AIAIAI UNIT-4 MK2 is a portable, battery-powered 2-way studio monitor that runs about 20 hours on a charge. It takes audio over Bluetooth, over AIAIAI's W+ Link wireless connection or from a cable. You get one black speaker, its USB-C power supply and a protective pouch.

What Changed in MK2

The original UNIT-4 charged from a DC power adapter. MK2 charges over USB-C, so it powers up with the same kind of cable as a laptop or phone. AIAIAI kept the sound, the buttons and the 20-hour battery the same as the original model.

Sound

UNIT-4 is tuned flat out of the box for music creation and critical listening, with clear, detailed sound and rich bass. With the bass vent and a bass-boosting EQ, clean bass reaches down to 40 Hz. In the AIAIAI app you can choose a predefined sound profile or adjust the 5-band EQ.

Connections

• Bluetooth 5.2: plays music from any Bluetooth device. Pair a second UNIT-4 for stereo Bluetooth playback.
• W+ Link: uncompressed wireless audio with 16 ms latency from an X04 or X02 transmitter (sold separately). USB-C audio sources connect through the transmitter.
• Cable: 3.5 mm mini-jack and 6.3 mm balanced TRS inputs for a mixer, an audio interface, synths, DJ gear or another audio source.
• Stereo or mono: the Stereo/Mono button sets the speaker to Left, Right or Mono.

Portable

The speaker is 3 litres in volume and weighs 2.5 kg, and the rear bass vent doubles as a carry handle. A removable steel grille protects the woofer and tweeter. The drawstring pouch in the box, made from compostable fabric, is for longer trips. A 3/8-inch thread fits a standard microphone stand.

Designed to Last

UNIT-4 is built without glue and comes apart with two screwdrivers, so the battery, the drive units and other key parts can be replaced. Its main parts are made from 100% post-consumer recycled plastic.

Specifications

• Model: UNIT-4 MK2 (MKII)
• Design: 2-way active monitor, bass reflex
• Woofer: 4-inch high-excursion paper cone
• Tweeter: 1-inch silk dome
• Crossover: 3 kHz
• Amplifier: 2 x 30 W continuous, 2 x 80 W peak
• Frequency response: 50 Hz to 20 kHz (±2 dB)
• Frequency range: 40 Hz to 40 kHz (-10 dB)
• THD: under 1% nominal, under 10% at peak output
• Self-generated noise: under 20 dB
• DSP: loudness-adaptive bass boost, 5-band EQ in the AIAIAI app
• Bluetooth: 5.2, SBC and AAC
• W+ Link: uncompressed 44.1 kHz, 16-bit, 16 ms latency, about 12 m range, with X04 or X02
• Analog inputs: 3.5 mm stereo mini-jack, 6.3 mm balanced TRS (mono)
• Power: USB-C
• Battery: 77 Wh, about 20 hours playback, 2 hours to charge
• Mounting: 3/8-inch thread for a microphone stand
• Dimensions: 156 x 258 x 114 mm (6.14 x 10.16 x 4.49 in), W x H x D
• Weight: 2.54 kg (5.6 lb)
• Colour: Black

In the Box

• UNIT-4 MK2 (1 pc)
• UNIT-4 Power Supply USB-C
• Protective Pouch