AIAIAI UNIT-4 MKII – Wireless Studio Monitors, Fully Portable

The AIAIAI UNIT-4 MKII is a pair of battery-powered 2-way monitors that stream uncompressed audio over W+ Link, charge over USB-C and pack into their own hard case.

Key Features

• Uncompressed W+ Link wireless: 44.1 kHz 16-bit audio at a fixed 16 ms, up to 12 m.
• X04 transmitter with its own battery: plugs into grooveboxes, mixers and DJ gear with no USB host.
• USB-C power: both speakers and the transmitter charge from standard USB-C supplies.
• 20-hour battery: a 77 Wh cell per speaker, recharged in about 2 hours.
• Bi-amped 2-way design: 4 inch paper cone woofer and 1 inch silk dome tweeter, 2 x 30 W.
• Built to be repaired: glue-free chassis with replaceable batteries and driver units.

Customer Benefits

You get the same flat 50 Hz to 20 kHz reference you would expect from a wired desktop pair, without the cables that usually tie it to one room. Feed the X04 from a laptop, an MPC, a Digitakt or a mixer, set the speakers where the room sounds best, and keep working for a full day on battery. When it is time to move, both speakers, the transmitter and the leads go into one case, and one charger type brings everything back to full.

Quick Specs

• Drivers: 4 inch paper cone woofer, 1 inch silk dome tweeter
• Amplification: 2 x 30 W continuous, 2 x 80 W peak per speaker
• Frequency response: 50 Hz – 20 kHz (±2 dB); 40 Hz – 40 kHz (-10 dB)
• Peak SPL: 105 dB
• Wireless: W+ Link (16 ms, uncompressed 44.1 kHz 16-bit, 12 m), Bluetooth 5.2
• Inputs: 3.5 mm mini-jack, 6.3 mm TRS balanced
• Battery and power: 77 Wh, 20 h playback, 2 h charge, USB-C
• Size and weight: 156 x 258 x 114 mm, 2.54 kg per speaker

In the Box

• 2 x UNIT-4 MKII speakers
• 2 x UNIT-4 USB-C power supplies
• 1 x X04 W+ Link transmitter
• 1 x UNIT-4 carrying case

Use Cases / Ideal For

• Mobile producers working from a laptop or groovebox
• DJs practising away from the booth
• Small rooms and shared spaces where cables are a problem

Compatibility

Connect over W+ Link via the X04 transmitter, over Bluetooth 5.2, or wired through 3.5 mm or balanced 6.3 mm TRS, with 3/8 inch threads for standard mic stands.

Pros & Cons

✅ Pros:

• Uncompressed low-latency wireless that Bluetooth monitors cannot match
• Battery-powered X04 transmitter works with standalone hardware
• USB-C charging and an included hard case make it genuinely portable
• Repairable design with replaceable batteries and drivers

⚠️ Cons:

• 4 inch woofers limit low-end weight and level in larger rooms
• App EQ only, no room correction

The UNIT-4 MKII is the version of AIAIAI's wireless monitor that finally travels as lightly as it sounds: reference tuning, uncompressed wireless and a full day on battery in one case.