Verdict
The Sony ULT Field 5 neatly bridges the gap between super-sized party speaker and portable Bluetooth speaker. It’s immensely powerful, but you can still lug it about without needing to visit the chiropractor
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Mega powerful -
Relatively compact -
Bassy sound with great vocals -
Can sync with other Sony speakers -
Bluetooth Fast Pair and Multipoint
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Lighting is underwhelming -
App layout is confusing -
It’s quite heavy
Key Features
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Unexpectedly powerful
Being a more compact speaker, I thought the ULT Field 5 would be much weaker than its full-sized counterparts, but that’s not the case -
Super quick pairing with Android
The inclusion of Google Fast Pair means connecting this speaker to an Android phone is incredibly quick and convenient -
Convenient carry strap
Sony includes a nifty shoulder strap to make it easier to lug about.
Introduction
Sony’s ULT Power Sound line-up aims to get the party jumping at every size and price point. This site has tried everything from the hulking great Tower 9AC to the pint-sized Field 1, but yet to get our hands on the middle-child, the Field 5.
As the name suggests, the Field 5 occupies the middle ground between Sony’s large floor-standing party speakers, and ultra-portable options like the Field 1. If regular Bluetooth speakers aren’t powerful enough for your needs, but you don’t want to make the jump to a dustbin-sized monster speaker, this could be the perfect choice.
The Sony ULT Field 5 has a slick minimal design, a detachable shoulder strap, integrated RGB lighting and, most importantly, tons of raw power. I’ve listened to it for a week, and here’s what I think.
Design
- Removable shoulder strap
- Integrated RGB lighting
- 3.5mm AUX input and USB-C
The Sony ULT Field 5 is a lot larger than your typical Bluetooth speaker, but it’s a lot smaller than your average party speaker. It’s roughly the same size as a loaf of bread, but it’s much heavier, tipping the scales at 3.3kg.
The size means it’s relatively portable, but most speakers of this size feature an integrated carrying handle, and this one doesn’t. This means it’s quite awkward to manoeuvre, but thankfully, Sony includes a detachable shoulder strap in the box, and with that attached, the design feels much more logical.

The method for attaching this strap is very clever, too. When it’s not attached, the fixings are hidden under rubberised flaps on the top panel, but they can be pulled out to reveal sturdy nylon loops underneath. The strap attaches with some thick metal G-hooks, and they’re very quick to affix and remove, which is always a plus.
The speaker is available in either black or white, and I have the black model in for testing. The main body of the speaker is covered with a fabric mesh material, while the buttons are covered with a soft-touch rubbery coating. The design reminds me of the UE Megaboom, just without the supersized volume controls.


The speaker can be used in either horizontal or vertical orientation. There are four small rubber feet on the base to keep it planted, while each side has a rubberised ring that does the same job when the speaker is stood up on one end.
There are sizable passive radiators on the left and right sides of the speaker, and they visibly vibrate along with the beat. Each is encircled with an RGB LED ring to provide some ambient lighting, these LEDs can be customised using the companion app, and they’ll also pulsate along with your music.
The ULT Field 5 feels extremely solid and well-constructed, I haven’t subjected my sample to much abuse, but I can imagine it’ll take a few knocks without issue. It’s also IP67 rated, which means it isn’t fazed by dust, and it’ll handle brief submersion in water, if you have a mishap at the next pool party.


Features
- Sony Sound Connect App
- Bluetooth Fast Pair and Multipoint
Setting up the ULT Field 5 couldn’t have been easier. It supports Google Fast Pair, which means the first time I turned it on, a notification popped up on my Android phone asking if I wanted to pair. I tapped connect, and it was immediately ready to pump out the tunes. Bliss.
The speaker works with Sony’s Sound Connect app (available on both Android and iOS), and you’ll want to get that installed to take advantage of all the available features.


The app looks a little barebones visually, but it includes everything you’re likely to need. There’s a source selector, music controls, EQ options, lighting modes and even a DJ mode that lets you add play sound effects and add filters to music.
The lighting controls are a little confusing. The default mode cycles through a rainbow of colours and pulsates along with the beat. In the app, you can choose a specific colour, but it seemed like it would always be the same music-reactive mode with no additional controls.
It was only after digging a little deeper that I eventually stumbled across more lighting options in the Device Settings and System submenu. It’s such a weird place to put these controls, but regardless, you can choose between Beat, Wave and Mellow options, or you can turn the lights off.


All three modes are music-reactive; the modes just change the intensity of the flashing. I would have loved to see more options here. Sony’s lighting looks decent enough, but it’s an area where this speaker lags behind much of the competition.
When it comes to inputs, the ULT Field 5 is somewhat limited. It’s clearly designed to be used with Bluetooth primarily, but you do get a 3.5mm AUX input for connecting sources. For most people, these options are more than enough, but if you’re hoping to play music from a thumb drive or SD card, you’ll need to look elsewhere.


