The Sony ULT Field 5 is the newest heavyweight in Sony’s rugged, portable Bluetooth speaker arena. Stepping in as the successor to the excellent SRS-XG300, it’s a larger sibling to the smaller ULT Field 1 and ULT Field 3, yet it manages to be more budget-friendly than the model it replaces. Despite the lower price tag, the ULT Field 5 doesn’t skimp, bringing back the vibrant light show and introducing some exciting new features. Get ready to hit that ULT button—which Sony promises will deliver “Powerful Bass”—as we dive into our in-depth Sony ULT Field 5 review.
Read: Samsung Galaxy Tab S10 FE Review: Mid-range makes sense
The ULT Field 5 is built for rugged portability, featuring a durable, IP67-rated chassis that can handle dust, water, and even float. Beyond its tough exterior, it stands out with its ULT Power Sound modes for instant bass tuning, supports LDAC for high-resolution audio, and—unlike its smaller siblings—delivers true stereo sound. Complete with room correction, a lengthy Stamina battery mode, and a convenient carrying strap, this speaker is ready to be your all-night, poolside companion.
Design & Build
The Sony ULT Field 5 takes the familiar rectangular aesthetic of the Field 3 and scales it up. At approximately 14.5 by 32.0 by 12.5 cm and 3.3 kilograms, it occupies a comfortable middle ground between its smaller sibling (11.2 by 25.7 by 7.9 cm, 1.2 kg) and the much larger, cylindrical Field 7 (22.4 by 51.3 by 22.1 cm, 6.3 kg).
The build feels solid, wrapped in a mesh textile and flanked by a passive radiator on each end. We reviewed the most common black model, though the only other colour available is White. Both radiators are encircled by customizable LED lighting that adds a bit of personality to the otherwise muted tone. Crucially, the speaker boasts an IP67 rating, confirming it’s fully protected against dust, dirt, and brief submersion in shallow water.
A thoughtful design touch is the integrated strap system: small rubber inserts on the top surface can be easily removed and flipped to expose loops for the included shoulder strap, keeping the top surface flush when not in use.
All essential controls are located on the top panel. These include the standard buttons for power, pairing, volume, and playback. The star, however, is the prominent ULT button, which cycles the bass effect between off, ULT 1 (a boost to the lowest bass frequencies), and ULT 2 (a tighter, more punchy bass).
The ULT Field 5 provides enhanced connectivity compared to the Field 3. The rear panel features a USB-C port for both charging the speaker and acting as a power bank for your devices. A welcome addition is the 3.5mm AUX port for wired input, which the Field 3 lacks.
Wirelessly, the speaker uses Bluetooth 5.3 and supports both Fast Pair and multipoint connections. It also includes Sony’s Party Connect feature, allowing you to stereo pair two speakers or link up to 100 Sony units; note that it does not support the newer, brand-agnostic AuraCast standard.
The ULT Field 5 supports the AAC, SBC, and high-resolution LDAC codecs, the latter being a significant upgrade over the Field 3. Audio is delivered through two tweeters and a single 10.7 by 7.9-centimeter racetrack woofer, supported by the two passive radiators. Thanks to the separate tweeters, the Field 5 outputs true stereo audio, and it’s capable of reproducing a frequency range of 20Hz to 20kHz.
Sony claims an impressive battery life of 25 hours, which is quite good for a speaker of this size. This longevity means moderate users can easily go days between charges. When a top-up is needed, a 10-minute charge can provide two hours of playback time.
App Experience
Advanced customization and fine-tuning for the ULT Field 5 are handled within the Sony Sound Connect app. This is where you’ll find the comprehensive 10-band equalizer, complete with a variety of sound presets, alongside full control over the integrated lighting effects. The app also includes fun DJ sound effects, a feature familiar from the larger ULT Tower 9AC.
A standout technical feature is the Automatic Sound Field Optimization. Using measuring microphones built into the speaker itself, this function automatically adjusts the frequency response of your music to best suit the environment, whether you’re in a lively living room or an open green field. While it’s activated by default, you do have the option to deactivate this optimization within the app settings.
However, the experience of starting with the app was frustratingly slow. Setup required clicking through what felt like an endless chain of license agreements and intrusive access requests—like asking if “Sound Connect can record your activities in apps and on websites of other companies.”
This was immediately followed by installation hurdles when attempting the standard firmware update. Despite the speaker having battery life remaining, the app (available for both iOS and Android) repeatedly demanded the speaker be connected to a charger. Even after plugging the ULT Field 5 in, I was further blocked because the update wouldn’t proceed until my phone’s battery level exceeded an arbitrary threshold, despite being above 20%. The sheer concentration of mandatory steps and restrictive requirements during initial setup was something I hadn’t encountered before.
See also
Audio Performance
The most compelling reason to choose the ULT Field 5 over the Field 3 is its significantly improved bass performance. Equipped with a larger woofer and correspondingly bigger passive radiators, the Field 5 delivers a deeper, more substantial, and rounder low-end sound than its smaller sibling.
The enhanced bass response makes a tangible difference on tracks heavy with deep sub-bass synthesis, adding palpable depth to the mix. While the speaker doesn’t reach the absolute lowest bass frequencies—a feat usually reserved for much larger systems like the Sony ULT Tower 9—it performs admirably for its size, easily surpassing the Field 3 and many other compact speakers. However, this powerful low-end occasionally threatens to dominate the higher frequencies, sometimes reducing the prominence of percussion and other high-register elements.
When handling music that features complex sub-bass lines, the Field 5 manages to capture many of these low notes, providing an underlying depth that is often completely missing in portable speakers of a similar size. The midrange presentation helps prevent the bass from completely muddying the mix; vocals, while rich and deep, possess a slightly subdued or “lo-fi” quality, sometimes lacking the sharp sibilance needed to truly cut through the soundscape.
For tracks emphasizing natural tones and simple arrangements, the speaker excels at providing a rich texture to baritone vocals and highlighting the impact of a driving kick drum. Conversely, instruments residing in the highest register, like acoustic guitars and cymbals, often lack the necessary sparkle and presence to feel fully detailed.
While the Field 5 technically supports stereo playback, the close proximity of the tweeters—separated by mere centimetres—means the actual stereo effect is minimal. This narrow staging, combined with the slight lack of high-end extension, can make complex orchestral or heavily layered tracks feel somewhat crowded, as if various instrument sections are stacked rather than spread across a wide soundstage. Despite this, the strings maintain a relatively rich tone and the brass registers with decent brightness, providing a welcome balance to the powerful bass foundation.
Conclusion
The Sony ULT Field 5 is a solid and easy-to-recommend choice for anyone who prioritizes ruggedness and wants the option for heavy bass on demand. It earns its place above the Field 3 by offering significant technical upgrades, including hi-res LDAC audio support and a 3.5mm AUX wired input. Add in the excellent 25-hour battery life, customizable LED lighting, and a comprehensive in-app EQ, and you have a speaker that performs well beyond just its portability.
Ultimately, the ULT Field 5 is an excellent mid-range party speaker built for the outdoors.
