- Fosi Audio IM4 Earphones
- 3.5 mm Cable
- Carrying Pouch
- User Manual
- Quick Guide
- Set of Brass Nozzles
- Set of Balanced Ear Tips
- Set of Bass Ear Tips
- Set of Deep Bass Ear Tips
Fosi Audio IM4 Open-Back In-Ear Monitors (Black)
- Open-back housing helps reduce pressure buildup for a more natural sound
- 10 mm N52 dual-magnet dynamic driver delivers detailed wired audio
- PU beryllium-coated diaphragm supports clear vocals and balanced output
- Brass and aluminum nozzles let listeners adjust bass, mids, and treble
- 3 ear tip styles support bass, deep bass, and balanced listening
- Each earbud weighs 7 g plus or minus 0.5 g for long sessions
- 2-pin 0.78 mm detachable cable connects to a 3.5 mm plug
The Fosi Audio IM4 Open-Back In-Ear Monitors bring wired portable listening to users who want spacious sound, secure comfort, and flexible tuning in a compact IEM. Its open-back acoustic structure helps reduce internal reflections and pressure buildup, supporting a more natural presentation for music, gaming, and focused listening at home or on the go.
Open-Back Wired Sound
The IM4 uses a 10 mm N52 dual magnet dual cavity dynamic driver with a PU beryllium-coated diaphragm. This driver system is built for clear detail, balanced output, and controlled dynamics without stacking multiple drivers. The open-back design and acoustic damping wool work together to reduce harsh resonance and create a wider listening feel than a conventional closed in-ear design.
Tunable Fit and Response
Listeners can fine-tune the sound with the included brass and aluminum nozzles. The aluminum nozzle supports added bass and reduced sibilance, while the brass nozzle supports clearer mids and treble. Three ear tip styles also let users choose a bass, deep bass, or balanced fit, making the IM4 adaptable for different music preferences and ear shapes.
Lightweight Aluminum Build
Each earbud weighs 7 g plus or minus 0.5 g and uses a 6063 CNC aluminum alloy shell with a smooth metal finish. The detachable 2-pin 0.78 mm cable connects to a 3.5 mm gold-plated plug, giving listeners a simple wired setup for compatible phones, DACs, players, computers, and audio gear.
General
Product:
| Brand | Fosi Audio |
| Model | IM4 |
| Product Type | Open-Back In-Ear Monitors |
| Color | Black |
Acoustic Design:
| Driver Unit | 10 mm N52 Dual Magnet Dual Cavity Dynamic Driver |
| Diaphragm | PU Beryllium Coated Diaphragm |
| Sensitivity | 109 dB |
| Impedance | 21 ohms |
| Frequency Response | 20 Hz to 20 kHz |
Build:
| Shell Material | 6063 CNC Aluminum Alloy |
| Weight Per Earbud | 7 g plus or minus 0.5 g |
| Weight Including Cable | 38 g plus or minus 1 g |
| Dimensions | Needs Review |
Cable and Connection:
| Cable | 4 Core 392 Strand 5N OFC silver-plated copper cable |
| Connector | 2 Pin 0.78 mm |
| Audio Jack | 3.5 mm Gold-Plated Plug |
Starting at $16.66/mo
Estimated over 6 months with Affirm, subject to eligibility and approval.
Flexible payment options available
Interest-free installments and monthly financing may be available through Shop Pay on eligible purchases.
Starting at $25.00
No interest if paid in full by the promotional terms. Minimum monthly payments required and subject to credit approval.
Free Standard Shipping
Orders of $25 or more qualify for free standard shipping on eligible items.
Most in-stock orders placed before 1 PM EST Monday–Thursday ship the same business day. View Shipping Policy
Free Local Pickup
Please call for store stock availability. Requests made before 2:30 PM EST can be available for next-day pickup. Learn more
Frequently Asked Questions
How do I return an item?
How do I return an item?
Returns are incredibly simple. Please log into your account, find your item you wish to return and follow the prompts to make a return. If you do not have an account, click here to find your order and make a return.
Will I receive a full refund when I return an item?
Will I receive a full refund when I return an item?
You will receive a full refund when you return an item in its original manufacturer’s packaging, undamaged and unmarked. If the item you are returning is priced at less than $35, you will be charged a 15% restocking fee. Please note you will not be refunded any shipping charges.
How many days do I have to make a return?
How many days do I have to make a return?
You have 30 days to make a return. During the holiday season, from November 1 to December 31, we extend the return window to 60 days.
My item was damaged in transit. How do I place a return?
My item was damaged in transit. How do I place a return?
If your order has been noticeably damaged in transit, we strongly recommend that you refuse delivery and notify us immediately. Claims for missing items or items damaged in transit must be made within 48 hours of delivery. If there is carrier damage, please contact support@focuscamera.com with your order number and a description of the damage.
There’s an issue with my order, what should I do?
There’s an issue with my order, what should I do?
Oh no! Please contact our customer service team so we can resolve the issue immediately. You can call us on 1.800.221.0828, email us at support@focuscamera.com, or send us a message here.
Can I exchange an item?
Can I exchange an item?
We do not currently offer exchanges. Please return the item you purchased within 30 days and order what you’d like instead.
If I ordered a kit, do I have to return all the items?
If I ordered a kit, do I have to return all the items?
If you ordered a kit, you must return all components and accessories to receive a full refund.
I ordered a product that included a free item. I’d like to return it, do I need to return the free item as well?
I ordered a product that included a free item. I’d like to return it, do I need to return the free item as well?
If you ordered a product that included a free item, you must include the free item with your return. If not, your return will not be accepted and you will not receive a full refund.
Do you offer repairs?
Do you offer repairs?
We currently only offer camera repairs at our Brooklyn store. The item must be dropped off and collected in person as we do not accept shipped items for repair. For more information, please call our Brooklyn store on 1.718.431.7900.
What is your return policy?
What is your return policy?
Most items can be returned within 30 days for a full refund. Click here to read our full return policy.
