STEREO GUIDE verdict
The Sony ULT Field 7 scored highly in the review with its powerful bass and pleasant vocal reproduction. This is enough to beat the JBL Boombox 3 in terms of sound and the karaoke function with microphone input is also an argument in favor of Sony.
Advantages
- Deep and powerful bass
- Harmonious mids and highs
- Good app, integrated power supply unit, light effects
- Input for microphone/instruments
Disadvantages
- One would wish for a shoulder strap
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Sound: naturalness / transparency8.4
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Sound: Bass / Dynamics9.4
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Practice / Connectivity9.0
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Price / Performance9.3
When you take the new Sony ULT Field 7 out of its packaging, you get an impression of its claim to be best in class in the “roll-shaped party box” category. The design reminded us of an enlarged version of its predecessor, the Sony SRS-XG500, but it’s clear from the dimensions and specs that the new Sony is looking to shake the might of the JBL Boombox 3 reviewed by STEREO GUIDE last spring.
The ULT Field 7 is less suitable for use as a permanent ghetto blaster on the shoulder or on a well-trained arm. Although its battery life of up to 30 hours is predestined for this, there is no classic handle or shoulder strap. At 51 centimetres, the not exactly short castor is transported on small recesses in the ring-shaped feet, which may remind party professionals of aluminum beer kegs from the catering trade.
At 6.3 kilograms, however, the Sony reel is much easier to lift. However, thanks to water and dust resistance to IP67 plus the robust plastic rings with rubber buffers, there are no restrictions when used in the field. The last question remains: What does the abbreviation ULT in the name mean? This is the name of the bass boost button on the well-marked control panel, which can be pressed repeatedly in two different ways to boost the party beats. So either maximum bass or maximum kick bass for higher maximum volume in the middle and higher pitches.
2-way stereo with square bass drivers
The Sony developers have dispensed with the 3-way technology of the competition for their XL ghetto blaster: The Sony ULT Field 7 is a classic 2-way stereo loudspeaker and only drives two mid-range tweeters and two woofers with a total of 100 watts of impulse power. The latter are equipped with reinforced surrounds and an almost square membrane. The aim is to keep the dimensions of the roll portable while maximizing the membrane surface area. In combination with a deep separation to the two small cone drivers, this should even make a built-in subwoofer superfluous, because the square drivers can perform large strokes with impunity.



To ensure that the bass and level reserves are still worthy of an open-air party, two passive diaphragms with a diameter of around 15 centimeters work in the left and right rounding of the roll. They are illuminated with iridescent, twinkling LED rings to enhance the party feeling. Protruding rings with rubber coating protect the chassis and also act as floor stands and carrying handles. The rubber bumpers on the back of the party speaker are square so that the speaker can also be used lying down.
The two 45-millimeter-diameter cone mid-range tweeters are mounted on the outside of the front baffle and are fed with separate signals for stereo. With a distance of around 40 centimeters between the two, you shouldn’t expect any spatiality miracles. In addition, the left and right channels are only arranged in stereo anyway if the ULT Field 7 is operated horizontally. However, if you want to play back real stereo with two ULT Field 7 speakers paired via Bluetooth, you should operate the two speakers upright like floorstanding speakers in a hi-fi system. This not only sounds great, but also looks better.

Many connection options
The Sony is bucking the trend towards Bluetooth as the only playback standard with a cornucopia of options: In addition to a USB-A input for playback from a memory stick, there is an analog input on the rear as a 3.5 mm stereo jack and an additional 6.35 mm jack input for a microphone or electric guitar. A rotary knob can be used to adjust the level of vocals or instruments independently of the overall volume and an echo effect can be activated at the touch of a button. The Key control is used to adjust the pitch of the rest of the music playback to the live recording in six semitone steps. So karaoke can come!
Bluetooth will probably be the most used input option. Here the Sony shines with version 5.2 and the codecs AAC, SBC and LDAC. The latter is a Sony proprietary development that enables better sound quality compared to standard Bluetooth codecs. Some will miss codecs from the aptX family, but for a portable one-box system, the codecs shouldn’t be that important. LDAC has also been integrated into the operating system since Android 8.0 (Oreo), which means that many modern Android devices support the codec. Two Sony ULT Field 7s can be linked to form a fully-fledged stereo set, or several Sony Bluetooth speakers can be networked to form a party chain.
The ULT Field 7 can be charged using the mains cable supplied and a socket. The power supply unit is conveniently built in. The 30 hours of battery life is achieved with ULT Boost activated at just over 30 percent of the maximum volume. With the backlight activated, the runtime is still reduced to a decent 25 hours. At the maximum volume of all power guzzlers, however, it only takes 3 hours. For parties with a full light show, a power socket should therefore be nearby if possible. If you are looking for maximum battery life, you can activate an energy-saving function in the app that reduces the bass somewhat. However, with the powerful bass foundation of the Sony ULT Field 7, there is still enough punch left over for cultivated background sound.









