Acton IV

Acton IV is a stereo Bluetooth speaker in a bass-reflex cabinet. It uses one 4 inch woofer and two 0.75 inch tweeters with waveguides, driven by three Class D amplifiers (60 W for the woofer, 25 W each for the tweeters). The tweeters and waveguides are designed to spread sound over a wider area, and a redesigned bass port is intended to give tighter bass at higher volumes and make placement near walls easier.

The top panel carries bass, treble and volume knobs, a power switch, a media jog control, a source button and a customisable M-button. The M-button can open a playlist (via Spotify Tap) or change sound settings. The Marshall app provides EQ settings and placement compensation (room calibration).

Wireless connection is Bluetooth 5.3 with multipoint and the SBC, AAC, LDAC and LC3 codecs. Built-in Auracast lets the speaker act as a receiver, so it can join a broadcast from a Marshall hub such as Heddon, or from phones and other Auracast devices. For wired sources there is a 3.5 mm AUX input and an RCA input; a turntable needs a preamp. The cabinet is made of FSC-certified MDF, and parts such as the front cover and knobs are user-replaceable.