Fosi Audio SW10 Active Subwoofer vs Fosi Audio IM4 Open-Back In-Ear Monitor: Which One Should You Buy?

Fosi Audio has built a strong reputation among audio enthusiasts for delivering high-performance sound equipment at accessible price points. From home audio systems to personal listening gear, the brand focuses on innovative engineering, premium materials, and user-centric design. Two standout products from very different categories are the Fosi Audio SW10 Active Subwoofer and the Fosi Audio IM4 Open-Back In-Ear Monitor.

While both are designed to elevate your audio experience, they cater to completely different listening environments and user needs. One transforms your room with powerful, cinematic bass, while the other delivers intimate, high-resolution sound directly to your ears. This guide breaks down both products in depth to help you decide which one is the right purchase for you.

Overview of the Two Products

Before diving deep, here’s a quick overview:

Fosi Audio SW10 Active Subwoofer: A 10-inch powered subwoofer designed for home theaters, music systems, and gaming setups.

Fosi Audio IM4 Open-Back In-Ear Monitor: A lightweight, audiophile-grade IEM designed for personal listening with a wide soundstage and balanced tuning.

Now let’s explore each product in detail.

Fosi Audio SW10 Active Subwoofer – Deep, Room-Filling Bass

The Fosi Audio SW10 Active Subwoofer is designed to deliver immersive low-frequency performance for home audio setups. Featuring a 10-inch down-firing driver, the SW10 uses floor reflections to create smoother, more natural bass while protecting the driver from direct exposure. This design choice results in bass that feels deep and enveloping rather than aggressive or boomy.

Powered by a 200W Class D amplifier with up to 500W peak power, the SW10 produces a powerful low-end response suitable for movies, music, and gaming. Explosions feel impactful, soundtracks gain weight, and bass-heavy music achieves a physical presence that standard speakers simply cannot provide.

Key Sound Technologies

Exclusive Precision DSP Algorithm: Tuned by the Fosi Acoustic Team to maximize performance while protecting the driver.

DRC Limiting Technology: Prevents distortion and overload during high-dynamic scenes.

Dual EQ Modes:

EQ1: Rich, immersive bass for movies and entertainment.

EQ2: Faster transients and tighter bass for music and Hi-Fi listening.

Design and Build Quality

The SW10 weighs 14kg, giving it excellent stability and reduced vibration. Rear dual bass ports improve airflow, allowing deeper and fuller low-frequency output. Its compact, minimalist cabinet (14.17 x 14.17 x 15.75 inches) blends well with modern interiors without drawing unnecessary attention.

Connectivity and Control

Supports LFE and RCA inputs

RCA output allows daisy-chaining another subwoofer or amplifier

Adjustable phase (0°–180°) and crossover (40Hz–180Hz) for seamless integration with main speakers

Automatic signal detection for energy-efficient power management

Best For: Home theater enthusiasts, gamers, and music lovers who want room-shaking bass and cinematic immersion.

Fosi Audio IM4 Open-Back In-Ear Monitor – Audiophile Precision on the Go

The Fosi Audio IM4 Open-Back In-Ear Monitor is crafted for listeners who prioritize clarity, balance, and long-term comfort. Unlike traditional closed IEMs, the IM4’s open-back design allows air and sound to flow more naturally, creating a wider soundstage and reducing listening fatigue.

At its core is a 10mm beryllium-coated dynamic driver paired with an N52 dual-magnet, dual-cavity structure. This configuration provides excellent control over bass while maintaining clean mids and detailed highs. The result is a Hi-Fi sound signature that feels spacious and natural rather than compressed.

Sound Signature Highlights

• Balanced bass that is present but not overpowering
  
  
• Clear, realistic midrange for vocals and instruments
  
  
• Smooth, non-fatiguing treble
  
  
• A wide soundstage is uncommon in traditional IEMs
  
  
• Comfort and Build

Each earbud weighs just 7 grams, making the IM4 suitable for extended listening sessions. The shells are CNC-machined from 6063 aluminum alloy, offering durability, hypoallergenic comfort, and a premium feel. The distinctive orange metal grille adds visual character without compromising acoustics.

Customization and Accessories

Includes three types of ear tips: Bass, Deep Bass, and Balanced

Two interchangeable sound nozzles (Brass and Aluminum) to fine-tune sound

Detachable 2-pin 0.78mm cable with both 3.5mm and 4.4mm compatibility

Technical Specifications

• Sensitivity: 109dB
  
  
• Impedance: 21Ω
  
  
• Frequency Response: 20Hz–20kHz
  
  
• High-purity silver-plated OFC cable

Best For: Audiophiles, commuters, and music lovers who want detailed, fatigue-free sound in a portable format.

Add video here

Fosi Audio SW10 vs IM4: Feature Comparison Chart

Which One Should You Buy from Fosi Audio?

The choice between the Fosi Audio SW10 and IM4 depends entirely on how and where you listen to audio.

Choose the SW10 Active Subwoofer if:

You want cinematic bass for movies and gaming

You listen to music through speakers at home

You want to enhance an existing audio system

Choose the IM4 Open-Back IEM if:

You value clarity, balance, and soundstage

You listen on the go or at your desk

You prefer personal, immersive listening without disturbing others

In short, the SW10 fills your room with sound, while the IM4 places you inside the music. Both represent Fosi Audio’s commitment to high-quality sound, just tailored to very different listening lifestyles.

The Choice Is Yours

Choosing between the Fosi Audio SW10 Active Subwoofer and the Fosi Audio IM4 Open-Back In-Ear Monitor ultimately comes down to how you experience sound in your daily life. If you crave deep, cinematic bass that transforms movies, games, and music into a powerful, room-filling experience, the SW10 is a clear upgrade that will instantly elevate your home audio setup. It adds depth, realism, and physical impact that standard speakers simply cannot deliver.

On the other hand, if your priority is precision, comfort, and immersive personal listening, the IM4 offers remarkable value for audiophiles who want detail and balance without fatigue. Its open-back design and customizable sound make it a reliable companion for long listening sessions at home or on the move.

Whichever you choose, investing in Fosi Audio means choosing thoughtful engineering, solid build quality, and sound performance that exceeds expectations at its price point. Explore Fosi Audio’s lineup today and take the next step toward a more refined and enjoyable listening experience.