Overview The Sony ULT Field 1 is a rugged, go-anywhere Bluetooth speaker engineered with a single goal: delivering serious bass in a compact package. As the entry point to Sony's ULT Power Sound series, it pairs a single tweeter with a rectangular woofer, while a dedicated ULT button on the chassis pushes the bass further without ever opening an app. An IP67 rating plus a water, dust, rust, and shockproof design means this speaker is built to handle beach trips, job sites, and backyard gatherings without babying it. At just 650 grams with a detachable carry strap, it's light enough to clip to a backpack, and up to 12 hours of battery life covers a full day of casual listening. Simcoe Audio Video Insight We recommend the ULT Field 1 as a rugged step-up from ultra-compact clip speakers for anyone who wants real bass output without carrying something bulky. It's a performance-first portable that prioritizes an energetic sound signature that doesn't get lost in open outdoor spaces. Tip: keep ULT mode engaged when listening outdoors or in large rooms. Turning it off gives a leaner, flatter response better suited to quiet indoor listening, while ULT mode is tuned to compete with wind and ambient noise. More Info Why the Sony ULT Field 1 Stands Out On-Demand Bass The physical ULT button provides an instant boost to low-end frequencies, making it easy to adjust the sound on the fly without opening an app. Water, Dust, Rust, and Shockproof Design Beyond its IP67 water and dust resistance, Sony builds the Field 1 to also resist rust and shock, so it can handle drops and harsh outdoor environments. 2-Way Sound with a Rectangular Woofer A dedicated tweeter keeps high-frequency detail clear even with the bass turned up, while the rectangular woofer design maximizes diaphragm area compared to a traditional circular driver of the same footprint. 12-Hour Battery Life Up to 12 hours of battery life covers a full day of casual listening, with USB-C charging for quick top-ups between uses. Bluetooth 5.3 with Fast Pair Bluetooth 5.3 with Fast Pair gets you connected to Android devices in a single tap, without digging through a Bluetooth settings menu. Stereo Pairing Wirelessly link two ULT Field 1 speakers together to create a wider, left/right stereo soundstage. Sony | Music Center App Support The Sony | Music Center app gives you a 3-band equalizer to fine-tune the sound profile beyond the built-in ULT button. Buyer's Guide Who It's For The active adventurer: Hikers, campers, and beach-goers who need a speaker that can genuinely take a beating and keep playing. The bass enthusiast: Listeners who want an energetic, punchy sound without navigating EQ menus in an app. The value hunter: Anyone looking for a rugged step-up from ultra-portable clip speakers who isn't ready to jump to flagship pricing. How It Compares The ULT Field 1 is optimized for bass and durability in a compact package. If you want a wider soundstage and more overall volume, the JBL Flip 7 is a worthy step up. For the longest possible battery life in a similarly small form factor, the Sony SRS-XB100 offers up to 16 hours of runtime.