Monitor Audio

Monitor Audio Radius 3 4G Bookshelf Speakers

  • pair of black monitor audio radius 3 speakers
  • pair of white monitor audio radius 3 speakers
  • back of white monitor audio radius 3 speaker
  • back of black monitor audio radius 3 speaker

RADIUS 3 4G BLACK

$999.00
$999.00

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Ships mid-August 2026.

Color: Black

For store pickups, please call for availability.

Product Overview

The Monitor Audio Radius 3 4G is a 2-way ported mini-monitor and the flagship bookshelf model in the Radius Series 4G lineup, designed to deliver genuine hi-fi performance across stereo listening, TV and film audio, gaming, near-field desktop use, and multi-room installations. Its 4.5-inch C-CAM RST III bass-mid driver reaches 44 Hz in-room, exceptional for a speaker measuring 255 x 150 x 201 mm, achieved through a HiVe II reflex port enlarged 50% compared to the Radius 90 3G predecessor. A redesigned 25mm C-CAM Gold Dome tweeter with an external magnet motor system brings a new level of high-frequency precision, and Through-Bolt Driver Bracing and a new crossover contribute structural and acoustic rigour throughout. StereoNET awarded the Radius 3 4G its Applause Award, describing it as "clearly the best of Monitor Audio's long line of small speakers so far."

Features

  • 2-way ported (bass reflex) compact mini-monitor
  • C-CAM RST III bass-mid driver
  • C-CAM Gold Dome tweeter with redesigned external magnet motor system
  • RST III (Rigid Surface Technology III) cone geometry, reduces resonance and breakup across the frequency range
  • Through-Bolt Driver Bracing, drive units locked to cabinet rear at specified torque
  • HiVe II reflex port, 50% larger cross-section than Radius 90 3G predecessor, tuned to 53 Hz
  • New crossover design with precision component selection
  • Compatible bracket: FIX-M (wall, adjustable angle)
  • Optional accessories: Radius Floor Stand 4G, Radius Desk Pad 4G

Specifications

System format — 2-Way

Drive units — 1x 4.5" RST III bass-mid driver / 1x 25mm C-CAM Gold Dome tweeter

Frequency response — 44 Hz to 35 kHz (in-room, -6dB)

Sensitivity — 84 dB (2.83 Vrms @ 1m, free-field)

Nominal impedance — 8 Ohms

Minimum impedance — 4 Ohms @ 250 Hz

Bass alignment — Ported

Port tuning frequency — 53 Hz

Crossover frequency — 2.7 kHz

Recommended amplifier power — 40 to 75 W into 8 Ohms / 75 to 150 W into 4 Ohms

Continuous power handling — 75 W

Maximum peak SPL — 107 dB

Dimensions (H x W x D) — 255 x 150 x 201 mm (10 1/16 x 5 7/8 x 7 15/16 in)

Weight — 3.7 kg (8 lb 3 oz) each

Finishes — High Gloss Black, Satin White

Compatible MAG brackets — FIX-M

Sold as — Pair

Warranty — 5 years

The HiVe II Difference: Engineering More Bass From a Compact Cabinet

The most consequential internal change in the Monitor Audio Radius 3 4G is the enlarged HiVe II reflex port. At 50% larger cross-section, it allows more air to move at lower velocities, reducing turbulence at higher output levels while extending bass output deeper. Tuned to 53 Hz, the port combines with the 4.5-inch RST III driver to produce in-room bass extension to 44 Hz, territory that previously required a larger cabinet or a separate subwoofer in the Radius range.

radius 3 4g speakers on a desktop

From Desktop to Living Room: A Speaker Built for Multiple Roles

On the Radius Desk Pad 4G the Radius 3 4G becomes a precise near-field monitor for desktop listening or gaming. On the Radius Floor Stand 4G it becomes the centrepiece of a compact living room stereo. Wall-mounted via the FIX-M bracket it serves as a reference point for TV audio or a home cinema satellite. Its 84 dB sensitivity, 107 dB peak SPL, and 44 Hz bass extension give it the dynamic range to perform credibly in each of these roles.

Award-Winning Performance in a Compact Form

The Monitor Audio Radius 3 4G earned StereoNET's Applause Award for products that exceed expectations for their category. The reviewing team described it as producing "a fast, driving beat allied to an impressively expansive soundstage," treble with "the finesse of a speaker twice the price," and "almost supernatural stereo imaging" with a soundstage that is "magically hanging in space."

