Monster S310 Upgraded Bluetooth Speaker - 30W Portable Sound

Our review of the Monster S310 Upgraded Bluetooth Speaker finds it best for listeners who want powerful, portable audio without fuss. The single biggest reason to buy is its combination of clear, deep bass and true wireless stereo pairing, which delivers a room-filling 30W output from a compact, IPX6-rated package. For casual outdoor parties, poolside listening, or moving between rooms at home, the S310 balances portability, battery life and connectivity in a way that makes it a practical everyday speaker.

Key Features

• Pure Monster Sound: Designed and engineered by Noel Lee and the Monster team to prioritize dynamic performance with deep bass punch and low distortion, so tracks retain clarity at higher volumes.
• 30W True Wireless Stereo: Two S310 speakers can be paired to create independent left and right channels for an effective 60W stereo setup that widens the soundstage for parties or movie audio.
• Bluetooth 5.2 Connectivity: Bluetooth 5.2 offers a reliable wireless link and extended range up to about 100 ft in open conditions, reducing dropouts during outdoor use.
• IPX6 Waterproof: The speaker resists splashes and rain, making it suitable for poolside, beach and light shower use without immediate worry about moisture exposure.
• Long Battery Life: A built-in rechargeable li-ion battery provides up to 24 hours of continuous playback at moderate volume, covering a full day of use for work, study or small gatherings.

Who It's For

The S310 is aimed at users who want a portable speaker with a strong focus on sound quality and real-world ruggedness: those who host small outdoor gatherings, take music on bike rides or who need a versatile indoor/outdoor companion. Its stereo pairing makes it attractive to listeners who want a wider soundstage without investing in larger equipment.

It is less suited to audiophiles seeking studio-level accuracy or to users who need IPX7 waterproofing for full submersion. Also, buyers wanting a smart speaker with voice assistant integration or a very compact pocket-sized option should look elsewhere.

Pros & Cons

Pros

• Strong, clear sound with noticeable bass for a portable speaker thanks to Monster tuning and 30W output.
• True wireless stereo pairing doubles effective power and creates a convincing 360 stereo effect for parties.
• Long battery life with up to 24 hours of playback at reasonable volumes keeps music going through the day.
• Bluetooth 5.2 and IPX6 rating make it reliable for outdoor and wet-weather use.

Cons

• No built-in voice assistant or advanced smart features, so control is limited to connected devices and onboard buttons.
• IPX6 resists splashes but does not allow full submersion, which limits pool use if dropped in water.

Specifications

Our Verdict

The Monster S310 is a strong all-around portable speaker that delivers impactful bass, clear mids and a lengthy battery life in a weather-resistant package. It represents good value for buyers who want powerful, portable sound and the option to pair two units for a wider stereo experience, while acknowledging it lacks advanced smart features and full waterproofing for underwater use.

Frequently Asked Questions

Can two S310 speakers be paired for stereo?
Yes, two S310 speakers can be connected via True Wireless Stereo pairing to create left and right channels and boost total output.

How long does the battery last on a charge?
The rechargeable li-ion battery provides up to 24 hours of continuous playback at appropriate volume levels.

Is the speaker safe for poolside use?
The IPX6 rating protects against splashes and rain, so it is fine for poolside use, but it is not rated for full submersion.