I was pleased to learn that the speaker supports Multipoint connection. This means you can connect two Bluetooth sources at the same time, and switch between them seamlessly without needing to re-pair. I used it with my phone and laptop, and no matter which device I played music on, it would come through the speaker, it’s pretty handy.
The Sony ULT Field 5 can wirelessly pair with other Sony speakers using the connect button on the top panel. You can synchronise up to 100 speakers in this mode, but unfortunately, this was the only Sony speaker I had on hand, so I wasn’t able to try it out.
If you happen to have two ULT Field 5’s you can connect them as a Bluetooth stereo pair with proper left and right channels, but that’s not something I was able to try either.
Battery Life
- Up to 25 hours
- Works as a powerbank
The ULT Field 5 claims up to 25 hours of playback on a charge. I’ve been listening to it frequently for the past week, and it shows no signs of dying anytime soon, so this seems like a realistic claim.
This boombox will outlast most parties, so you might want to use the battery to top up your phone. There’s a single USB-C port on the rear that’s used to charge the device, and it can also charge other devices. With just a 5V 1.5A output, it’s not the fastest charger around, but it could prove handy in a pinch.
Sound Quality
- Super powerful output
- Dual 46mm tweeters and X-Balanced woofer
- ULT Power Sound bass booster
The first thing that struck me about the Sony ULT Field 5 is how insanely powerful it is. Sony classes this as a party speaker, and given the smaller size, I assumed it wouldn’t get anywhere near as loud as a floor standing equivalent – but I was mistaken.
Even at around 50% volume, this speaker was verging on obnoxiously loud. If you want something compact that compete with the din of 30 or so party attendees, this could very well be the tool for the job.


The speaker has three preset sound modes: ULT 1, ULT 2 and ULT Off. There’s also a 10 band custom EQ, if you’d like to take matters into your own hands. Sony says ULT 1 “enhances the deeper low-pass range” while ULT 2 “has an increased sense of power”.
After some extensive listening with each mode, to my ears, nothing comes close to ULT 2. So I left that on most of the time. I tried my hardest, but I couldn’t come close to replicating the sound with the custom EQ, either, there’s some magic happening with ULT 2 mode.
I felt that the ULT 1 mode boosted the lower-mid frequencies too much, making songs sound too thumpy and muddying the vocals. The ULT 2 mode just brings the speaker to life, there’s more oomph in the sub-bass and the highs sound more crisp and detailed. With ULT mode off, the speaker just sounds a little gutless.


No matter which mode you choose, the speaker has a playful and lively sound signature. It’s sure to appeal to bass fiends more than audiophiles. It’s far from flat, but I don’t think that’s a problem with a speaker like this. It’s not supposed to be a reference device, it’s supposed to get party goers on their feet, and the deep, punchy bass and sparkling highs will do exactly that.
I was pleasantly surprised by the vocal clarity in ULT 2 mode, as well. Despite having a pretty aggressive bass boost, this mode really brings vocalists to the forefront, and the clarity is better than most of the competition. I found this to be true across a variety of genres, too.
No matter your music preferences, there’s a good chance you’ll like the way this speaker sounds. I threw everything at it from mellow acoustic tracks to hip hop, drum and bass and metal, and they all sounded equally great.


Should you buy it?
You want big power in a relatively small package
Few speakers this size can match the thunderous output of the ULT Field 5. If you need something loud enough to compete with your party guests, but don’t want a massive tower speaker, this is a great choice.
You’re want impactful lighting effects
The LED lighting isn’t the brightest or most exciting, and the customisation options in the app are quite limited, too. The lights are nice to have, but competitors are way ahead of Sony on this front.
Final Thoughts
There’s a lot to like about the Sony ULT Field 5, but the best thing is probably the size to power ratio. This speaker manages to remain quite compact and portable, while kicking out a huge sound that competes with some floorstanding party speakers.
If you need serious power, but you don’t want to lug around something massive, this is a great option. It sounds excellent, looks the part, and comes at a reasonable price, too.
There’s no shortage of competition in this area, but Sony still manages to stand out with its compact form factor. The Anker Soundcore Boom 2 Plus and Tribit Stormbox Blast 2 are two other great options with similar output power (and more impressive lighting) but both are significantly larger and heavier than the Field 5. If portability is your main concern, there’s a clear winner.
How We Test
We test every wireless speaker we review thoroughly over an extended period of time. We use industry standard tests to compare features properly. We’ll always tell you what we find.
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Find out more about how we test in our ethics policy.
- Tested for a week
- Tested with real world use
FAQs
Yes, the ULT Field 5 can pair with up to 100 other Sony speakers using the Party Connect feature. It can also be used in a wireless stereo pair with a second Field 5.
Sony claims up to 25 hours of music playback on a charge, but that’s at 20% volume with the lights turned off. If you crank it up with the lights on, it’ll be far less than that.
Full Specs
| Sony ULT Field 5 Review | |
|---|---|
| UK RRP | £199 |
| Manufacturer | Sony |
| IP rating | IP67 |
| Battery Hours | 25 |
| Size (Dimensions) | 320 x 125 x 144 MM |
| Weight | 3.3 KG |
| ASIN | B0DY9X655Q |
| Release Date | 2025 |
| Audio Resolution | SBC, AAC, LDAC |
| Driver (s) | 46mm tweeter, 79 x 107mm woofer |
| Ports | USB-C, stereo mini-jack |
| Connectivity | Bluetooth 5.3 |
| Colours | Black, Off White |
| Frequency Range | 20 20000 – Hz |
| Speaker Type | Portable Speaker |
