Subwoofers — Monitor Audio Radius 390

The Radius 390 is a powered subwoofer from Monitor Audio's Radius range, built in a compact form factor for placement flexibility. Monitor Audio's Radius range is specifically designed around unconventional, space-saving cabinet shapes, and this subwoofer extends that design philosophy into the bass-reinforcement category.

Position in line

It sits above the Radius 380 in Monitor Audio's Radius subwoofer hierarchy, near the Vestra W10 in general positioning. As the larger of two closely related Radius subwoofers, this model likely offers modestly more output or bass extension than the Radius 380 while sharing the range's compact design philosophy.

Key specs that matter

Rated response is 40 Hz to 120 Hz. The built-in amplifier is rated at 200 W. At 34.8 x 33.0 x 34.5 cm and 13.76 kg it is a compact, roughly cube-shaped cabinet, practical for placement flexibility in a variety of room configurations.

Sound and use context

Expect useful bass reinforcement for a small to medium room, with the compact cabinet favouring placement flexibility over the deepest possible extension - a sensible choice for a room where a large, conventional subwoofer would prove visually or physically excessive.

Pairing

Standard line-level or speaker-level subwoofer inputs work with any stereo or AV receiver offering a subwoofer output, so integration should present no particular challenge.

Alternatives

The Radius 380 sits below this model in Monitor Audio's range. The Vestra W10 offers a similarly compact alternative with a wider rated bandwidth, worth comparing directly on specific frequency response before choosing between these closely positioned compact subwoofers. Monitor Audio broader Radius and Vestra ranges give buyers a reasonably wide set of compact subwoofer options to choose from, and a dealer conversation about the specific main speakers already owned helps clarify which model within that broader range makes the most sense. Corner or wall placement remains the simplest way to reinforce output from a compact subwoofer like this one. Overall this remains a sensible, space-conscious choice for a small to medium room needing modest reinforcement. A phase switch, where fitted, is worth experimenting with to find the smoothest blend with the main speakers. Cable length between amplifier and subwoofer should stay reasonably short for the cleanest signal. A dedicated subwoofer cable run helps avoid any hum introduced by a shared or undersized cable.