SKU: 32567282030

Fosi Audio IM4 10mm Dual-Cavity Dynamic Driver IEMs

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Description

Fosi Audio IM4 10mm Dual-Cavity Dynamic Driver IEMsFeatures: >High Performance Dynamic Driver IEMs. >Dual Magnetic Dual Cavity Dynamic Driver. >High Purity Beryllium Plated PU Suspension Diaphragm. >High Strength Neodymium N52 Dual Magnets. >Dual Chamber Construction. >CNC Machined Aluminum Alloy Cavities. >Open Back Shell Design. >High Efficiency Acoustic Damping. >Two Sets of Swappable Nozzles. >Ergonomic Design for Comfortable Fit. >5N OFC Silver Plated Cable. Technical Information: >Impedance: 21.

Features:-

>High-Performance Dynamic Driver IEMs.

>Dual-Magnetic Dual-Cavity Dynamic Driver.

>High-Purity Beryllium-Plated PU Suspension Diaphragm.

>High-Strength Neodymium N52 Dual Magnets.

>Dual-Chamber Construction.

>CNC-Machined Aluminum Alloy Cavities.

>Open-Back Shell Design.

>High-Efficiency Acoustic Damping.

>Two Sets of Swappable Nozzles.

>Ergonomic Design for Comfortable Fit.

>5N OFC Silver-Plated Cable.

Technical Information:-

>Impedance: 21Ω.

>Frequency Response Range: 20Hz~20kHz.

>Sensitivity: 109dB.

>Connector Type: 2-pin 0.78mm.

>Termination Plug: 3.5mm Gold-Plated Plug.

>Weight: 7g(per earbud).

Fosi Audio, known primarily for its portable as well as desktop HiFi audio gear is here with its very first pair of in-ear monitors, introducing the Fosi Audio IM4. It’s a single dynamic driver IEM designed with a specially-developed beryllium-plated PU suspension diaphragm. The pair features a dual-magnetic, dual-cavity dynamic driver unit with high-power Neodymium N52 magnets that provide high-efficiency and low distortion in the output. Fosi has crafted the pair with high-precision 5-axis CNC machining process using 6063 series aluminum alloy material. The shells have an open-back architecture to further enhance the sound performance with a wide soundstage. With high-efficiency acoustic damping, premium dual-cavity structure, and professional tuning, the Fosi Audio IM4 promises an enchanting sound response, one that captivates its listeners every single time!!

High-Resolution Clarity with Premium Driver:-

Fosi Audio has equipped the IM4 with a high-performance dynamic driver unit. The pair houses a dual-cavity, dual-magnetic dynamic driver unit that adopts high-purity beryllium-plated dome and PU suspension diaphragm coil. It not only produces a rich sound but also provides enchanting performance with ultra-low THD+N characteristics. The driver is placed neatly in a dual-cavity structure specially optimized to achieve a pure high-fidelity sound with the IM4.

High-Strength Dual-magnetic Configuration:-

In order to produce a high-quality sound with the IM4, Fosi Audio has designed the pair with a strong dual-magnetic architecture that utilizes high-power Neodymium N52 magnets. This dual-magnetic structure produces a strong magnetic flux that ensures swift diaphragm movement. All this results in cleaner sound output with ultra-low THD+N distortion performance. It also provides high-efficiency design to the pair, it now has an output impedance of just 21Ω.

Long-Lasting Comfort, Ergonomic Design:-

Fosi Audio IM4 has got a solid build quality, the pair is crafted using high-precision 5-axis CNC machining process. It is made up of high-quality 6063 series aluminum alloy material. The pair is designed in an ergonomic shape to ensure solid comfort, we also have open-back design with grill vents available on the face panel area. With this open-back design, Fosi ensures the IM4 has a massive soundstage profile.

High-Purity Stock Cable, Solid Accessories:-

Fosi bundles the IM4 with a bunch of high-quality accessories. We have two sets of swappable tuning nozzles, one high-purity 5N OFC silver-plated stock cable, and nine-pairs of ear tips featuring three pairs each of Balanced Sound, Bass Sound, and Deep Bass Sound variants.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 32567282030

