Open Audio MERCURY Hybrid IEMs Review

Open Audio's MERCURY is a five-driver hybrid in-ear monitor, which the page places in OpenAudio Studio's Element series, and HiFiGO lists it at $527.12. Each side pairs a 9.2mm PU soft suspending dynamic driver with four balanced armature drivers in a three-way crossover. The page gives 8Ω at 1kHz, 110dB SPL at 1mW and a 5Hz-40kHz range, and describes the cable as 4-core.

Specifications

Options and pricing

Two options are listed, MERCYRY-3.5mm and MERCYRY-4.4mm, spelled that way on the page, each $527.12 and orderable when the page was read. The page shows a crossed-out price of $599 next to $527.12. The names carry a 3.5mm or a 4.4mm size, but the page text does not say what it refers to and names no connector type or cable length.

How it compares

The Hidizs MS5 is $499 and its name counts 4BA+1DD in five units, the same dynamic-plus-four-armature count the MERCURY page lists at $527.12. The Moondrop METEOR is $549.99, with 1DD+2BA+4Planar in its spec line. The Softears EDGE is $499 and lists an 11mm dynamic driver. Pick the MERCURY for a hybrid with a size choice in its option names and an 8Ω figure on the page; pick the MS5 if its lower listed price matters more.

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.