Unboxing Radius Series 4G

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Frequently Asked Questions

What is the Monitor Audio Radius 3 4G and who is it designed for?

The Monitor Audio Radius 3 4G is a 2-way ported mini-monitor and the flagship bookshelf model in the Radius Series 4G range, designed for stereo listening, TV audio, gaming, desktop use, and multi-room installations where genuine high fidelity is required in a compact footprint. StereoNET awarded it the Applause Award, describing it as "clearly the best of Monitor Audio's long line of small speakers so far." The Monitor Audio Radius 3 4G is available at Trutone Electronics in Mississauga, Ontario.

How far does the Monitor Audio Radius 3 4G extend in the bass?

The Monitor Audio Radius 3 4G reaches 44 Hz in-room at -6dB, exceptional for a speaker measuring 255 x 150 x 201 mm. This comes from a 4.5-inch C-CAM RST III bass-mid driver in a HiVe II ported enclosure tuned to 53 Hz, with the port 50% larger than the outgoing Radius 90 3G. In smaller rooms it can deliver meaningful bass without a subwoofer; adding a Monitor Audio subwoofer extends performance to full-range output.

What changed in the Monitor Audio Radius 3 4G compared to the Radius 90 3G?

The Monitor Audio Radius 3 4G is a comprehensive redesign of its predecessor, introducing a new C-CAM Gold Dome tweeter with an external magnet motor system, RST III cone geometry, Through-Bolt Driver Bracing, a redesigned crossover, and a HiVe II port 50% larger than the one in the Radius 90 3G. Monitor Audio describes the 4G generation as a "comprehensive reinvention" rather than an incremental update.

What amplifier power does the Monitor Audio Radius 3 4G need?

The Monitor Audio Radius 3 4G is rated for 40 to 75 watts per channel into 8 ohms, or 75 to 150 watts into 4 ohms. At 84 dB sensitivity with an 8-ohm nominal impedance, it is compatible with a broad range of integrated amplifiers and AV receivers.

What did StereoNET say about the Monitor Audio Radius 3 4G?

StereoNET awarded the Monitor Audio Radius 3 4G its Applause Award for outstanding products in their category. The reviewer described "a fast, driving beat allied to an impressively expansive soundstage," treble with "the finesse of a speaker twice the price," and "almost supernatural stereo imaging" with a soundstage "magically hanging in space."

What mounting and placement options does the Monitor Audio Radius 3 4G support?

The Monitor Audio Radius 3 4G supports desktop placement on the Radius Desk Pad 4G, freestanding use on the Radius Floor Stand 4G, and wall mounting with the FIX-M bracket at 0, 15, or 30-degree angle adjustment across 14 positions. Unlike the Radius 1 4G, it is not compatible with the MASM ceiling ball-joint bracket. The FIX-M bracket is available in Black or White.

Is the Monitor Audio Radius 3 4G good for TV, gaming, and home cinema?

The Monitor Audio Radius 3 4G is well suited for TV and home cinema, covering front left and right, satellite, and surround channel duties in multichannel systems. Its 84 dB sensitivity, 107 dB peak SPL, and 44 Hz bass extension give it considerably more output and dynamic range than the Radius 1 4G for screen-based entertainment. Pairing it with a Monitor Audio subwoofer completes the system for full-range film and music performance.

Can the Monitor Audio Radius 3 4G go on a shelf close to a wall?

The Monitor Audio Radius 3 4G has a rear-mounted HiVe II reflex port, meaning placement flush against a back wall restricts port airflow and can cause bass muddiness. Some stand-off clearance behind the speaker is recommended when shelf-mounted. The FIX-M wall bracket provides a consistent stand-off distance, and the Radius Desk Pad naturally positions the cabinet with rear clearance on a desk.

What driver technology is used in the Monitor Audio Radius 3 4G?

The Monitor Audio Radius 3 4G uses a 4.5-inch C-CAM RST III bass-mid driver paired with a 25mm C-CAM Gold Dome tweeter, both with independently optimised motor systems. The Gold Dome tweeter uses a new external magnet motor design introduced for the 4G generation, replacing the internal puck magnet of previous Radius models. Through-Bolt Driver Bracing locks both units to the cabinet rear at a specific torque setting to reduce chassis resonance.