Description
The Sony ULT Field 1 is a compact portable Bluetooth speaker, model number SRSULT10B, built around a single headline feature: a physical ULT button that switches the speaker into a bass emphasized mode. Sony pairs that with an IP67 rating, a 12 hour battery figure and a detachable strap, and positions it for showers, pools, parks, gyms and camping trips.
At 4 by 4 by 9 inches and 1.43 pounds it is genuinely portable, which distinguishes it from larger rugged units like the Altec Lansing Super LifeJacket Jolt or the JBL Charge 5. Those carry bigger batteries and more output. This one is designed to be strapped to a bag and forgotten about.
The ULT Button And Sound Processing
Sony describes the ULT button as unleashing deep, resonant bass, which in practice means a preset equalizer curve that lifts the low end. Whether that is an improvement depends entirely on taste and on the source material, and Sony publishes no frequency response figure to quantify what the mode changes. A small enclosure has physical limits on how much low frequency energy it can produce, so a bass mode on a speaker this size is boosting what is there rather than extending the response downward.
Sony also credits a sound diffusion processor using DSP technology, which it says fills a space and creates an immersive experience. That is a processing claim rather than a measurement. The driver arrangement is more concrete: the listing gives a woofer diameter of 1.7 inches and a tweeter diameter of 0.6 inches, which is a sensible two way layout for a speaker of this size. Confusingly, a separate Speaker Size field reads 16 millimeters, which matches neither figure.
Durability And Portability
IP67 means the enclosure is sealed against dust ingress and can withstand immersion in one meter of water for up to 30 minutes. Sony extends the description to rustproof and shockproof, which points to corrosion resistant hardware and a housing designed to survive drops. The Is Waterproof field reads True and the Water Resistance Level field reads Waterproof, so the data is consistent on this point.
The detachable multi way strap is the practical portability feature. Sony frames it as letting the speaker be hung from a hook or a branch, held in the hand, or secured to a bag, and the strap is listed among the included components along with a USB Type-C cable in an A to C configuration. Note that the cable is A to C, so charging from a modern C only laptop charger requires a different cable.
Battery, Range And Pairing
Sony rates the battery at 12 hours and lists the capacity at 2900 mAh. Battery figures on Bluetooth speakers are always quoted at a moderate volume, and running the ULT bass mode at high volume will draw more current, so 12 hours should be read as a ceiling rather than an expectation. Sony does not publish a figure for runtime with ULT engaged.
Wireless range is given two different ways in the listing. The Maximum Range field reads 30 meters and the Bluetooth Range field reads 10 meters. Ten meters is the standard Class 2 Bluetooth figure and 30 meters is the optimistic open air figure, and the listing does not reconcile them. A second matching speaker can be added for stereo playback, and a built in microphone with echo canceling handles hands free calls. Four colors are listed: Black, Off White, Forest Gray and Orange, with this listing covering the black version.
Highlights
- ULT button for a bass emphasized listening mode.
- IP67 rated enclosure, described as waterproof, dustproof, shockproof and rustproof.
- 12 hour rated battery from a 2900 mAh cell, charged over USB Type-C.
- 1.7 inch woofer with a 0.6 inch tweeter.
- Detachable multi way strap included.
- Stereo pairing with a second compatible speaker.
- Built in microphone with echo canceling for calls.
Things To Consider
The listing data carries several errors that are worth naming rather than smoothing over. Mounting Type is given as Floor Standing on a speaker with a carry strap. Unit Count reads 1.0 Ounce while Item Weight reads 1.43 pounds. Number of Batteries reads one A battery required and included, on a product that plainly uses a built in rechargeable lithium cell of 2900 mAh. Control Method reads Touch while the entire product description is built around a physical button. None of that changes what the speaker does, but it means the specification block cannot be trusted line by line.
The marketing copy is also unusually keyword heavy, repeating phrases like shower speaker bluetooth waterproof and portable bluetooth speakers in nearly every sentence. That is search optimization rather than product information, and buyers should read past it to the actual figures.
No power output rating appears anywhere, so there is no way to compare loudness against competitors on paper. A speaker this size will not fill a large outdoor space, and buyers who need volume should look at a larger unit. Customer feedback is good and reasonably well sampled at 4.6 stars across 1,807 ratings, on a listing first available in April 2024. Readers comparing alternatives can browse the full portable Bluetooth speakers category, including the Ultimate Ears MEGABOOM 4, or look at the computer speakers category for a desk bound alternative.
Who It Suits
The ULT Field 1 suits someone who wants a genuinely small speaker that survives water and drops, listens mostly to bass forward music, and values being able to clip the speaker to a bag or hang it in a shower. The strap, the IP67 rating and the 12 hour battery together make it a practical travel and outdoor companion rather than a home audio product.
It is the wrong speaker for filling a large room or an open yard, for listeners who want a neutral tuning rather than boosted bass, and for anyone who wants to compare measured output before buying, since Sony publishes no wattage or frequency response for this model. A larger portable speaker will go louder and play deeper.
