Stereo portable speaker Ultimate Ears BOOM 4 — Blue, driver 4 cm, passive radiator 46.1×65.2 mm, Bluetooth range 45 m

Ultimate Ears BOOM 4 is a stereo portable speaker in a cylindrical blue housing designed for versatile indoor and outdoor use. It integrates a 4 cm driver and a passive radiator (46.1 × 65.2 mm) to deliver balanced sound with a stated maximum sound pressure level of 85 dB. The speaker supports Bluetooth wireless audio with A2DP profile and offers up to 45 m range for flexible placement. With a lightweight build of 0.62 kg and a one-touch control for basic playback commands, BOOM 4 is intended for on-the-go listening and shared audio situations.

Advantages

The design provides spatial 360° stereo sound from its cylindrical enclosure, promoting even sound dispersion around the unit. A passive radiator and a dedicated driver contribute to deeper, controlled bass for a compact speaker. Bluetooth connectivity with an extensive range enables placement farther from the audio source than many portable speakers, while the low weight makes it easy to carry. The product also incorporates practical features such as one-touch playback control and compatibility with multi-speaker pairing via the manufacturer's app.

Suitable for

• Portable music playback at home or outdoors
• Small gatherings and social events where 360° sound is useful
• On-the-go use such as beach, park, or travel where lightweight and durable design is needed

Key specifications

• Driver diameter: 4 cm
• Passive radiator dimensions: 46.1 × 65.2 mm
• Maximum sound pressure level: 85 dB
• Wireless profile: Bluetooth A2DP
• Bluetooth range: up to 45 m
• Weight: 0.62 kg
• Colour: Blue
• Playback control: one-touch play/pause/skip
• Battery life (manufacturer stated): up to 15 hours

How to use

Charge the speaker fully before first use following the manufacturer’s charging instructions. Activate Bluetooth on your audio source, open the device list, and select the speaker to pair via the A2DP profile. Use the one-touch control on the speaker to play, pause, or skip tracks as supported by your streaming app. For expanded setups, use the UE | BOOM app to access preset EQ modes, create one-touch playlists, and pair multiple compatible speakers for synchronized playback.

Usage recommendations

Place BOOM 4 on a stable surface in the central area of your listening space to maximize the 360° sound dispersion. For stronger bass response, position the speaker near a solid surface; for more even room coverage, keep it elevated and clear of obstructions. When using outdoors, maintain a clear line of sight within the stated Bluetooth range for reliable wireless connection.