FiiO Retro Box

RETRO BOX Desktop Bluetooth Speaker

• Compatible with FIIO JM21/M21/M33 players
• Bluetooth/USB DAC modes
• High-resolution LDAC Bluetooth
• 2+2 acoustic design
• 5 W + 5 W full-range power
• 10.5 hours of extremely long battery life
• Hi-Fi/Retro sound presets
• Built-in microphone

The perfect companion for FIIO players – Enhance your sound

This speaker is specifically tailored to the FIIO JM21, M21, and M33 series. Once connected via Bluetooth, your player instantly transforms into a retro-style speaker reminiscent of a cassette recorder. It’s not only an excellent companion for music players but also an upgrade to your daily listening experience.

Dual-Core Acoustic Design – Every Seat Is the Best Seat

With two dedicated speakers and two passive radiators housed in separate chambers, your sound remains clear and free of crosstalk. Thanks to this design, the speaker fills every corner of your room with rich and immersive sound—making every spot a “sweet spot.”

*The speakers are offset to the side to make room for the player. This side-firing design creates a more even and balanced sound field that distributes the music more effectively throughout the room.

Tireless performance, lasting impression

Two 18500 batteries are connected in parallel to minimize internal resistance and supply the two-channel amplifier with ample power. The result is a robust continuous output of 5 W + 5 W, allowing the two 40-mm drivers to reach their full potential—experience a rich and powerful sound with impressive dynamic range.

Dual-Mode Connectivity, Hi-Fi Anywhere

Bluetooth Mode: Features Bluetooth 6.0 and LDAC support. Experience refined, near-lossless sound quality even over a wireless connection.

USB DAC mode*: Connect the speaker directly to your desktop or laptop PC to transform it into a high-end audio station—complete with high-quality speakers that deliver an immersive, wired listening experience.

*The USB port is used for both data transfer and power supply. The speaker automatically charges or draws power as soon as it is connected. FiiO recommends avoiding connection to smartphones or tablets to prevent rapid battery drain.

*UAC 1.0 support is available without drivers for sampling rates of 44.1 kHz, 48 kHz, and 96 kHz.

Tailor your sound preferences—for every playlist

A built-in high-performance DSP chip lets you choose from HiFi, Retro, Pop, and Warm presets to suit any genre.

Simply press the volume control down to switch between profiles and find the sound that perfectly matches your taste.

Thoughtful design that fits your life

Intuitive controls

Turn the 360° dial for smooth volume control or press it to switch between EQ modes. The tactile buttons are clearly arranged so you can control your music by touch alone.

Seamless phone calls

With the built-in silicone microphone on top, you can easily pause tracks, answer calls, or activate your voice assistant.

Portable design

Thanks to the built-in mounting loops, you can attach a carrying strap for convenient transport—making it a great music companion wherever you go.

*Shoulder strap and screws sold separately.

Built for Stability

A reinforced housing and vibration-damping feet ensure the speaker remains absolutely stable even when playing highly dynamic music. FiiO’s “PUSH” pop-out design makes swapping out or removing your player a breeze.

Smarter app control, continuous development

With the FIIO Control app, you can personalize your sound with custom EQ settings and switch Bluetooth codecs in an instant, while seamless firmware updates ensure your device always performs at its best. Keep an eye out for regular app updates to access new features.

Package Contents

RETRO-BOX*1

USB data cable*1

M21 and JM21 mounting insert*1

Quick Start Guide*1

Warranty card*1

User manual*1

Technical Specifications

Dimensions: approx. 152.8 x 98.8 x 76 mm (excluding feet and controls)

Weight: approx. 683 g

Color: White/Black

Operating modes: Bluetooth reception mode/USB DAC mode

Bluetooth reception: V6.0, supports SBC/LDAC

Power supply: DC 5 V ≥ 2 A

Charging time: approx. 2.5 h

Battery life: approx. 10.5 h (Data from FIIO Labs in SBC format. Actual performance may vary depending on the music source and usage conditions)

Speaker parameters: 2 × 40 mm 4 Ω full-range speaker drivers

Frequency response: 65 Hz–20 kHz

Output power: 5.3 W × 2

Supported sampling rates for USB DAC: 44.1 kHz/48 kHz/96 kHz, 16/24/32-bit