed by the laws of China; contact [email protected]Read October 28, 2026
Independent
- HiFiGO reviews on Trustpilot4.6 of 5 from 378 reviews (91% five-star, 5% one-star); the store has not invited reviews recentlyRead October 28, 2026
What we couldn’t verify
- The page calls the tuning suited to different genres in the feature list and to rhythm-driven genres such as rock, hip-hop and electronic in the text; the store's tags read Bassy Sound and U-Shaped Tuning; the page text gives no graph.
- The page says HiFiGO started the collaboration with DUNU and Kaji Kaji and that the plan began in November 2024 and tuning went through five revisions across six months; the page text gives no records of those revisions.
- HiFiGO's policy pages contradict each other: 30-day returns with a 30% restocking fee in one place, no refund or exchange after 7 days in the FAQ.
- HiFiGO's pages name no company, street address or phone number; the only contact given is [email protected].
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