Fosi Audio IM4
- 1 review
- Fosi Audio
Fosi Audio IM4
- 1 review
- Fosi Audio
$119.00
- Authorized Dealer · Tech Support · 30-Day Returns
Why it stands out
Best for
Not ideal for
Shop with confidence
Why buy from EMiUZEK
We help you choose, connect and maintain your system—not just ship a box.
- Authentic products
- Compatibility guidance
- Fast tracked shipping
- Firmware and driver support
- Clear warranty process
- Responsive after-sales help
Setup guide
How to connect
What you should know
EMiUZEK buying notes
Frequently asked questions
View full technical specifications
Official product information provided by Fosi Audio
The following product descriptions, specifications and images are provided by the manufacturer.
Description
Fosi Audio IM4 is an open-back wired in-ear monitor built around a 10mm dual-magnet dynamic driver.
Its lightweight CNC-aluminum shells, replaceable nozzles and multiple ear-tip tunings combine a spacious presentation with adjustable comfort and sound.
Why it stands out
Open-back acoustic design
Reduces enclosed-ear pressure and creates a more spacious presentation than a sealed IEM.
10mm dual-magnet driver
An N52 dual-magnet, dual-chamber dynamic driver delivers the full frequency range.
Tunable fit and sound
Two nozzle materials and three ear-tip styles allow practical adjustment.
Lightweight detachable construction
Each aluminum earpiece weighs about 7g and uses a replaceable 0.78mm 2-pin cable.
Best for
- Home and office wired listening
- Listeners who prefer an open, spacious IEM
- Long listening sessions
- Users wanting replaceable cables and tuning accessories
Not ideal for
- Maximum passive noise isolation
- Wireless Bluetooth listening without an adapter
- Very quiet public environments where sound leakage matters
EMiUZEK Buying Notes
- IM4 is open-back, so it isolates less and can leak more sound than a sealed IEM.
- The standard package uses a 3.5mm cable; balanced cables and DS3 bundles depend on the selected variant.
- Choose ear tips for both seal and comfort, then compare nozzles at a safe volume.
Frequently asked questions
Is IM4 open-back?
Yes. It is designed for a more open presentation with reduced isolation.
Does it include Bluetooth?
No. It is a passive wired IEM.
Can the cable be replaced?
Yes, it uses a 0.78mm 2-pin detachable connection.
Is a 4.4mm cable included?
Only with the relevant option or bundle; check the selected variant.
Can it be used with a phone?
Yes, when the phone has a compatible output or USB DAC adapter.
Does the DS3 always come in the box?
No. DS3 is included only in specifically named combo variants.
HOW TO CONNECT
Phone listening
Source icon: phone
Source: Phone / tablet
Connection: 3.5mm output or compatible USB DAC
Output connection: 0.78mm 2-pin cable
Target icon: headphones
Output: IM4 earphones
Portable DAC system
Source icon: phone
Source: USB-C phone / player
Connection: USB DAC to 3.5mm or optional 4.4mm cable
Output connection: Detachable cable
Target icon: headphones
Output: IM4 earphones
Desktop listening
Source icon: computer
Source: PC / desktop DAC
Connection: 3.5mm or compatible balanced headphone output
Output connection: Detachable cable
Target icon: headphones
Output: IM4 earphones
Technical Specifications
Acoustic design
| Feature | Specification |
|---|---|
| Driver | 10mm N52 dual-magnet dual-cavity dynamic driver |
| Diaphragm | PU beryllium-coated |
| Design | Open-back in-ear monitor |
| Impedance | 21Ω |
| Sensitivity | 109dB |
| Frequency response | 20Hz–20kHz |
Construction and cable
| Feature | Specification |
|---|---|
| Shell | 6063 CNC aluminum alloy |
| Connector | 0.78mm 2-pin |
| Standard plug | 3.5mm gold-plated |
| Cable | 4-core 392-strand 5N OFC silver-plated copper |
| Weight | 7g ±0.5g per earpiece; 38g ±1g with cable |
Additional Product Content
Comparison: Which Fosi Audio model is right for you?
| Model | IM4 | DS3 + IM4 combo | IM4 accessory option |
|---|---|---|---|
| Product | Open-back wired IEM | IM4 with DS3 portable DAC | Cable or DAC accessory |
| Standard connection | 3.5mm | USB-C source through DS3 | Depends on selected accessory |
| Best use | Direct wired listening | Portable DAC and gaming system | Upgrading cable or phone connection |
| Important note | Standard package only | Only named combo variants include DS3 | Accessory is not a complete IM4 package |
What's in the box, manuals and downloads
Shipping, warranty and returns
Worldwide Tracked Shipping
We provide tracked international shipping with delivery options and estimated delivery times shown during checkout.
Official Warranty Support
All products sold by EMIUZEK are genuine products with manufacturer warranty support.
Our HiFi specialists provide assistance with compatibility, setup, and technical questions.
Easy Returns
Eligible returns are available according to our return policy.
Please contact EMIUZEK before returning any product so we can provide assistance.