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4.5 ★★★★★
Based on 9 reviews
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Product Reviews
B
Verified Purchase
Brian
Los Angeles, US
★★★★★ 5
Great portable display for the price.
Size: 15.6" 1080P
This monitor works very well. I bought because I needed an extra monitor for my iPad on my work desk. But I don’t have an outlet at this desk. The iPad powers the monitor just fine, though it drains the battery pretty quickly. I ended up also buying a 20ft USB-C cable and running that to the nearest outlet to power the monitor and my iPad. I also have a little phone holder standing the display up. The quality is pretty good for the price point. Definitely not my highest quality screen. It's perfect for spreadsheets and the colors are very passable anyway.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 21, 2026
A
Verified Purchase
Andrea Elizondo
Cuba, US
★★★★★ 5
Really good.
Size: 15.6" 1080P
Perfect size. Love the cover that comes with it. Easy storage and portability. Perfect to work on the move. The screen itself looks really good for the price. I connected with the type c and turn on and off as my computer does. Amazing and easy to connect. Doesn't flickers.
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Reviewed in the United States on May 2, 2026
D
Verified Purchase
D. Christensen
Lake Worth, US
★★★★★ 4
Overall great value, for the stated purpose of being a portable monitor
Size: 15.6" 1080P
This is a review of two monitors: MNN Portable Monitor 15.6inch FHD 1080P (no model number listed) M156F01 is marked on the box Arzopa Portable Monitor, 15.6'' 1080P model number: “S1 Table” I ordered the Arzopa monitor first, as kind of an impulse buy. I was going to be traveling and wanted to take my mini Ryzen 9 PC with me, but it had no monitor. I found the Arzopa monitor had good reviews and the price was right so I ordered. Then later I discovered it was a MATTE panel. I’m not sure how I missed that earlier, but I would NOT have ordered it if I knew that it was matte. Matte finishes on monitors are supposed to be easier on eyes as the matte surface supposedly reduces glare. But in my experience, there is a problem with this feature. First, any monitor positioned properly should never have a problem with glare. For example, you don’t position a monitor facing a large window or another source of strong light. If your monitor is positioned correctly, glare should not be a possible problem to be solved. Second, the matte finish on most monitors I have seen tends to greatly distort the picture quality. Imagine you are standing outside at noon, but the area you are in is foggy. The view you have of your surroundings (through a light fog) is similar to the picture quality of any matte finish monitor. At least, in my experience. I was sitting in front of my two large (not portable) monitors, thinking about the mistake I made in ordering a matte finish portable monitor. And I realized…I was so used to using dual monitors that I would really want two monitors for travel, also. I read some reviews of the MNN monitor and someone described it as a GLOSSY panel. Perfect. I decided to order the MNN to use as my “primary” travel monitor with the Arzopa to be used as my “second” monitor for a dual monitor setup while traveling. That led to mistake number 2. They are both matte finish. When I realized this, they had both shipped. And they were delivered very quickly , both arriving on the same day. I decided to give these monitors a try, and I’m glad I did. While they are both described officially as “matte”, the picture qualify is closer to what I would expect from a true “glossy” surface computer monitor. And they both have much more than acceptable image quality. So to compare them: FEATURES: Their features are identical other than their physical controls. For adjusting these monitors, there is a difference between them, and I PREFER one over the other, as far as controls go. Arzopa has multi-function push buttons on the left to adjust settings like brightness/contrast. MNN has push-buttons and a teeny tiny joystick on the right to adjust settings like brightness/contrast. I think this is an odd design decision for a -portable- monitor. The Arzopa controls are both more intuitive and (I believe) probably more sturdy / more likely to be reliable over time. We’ll see if the tiny joystick of the MNN survives a few trips bouncing around in my checked bags. DISPLAY QUALITY I was very pleasantly surprised by the image quality of both of these monitors. I would rate them both a solid 9/10 on image quality. I’ve seen better, but only with OLED panels. Between the two if I had to pick a winner for image quality it would be the MNN. But the difference is so slight. I think they both deserve a “9”. While I can tell they are both matte (and I do not like that) the matte finish of these monitors is not as “foggy” as most matte monitors. It’s not matte enough to detract from the overall image quality, which is great. The factory settings of both monitors had the brightness (black lefel) set too high. Brightness is what controls how “black” black items will appear. If the Brightness is set too high, then something which should be color black will appear to be gray or (worse) even light gray. After I turned down the brightness a bit on both monitors, the black level of both was very satisfying. Speakers: I would never try to use speakers on a portable monitor, so I can’t comment on this. I don’t think the Arzopa even has speakers, but it doesn’t matter, as I would not use those. STAND: They have virtually identical magnetically attached pleather stands that can be used to support the monitors in vertical or horizontal orientation. The magnets on both are pretty weak. However, it should be adequate for use on a solid desk or table. You might not be happy on an airplane if you hit turbulence at all. Summary and suggestion for improvement: I would give both of these a 4-star rating on the Amazon scale. To earn a 5-star rating I would suggest: 1) Replace the magnetic stand with something that attaches to the monitor more firmly. 2) Include a USB-C cable with a right-angle connector on one end. For dual monitor use, these both have cables sticking out the left side. If you want to set them side by side, you need to keep them about 2” apart, because the cables interfere with setting them close together, like you want to. The most obvious solution would be a right-angle USB-C cable. I have ordered one. But it would cost nothing for Arzopa and MNN to include this. 3) Make the above changes without increasing the price. If you could do that, I would rate these monitors a solid 5/5. There are better monitors for sale. But for the stated purpose and price? These are close to what I would want. Very close. FINAL THOUGHT: (Which One Should I Buy?) There are many portable monitors available with plenty of options in the same relative price range. The two I am reviewing here are a couple of the most highly rated. If you are trying to choose between these two specific monitors, I would recommend you buy the Arzopa. While the MNN has slightly better image quality, they both have really good image quality. I think the design of the Arzopa is just a bit more appropriate for the stated purpose of being portable. If you are leaning toward the MNN however, I would not discourage you from buying it. If you’ve narrowed down your decision to these two specific monitors, I don’t think you can possibly choose “wrong” if you buy only one of them. They both exceeded my expectations.
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Reviewed in the United States on February 16, 2025
H
Verified Purchase
Humberto
Pawtucket, US
★★★★★ 5
Great product
Color: Black, Size: Case for iPad (A16) 11th/10th Generation 11/10.9''
Easy to install, Really fit well, durable and look good and the customer service was really nice when I need something
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 25, 2026
N
Verified Purchase
Nikolette Scruggs
Massapequa, US
★★★★★ 5
Great case - does its job!
Color: Black, Size: Case for iPad (A16) 11th/10th Generation 11/10.9''
This is a great case for a kid (or adult) who is rough on their iPad. My kids iPad has been dropped, thrown, etc. and the case has done its job. We like having the built in screen protector which is fairly easy to clean. The case has a strap and a kickstand if needed and looks professional if that’s important to you. Worth the money!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 29, 2026

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