App with many possibilities
The Sony Music Center app for Android and iOS offers a customizable graphic equalizer and the aforementioned “Stamina” function. This function activates an eco mode that extends the battery life, but at the expense of the maximum volume level and bass range. In contrast to ULT mode, which emphasizes deep bass, the Stamina function reduces the fullness of the sound. With very small Bluetooth speakers such as JBL’s new Go 4 and Clip 5, which also have a power-saving mode, the sound is thin and sharp. Sony’s Stamina function, on the other hand, maintains a sufficiently rich sound – unless you prefer strong bass beats. Sony has also given the ULT Field 7 a battery care function that only charges the battery to around 90 percent to increase its service life.
The app also offers stereo pairing for two identical speakers or a party mode with several speakers in synchronous operation for higher sound levels. There are also sound presets for stronger low bass (“ULT1”) and maximum volume levels (“ULT2”) as well as a graphic equalizer for individual sound adjustment. The switchable sound field optimization automatically detects the noise level around the speaker to automatically adjust the sound.
For experienced DJs, two sound effects are also available in the Sony Music Center app: “Isolator” and “Flanger” can be infinitely adjusted in intensity using virtual sliders to create your own sound.


This is what the big Sony tube sounds like
While the Boombox 3 from JBL is very responsive and, depending on the recording and playback level, sometimes sounds quite sharp in the treble, the Sony ULT Field 7 sounds very powerful and earthy. If you press the ULT button once, you get an extra portion of depth and richness. Pressing twice emphasizes the upper bass and provides a feeling of fat punch with electronic beats for the dance floor. As far as the reproduction of vocals or guitars is concerned, Sony relies on a rather warm, homogeneous tuning without harsh tones, as with the small ULT Field 1, which was recently subjected to a review. The tuning makes the Sony speaker seem powerful and suggests that hi-fi reviewers call it a bass monster. However, the Boombox 3 achieves a certain groove thanks to the emphasis on the upper bass and the enormous liveliness in the treble, which goes straight to your feet when dancing.
Compared to its direct predecessor, the Sony SRS-XG500, which with its handle is more visually oriented towards the top dog from JBL, the ULT Field 7 is much more appealing and more responsive both in terms of bass and openness in the treble. Sony manages the balancing act between fat party beats and a sound tuning that also satisfies hi-fi aficionados with acoustic drums.
Verdict and alternatives to the Sony ULT Field 7
The Sony ULT Field 7 is based on the concept of the JBL Boombox 3, which has matured over the years. JBL’s competitor is already very strong in terms of level. However, it doesn’t have any real low bass and also comes across as a little harsh in the treble. The Sony Bluetooth speaker, on the other hand, appears more powerful and slightly less responsive in the mid-high range. It has the more natural tuning, but in addition to the lower list price, it has a decisive advantage in terms of connectivity for party people. JBL only offers an input for microphones, musical instruments or lighting effects on the larger party speakers, such as the Partybox 110, which we covered in a review last year.
The comparison between the Sony ULT 7 and the JBL Boombox is therefore quite clearly in favor of the Japanese manufacturer’s cheaper Bluetooth speaker, except for level stability and transportability.
Technical specifications: Sony ULT Field 7
- Manufacturer’s suggested retail price: 400 euros
- Dimensions (W x H x D): 51 x 22.5 x 22.2 cm
- Weight: 6,3 kg
- Battery life up to 30 hours
- Special features: waterproof and dustproof according to protection class IP67, analog inputs (line, microphone / instrument), stereo pairing, party mode, app control. LED illuminated rings