Sony ULT Field 5 Review: Lights, Bass, Action—Sony’s Party Machine

Bluetooth speakers come in all shapes and sizes, but the Sony ULT Field 5 doesn’t bother with subtlety. It’s big, it’s loud, and it yearns to be a part of your life (and all the parties that could come and go by). With powerful sound, customizable light rings, and ULT Power Sound modes that promise head-thumping bass, this isn’t your everyday put-in-the-bag, carry-around speaker. But does the massive sound and premium build quality justify the price, or is it simply an overkill for casual listeners? Let’s dig in.

Sony ULT Field 5 Review: Build & Design

While I received a demo unit of the device in a relatively plain and straightforward packaging, inside, I found a USB-C to USB-C cable, a high-quality shoulder strap with “ULT POWER SOUND” engraved on it, and the speaker itself. While my box has plain white packaging all around, the one you receive should be slightly different, featuring the usual key specifications and the company’s branding.

Lifting the device from the box, I noticed a few things immediately: its weight, the chunky yet unflinching design, and the robust build quality. The speaker (including the battery) weighs 3.3 kilograms, which doesn’t help carrying it around much, but the included shoulder strap (adjustable) sure does. Either way, you’d want to be careful while handling it.

Regarding design, the Sony ULT Field 5 has a premium and upmarket feel. It is certainly bigger and heavier than some other speakers in the segment, but that isn’t a mistake (we’ll discuss it in the sound quality section). The seamless fabric mesh runs throughout the cylindrical speaker, while the passive radiators on either side have a rubberized casing and a polycarbonate exterior.

The device features its controls at the top, including dedicated buttons to power it on/off, a Bluetooth button for pairing the device, a dedicated “Connect” button for the Party Connect feature, and three buttons for playing/pausing, increasing, and decreasing the volume. You also get an illuminated ULT button for switching between pre-programmed sound modes.

At the bottom, the speaker features four anti-slip silicon pads to provide a stable grip on a surface. So far, the speaker’s exterior might sound a bit too simple and elegant, but the hidden light rings around the passive radiators add just the required amount of flashiness and show. Via the Sound Connect app, you can switch between four available lighting modes: Off, Beat, Wave, and Mellow.

On the back, the device features a rubber flap that seals the USB-C and audio port, along with buttons for battery care and the lights. The official IP66 and IP67 ratings also contribute to the robust build quality of the speaker. Hence, you can wear the device on your shoulder (with the strap), and carry it around parties in the open without fearing accidental spills or light rain.

Sony ULT Field 5 Review: Sound Quality

The ULT Field 5 contains two front-firing tweeters (46 mm), one X-Balanced woofer (79 mm × 107 mm), and two passive bass radiators on either side. With the combination of tweeter and woofer, the speaker produces a rich, balanced, and loud (yet clear) sound, with a slight emphasis on bass. The overall audio quality is excellent, and the loudness is sufficient to fill a large living room or a small hall.

The bass response is one of its standout features; you can physically feel it in small to medium rooms. However, the main highlight of the device is the ULT power sound modes.

• Pressing the ULT button once engages ULT1 (deep bass) mode, which accentuates the low end and adds weight to the sound, generating thumping bass.
• Pressing the button again enables ULT2 (powerful mode), which adds more kick to the sound, vocals, and the bass, altogether, resulting in a balanced yet energetic sound that enhances every genre.

Moreover, the ULT modes aren’t just a gimmick, as they change the overall character of the Bluetooth speaker, but like every other speaker, the ULT Field 5 isn’t entirely free of flaws. Its default sound signature positions mids and highs with enough clarity and detail, but the enhanced bass in the ULT1 mode bleeds into the mid-range a bit, making vocals and instruments sound a bit recessed. Even in ULT2 mode, I feel that the vocals are slightly overshadowed.

Although you might not use the device at maximum volume levels all the time, depending on the song you’re playing, you’ll notice a slight drop in clarity. However, this is a common issue with many Bluetooth speakers. Since it’s a front-firing speaker, you need to be directly in front of it to get the best audio experience.

Nonetheless, the speaker offers features like Sound Field Optimization that detect ambient noise and automatically adjust the sound settings to enhance clarity in any environment, Stereo Pair for connecting two ULT Field 5 speakers for activating stereo sound (with a more expansive soundstage), and a Party Connect Mode that lets you connect up to 100 compatible Sony speakers.

Sony ULT Field 5 Review: App & Features

While you can pair the speaker using the Bluetooth settings menu on your Android or iOS device, you will need to download the Sony Sound Connect app (308.4 MB on the App Store) to unlock all the additional features and device settings. On the home screen, the app shows the remaining battery life of the speaker, with the codec it’s currently using (AAC for me; the official documents also mention support for LDAC).

Using the app, you can connect the speaker simultaneously with two devices, change the audio source (via Bluetooth or wired connection), control music playback (along with volume), and change the device settings, such as the ULT sound effects, Sound Field Optimization, and Bluetooth connection quality (between prioritizing sound quality and prioritizing stable connection).

After installing an OTA update, I’m using version 12.2.0 of the Sony Sound Connect app, and it also provides the DJ Control and Party Light features. The DJ Control feature lets you add several effects to the sound, personalize the audio quality via a 10-band equalizer (the device responds well to adjustments), and, my personal favorite, the Isolator feature, which does an excellent job of separating and highlighting specific frequency bands.

Then there’s the Party Light feature that provides a granular control of the ambient lights on the speaker using an on-screen light wheel. The System settings menu also includes Battery Care, which limits the fully charged battery to around 90%, and a dedicated Stamina mode that prioritizes battery life. The app isn’t exactly intuitive and hides some of the most highlighted features, such as the ULT sound modes, deeper within the Device settings menu, but it gets the job done.

It’s worth mentioning that the speaker doesn’t have a microphone for hands-free calling.

Sony ULT Field 5 Review: Battery Life & Charging

The claimed battery life of the Sony ULT Field 5 is 25 hours. However, I ended up using 80% of the battery in five to six days, using the speaker for around two to three hours every day, with the ULT2 mode enabled, Stamina mode disabled, and prioritizing sound quality (all these settings take a toll on the battery life).

The speaker also supports fast wired charging, which provides up to 100 minutes of playtime with 10 minutes of charging. What’s good is that it charges via a USB-C port, which is likely already supported by your other devices (so you won’t need to carry a separate cable for the speaker).

Review Verdict: Should You Buy the Sony ULT Field 5?

The Sony ULT Field 5 is a beast of a Bluetooth speaker design for those who want room-filling, bass-heavy sound wrapped in a rugged, party-ready shell. Its ULT sound modes genuinely enhance the listening experience, and features like Sound Field Optimization, Party Connect, and stereo pairing mode.

Bass lovers who want deep, thumping low-end, party hosts needing loud, room-filling sound, and outdoor users who wish to have a rugged build can purchase the speaker without second doubts, provided you have the budget. However, people who value portability over power, audiophiles seeking vocal clarity, casual listeners who just need background music, or anyone looking for a compact speaker in a budget might want to consider other options.

Smartprix ⭐ Rating: 8.15/10

• Design & Build: 8.0/10
• Portability: 7/10
• Sound Quality: 8.75/10
• Apps & Features: 8.5/10
• Battery Life & Charging: 8.5/10

First reviewed in September 2025.

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