Sony ULT Field 7: bass behemoth
Product test

Sony ULT Field 7: bass behemoth

David Lee
Translation: Julia Graham

The Sony ULT Field 7 ticks the party speaker box by setting the mood with powerful bass. It can withstand a lot, and offers interesting extra features.

Before putting it to the test, I was told that the ULT Field 7 is the middle child of three new Bluetooth speakers. I was surprised during unboxing, as it measures over half a metre and weighs over 6 kg. How can this be the mid-range model? It turns out that, as well as the ULT Field 7, there’s also the ULT Tower, a 29 kg monster. Both are categorised as party speakers, so they should pack plenty of power and, above all, powerful bass. However, only the ULT Field 7 has a rechargeable battery, making it mobile. Thanks to the large, sturdy handles, it’s easy to carry.

The Sony ULT Field 7 is… big.
The Sony ULT Field 7 is… big.
Source: David Lee

Sound: bass, more bassy, the bassiest

The ULT Field 7 is bass heavy, which it should be, given it’s marketed as a bass monster. The mids and trebles also come out well as long as I place the unit roughly in a listening position and don’t just put it on the floor.

As always, the sound is heavily dependent on the speaker’s position. It’s designed in such a way that I can also place it upright. In a lot of situations, there’s no other option given it’s so big. This destroys the stereo function, as left and right then become top and bottom. However, the stereo sound is only slight. According to Sony, you can also connect two speakers in stereo. The stereo effect would then be much clearer, and the upright position wouldn’t pose a problem. As I only have one ULT, I can’t put this to the test. The same goes for the multi-room feature.

The bass booms much more when upright than in a horizontal position. This is because one of the woofers is no longer exposed and instead is just above the floor, which reflects the sound. I find this annoying, but then again, I’m not the target group for this device. Some people would certainly consider this feature a plus point.

The passive radiators are upright, located at the top and bottom and adorned with RGB lighting.
The passive radiators are upright, located at the top and bottom and adorned with RGB lighting.
Source: David Lee

But that’s not all about that bass – there’s more to the story. The ULT button boosts the bass in two different ways. Pressing it once produces particularly deep bass, while twice gives loud bass. Sony is true to its word, but it’s worth pointing out that, to a lesser extent, high frequencies are also amplified, not just the bass. This is probably so it doesn’t sound too muffled. The button is at most suited to hip-hop and EDM, but it’s a nightmare for a lot of other genres.

According to its technical specs, the ULT Field 7 can reproduce bass from 20 Hz, but I wouldn’t count on it. In tests, the device got really loud from around 45 Hz. Under 30 Hz, the sine wave test tone also sounds strange, as you can hear in this video.

Own vocals and instruments

I was particularly curious about the 6.3 mm jack plug for connecting a microphone or instrument. The speaker can also be used as a karaoke system or for presenting at events. You can even amp up the vocals with an echo. Don’t worry, I’m not singing in the video – just demonstrating the echo effect.

I can change the volume of the vocals independently of the music using gain control.

It’s the same input for instruments. The Guitar button increases the input impedance so that it doesn’t distort – guitars generate much stronger signal than microphones. However, guitars don’t sound good through the speaker; they require special guitar amplifiers or an upstream amp simulator. But electric basses also work with it directly.

Do you find yourself wanting to sing along to a song but the pitch doesn’t quite match? No problem, you can adjust the music that’s playing. Six semitones higher or lower cover all keys, without changing the speed. The quality is amazingly good. However, the pitch change only works if the sound comes via Bluetooth.

Outdoor skills: bring on the storm

The Sony ULT Field 7 is certified with protection class IP67, meaning it’s dust- and waterproof. It can therefore also be used at a barbecue, followed by a thunderstorm.

The connections are hidden under a thick protective rubber flap. Pulling them out and pushing them back in is anything but easy, but it’s probably needed to make sure the device is waterproof under the flap.

Numerous buttons and connections are hidden under the rubber cover.
Numerous buttons and connections are hidden under the rubber cover.
Source: David Lee

Sony says the battery lasts an impressive 30 hours, but I can’t vouch for how accurate this is. During its short test period, the 5,200-mAh-capacity battery wasn’t even close to being empty.

Equally, I didn’t test how loud the ULT Field 7 is outdoors – suffice to say it’s loud enough. In any case, when I play it in my living room, I feel like I’m at a concert. What I would urge is that you use this device responsibly. Just because you can play loud sound in the most remote places doesn’t mean you have to. Even in nature reserves, there’s more and more noise, which causes considerable stress for animals – and also for people looking for peace and quiet.

The app: some good ideas, but still in its infancy

The Music Center app offers a number of additional features over and above the usual device controls. You can choose from nine different RGB lighting options. As well as the two ULT modes, there’s also a sound setting that you can customise yourself via the EQ. It’s actually great, but even if I set all the bass bands to minimum, this setting is still louder than the default sound. I hope this is a bug and not intentional. The two built-in DJ sound effects also seem rather beta to me. Switching them on and off doesn’t work every time, and there are annoying interruptions.

In a nutshell

Good for parties; bad for neighbours

I actually don’t like it when bass sounds are pimped up in post. But the Sony ULT Field 7 is a party speaker, and as such, it has to deliver – which is exactly what it does. However, I can’t work out how ULT mode is better than any other bass boost. On the plus side, when correctly set up, it produces a sound that’s also usable without an ultra-boost and not the stereotypical «boom boom boom». It also boasts a wide range of connection options. I think it’s cool to be able to feed in vocals or an instrument and adjust the pitch to the music. Even large amounts of water don’t harm the speaker, and its battery life is long enough for unrelenting party animals.

ULT Field 7, you must be fun at parties. For once, I don’t mean this ironically. That being said, I wouldn’t use it in the living room, purely for the sake of the neighbours.


  • solid sound
  • all about that bass
  • you also have the option to connect via cable and USB stick
  • karaoke and instrument features with pitch adjustment
  • option for stereo and multi-room operation
  • long battery life
  • suitable for outdoor use


  • ULT mode doesn’t add much value
  • stereo sound from a single device is very modest
  • potential misuse (affecting neighbours, nature)
  • app (as of 11 April 2024)
Header image: David Lee

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My interest in IT and writing landed me in tech journalism early on (2000). I want to know how we can use technology without being used. Outside of the office, I’m a keen musician who makes up for lacking talent with excessive enthusiasm.

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