The $129.99 Anker Soundcore Boom 3i is the epitome of outdoor speakers. It's rugged and waterproof, provides hours of listening time, and travels easily thanks to its compact design and generous carry strap. Special safety features, like an emergency siren and LED lighting, help the Boom 3i stand out. As a speaker, its audio performance is middling, due to overly strong bass and harsh mids. Ultimately, we recommend most adventurers stick to the Anker Soundcore Motion 300 ($79.99), which skips the extras in favor of excellent audio while still providing a tough build and strong battery life, making it our Editors' Choice for outdoor speakers.

Design: Compact and Colorful

The Boom 3i is small enough to be easily portable, at 3.35 by 8.27 by 3.09 inches (HWD) and 1.7 pounds. It's thicker than the Motion 300, which has a more book-like shape, measures 1.97 by 7.87 by 3.64 inches, and also weighs 1.7 pounds.

(Credit: Mark Knapp)

Three control groups are positioned on top of the speaker. The first toggles the power and initiates Bluetooth pairing. The middle section includes volume buttons, a lighting control that cycles through various audio presets, and a play/pause button that also manages track selection. The final cluster has separate buttons for enabling PartyCast (pairing with more speakers) and BassUp (bass boost). Underneath, the unit has two slim rubber feet that run from the front to the back. These help it stand firmly.

The Boom 3i packs an adjustable shoulder strap for easy carrying. Soundcore sells the Boom 3i in black, blue, brown, or the green version shown in this review.

The speaker is rated IP68 for water and dust protection, and is designed to float. The design places more weight on the back side of the speaker, so that the drivers point up and out of the water if it dives into the pool. If you crank the volume, the drivers will eject most of the water.

(Credit: Mark Knapp)

The unit is constructed from sturdy plastics that should withstand knocks and scrapes. A grille protects the tweeter and woofer inside. Despite having two drivers, the tweeter and woofer together produce mono audio, though at a significant 50W. Extended crowns protect the passive radiators at each end.

These radiators generate the light show, thanks to multi-colored LEDs inside that can shine a single color or react to audio. It’s a fun feature, although a bit inconsistent in its response to audio.

It connects via Bluetooth 5.3 and supports the AAC codec, multipoint connectivity, true wireless stereo (TWS) pairing for two speakers, and multi-speaker PartyCast. There's no 3.5mm aux port for wired listening. The 3i also includes some special functions for adventuring, including a 96dB alarm that's activated by holding the BassUp button for five seconds, as well as an amplified voice and message feature accessible via the Soundcore app.

(Credit: Mark Knapp)

Soundcore claims the speaker delivers up to 16 hours of battery life per charge, and I found this to be true in testing. It charges in four hours via the USB-C port on the back, which is protected by a thick rubber gasket and is used solely for charging; it doesn't support wired audio. The Motion 300, by comparison, is rated for 13 hours of playback on a single charge and takes 5 hours to recharge.

App Experience: Unique Features Add Value

The Boom 3i works well with the Soundcore mobile app (available for Android and iOS). While you're encouraged to create an account to use the app, it's not required.

The app's main screen provides a rough estimate of battery life, volume and playback control, a toggle for the Bass Up 2.0 feature, and an equalizer. The equalizer offers a few presets, but also has a user-adjustable nine-band EQ with the option to shift the frequencies you’re targeting. This is great for those who like to take control over the curve.

The Voice Amplifier is a novel feature. It lets you record a message in the app and have the speaker play it on a loop. For example, you can leave a message for friends at camp if you wander off on your own. It supports live amplification, though with a slight delay, allowing you to speak into your phone and have the speaker play it back louder, so people can hear you more clearly. This could be a critical safety tool.

Last, the app includes a white noise generator to play soothing sounds for relaxation, a shortcut to the emergency alarm to signal for help, and a Buzz Clean feature designed to dislodge liquid and debris from the speaker. The Soundcore app is more useful than most.

Sound: Loud, But Lacking Refinement

The Soundcore Boom 3i’s primary function is to deliver fun, energetic sound, and it mostly succeeds. It may not be ideal for critical listening, but it’s a fairly satisfying speaker to have on hand for outdoor activities.

It kicks off The Knife’s “Silent Shout” with promise. The bass triplets and sub-bass quarter notes thump with a satisfying force. When engaged, the BassUp 2.0 feature really does deliver extra bass. The synth melody is loud and clear with a strong attack. There’s an obvious low-end emphasis, though, and it leaves some frequencies a little thin in the mix, including the upper vocal harmony, which fails to stand out thanks in part to the mono presentation.

(Credit: Mark Knapp)

The thin upper register performance impacts Kendrick Lamar’s “Loyalty." For example, the Bruno Mars sample loop is buried in the mix. Kendrick and Rihanna’s vocals are clear, but exhibit a bit too much in the upper mids, taking on a harsh quality that started to give me a headache before long. Soundcore rates the Boom 3i's lower-frequency range at 56Hz, and it reproduces those tones effectively. It sounds clearer with Bass Up turned on, but if you also raise the volume, the speaker starts to rattle. Even with that depth, the 3i isn't up to the task of the deep sub-bass required by “Loyalty.” The song introduces a recurring line around the 35-second mark, but only one note comes through. Instead, the speaker hiccups through the passage in an unfortunate way.

Bill Callahan’s “Drover” fares a little better. Callahan’s baritone vocals are full and weighty, and don’t face the same harsh treatment. The drum rimshots and hi-hat hits can be overly sharp, but their sporadic nature makes them more tolerable. The acoustic rhythm guitar has a solid, low body, and the fiddle shares some of the same energy as the synth melody in “Silent Shout." However, many of the track's dynamics are lost due to the mono presentation here. It feels compressed overall.

(Credit: Mark Knapp)

The Boom 3i is not well-suited for orchestral music. Its sculpted EQ leaves the orchestra too far back in the mix, while the bass overpowers the upper registers. This happens constantly in John Adams’ The Gospel According to the Other Mary. Some of the choir segments are pleasing, but the strings and horns are hard to discern. And with so much sound from the orchestra, the upper-mids are harsh and a near constant presence.