Our verdict, based on published evidence: the Sony ULT Field 1 is a bass-first outdoor speaker — ecoustics found it louder and bassier than the Sonos Roam, and owners rate it 4.6/5 on Amazon. Caveat: Sony's 12-hour battery claim assumes moderate volume; testers measured 3–4 hours at half volume with ULT on. Check the current price on Amazon.
— THE VERDICT · JUDGEANY EDITORSA pocket bass cannon with fine print
The Sony ULT Field 1 — model SRS-ULT10 — arrived in April 2024 as the smallest member of Sony's ULT Power Sound family, a 650-gram box built around one idea: press the ULT button and the bass shows up. Inside are a 16mm tweeter, an 83×42mm X-Balanced woofer, and two side passive radiators, all wrapped in an IP67 shell with a detachable strap. It launched at $129.99; by October 2026 it was selling far below that — Kotaku reported an Amazon price of $68 after the Prime Big Deal Days, calling it a clearance. Check the current price on Amazon before you buy. We don't run a test lab: every measurement and impression below belongs to the outlet or owner that published it, and the score is our editorial judgment based on that public evidence.
Sound: bass first, everything else second
The Field 1 is tuned for bass, and everything about it follows from that. ecoustics compared it directly against the Sonos Roam and found the Field 1 louder and bassier, the better pick outdoors or in a big room — while conceding the Roam's vocals sound clearer indoors. The ULT button is a single on/off stage, not the two-stage version on the ULT Wear headphones, and it defines the sound: ecoustics measured a recessed midrange with ULT engaged and bass that can bloat on some tracks, while DANAMIC — which scored it 7.5/10 — called the non-ULT sound "rather middling." Android Police put it bluntly: "If you're an audiophile, stop reading — this speaker is decidedly not for you." Two spec-sheet realities shape expectations: the codecs are SBC and AAC only, with no LDAC, and the Sony Music Center app's custom EQ can't run at the same time as ULT mode.
Battery: the 12-hour number needs context
Sony's spec sheet rates the Field 1 for about 12 hours, and that number is real — under Sony's conditions. Tom's Guide's hands-on found roughly 12 hours at 25% volume with ULT on, but closer to 3 hours at 50% with ULT enabled. DANAMIC landed in the same place: 3–4 hours at half volume. Stiftung Warentest, the German testing body, measured under eight hours and called it "rather poor." The honest read: this is an all-day speaker at background volume and a half-evening speaker at party volume. On the charger side, ecoustics measured about 5 hours for a full charge on a 1.5A adapter — and don't count on fast charging, which Sony's own comparison table doesn't list for the Field 1.
Built for the trail
The ruggedness claims are the least disputed part of this speaker. IP67 means dust-tight and survivable to a meter of water for 30 minutes; Sony adds rustproofing and shockproofing rated for roughly a 3-foot drop, and ecoustics dunked one without incident. The detachable strap and 650-gram weight make it genuinely portable, and two units can form a stereo pair. The notable absence: no Party Connect, so you can't chain a crowd of them — that feature starts with the bigger Field 7. There's a built-in mic with echo cancelling for hands-free calls, a small bonus most trail speakers skip.
What owners actually say
Owners rate it 4.6/5 on Amazon across roughly 2,900 reviews, and the praise clusters exactly where you'd expect: big bass for the size, the useful strap, true waterproofing, and a price that undercuts comparable JBLs. The complaints are consistent too. The top critical review on Amazon is titled "Not loud enough." Several owners find the ULT bass overpowering rather than fun, and Brian MacDuff's video review notes the sound degrades past about 70% volume — his sweet spot is 50–60%. Taken together, the owner consensus matches the media consensus: a likeable bass box with a volume ceiling.
Who should buy it
Buy the Field 1 if you want a genuinely portable, genuinely waterproof speaker that leans into bass — for the beach or the campsite, it's an easy recommendation at the street prices seen in October 2026 ($68 on Amazon after the Prime Big Deal Days per Kotaku; $108 per speakerranking's tracker). Skip it if you need room-filling volume, all-day battery at high volume, or neutral sound. The ULT button is the whole pitch. Bass heads should buy it; everyone else should keep looking.