STEREO GUIDE verdict
As the smallest Bluetooth speaker of its brand, the new JBL Go 4 is hard to beat in terms of mobility. However, this requires compromises in terms of sound, especially in terms of bass, level stability and battery life. However, it can be used very well as a modern FM replacement for listening to web radio or podcasts from a cell phone.
Advantages
- Very compact, lightweight; loop for hanging up
- Robust housing, waterproof and dustproof to IP67
- App with equalizer
- Supports Auracast for party mode and stereo pairing
Disadvantages
- Can't outwit physics - only hints at the bass
- Playtime boost function for runtime extension kills the bass
- Short battery life
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Practice / Connectivity8.8
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Price/Performance9.4
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Sound: naturalness / transparency6.5
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Sound: Bass / Dynamics4
The JBL Go 4 is undisputedly the smallest Bluetooth speaker in the American company’s portfolio. Not only the smallest, but also the cheapest and the lightest. Weighing 190 grams, it even undercuts similarly shaped competitors such as the Tribit Stormbox Micro 2 and its predecessor, the somewhat rounder JBL Go 3.
It is particularly suitable as a mobile speaker for a bike bag or rucksack thanks to its unrestricted outdoor suitability with protection class IP67. With its housing protected on the sides by rubberized plastic and on the front and back by hard-wearing Mash fabric with the small carrying strap, it makes a robust impression. And a stylish one too, as the 7 new colors include a camouflage option in addition to purple, pastel pink, blue, white and red.
The outstanding new feature in the specifications is the battery life, which is said to be 9 hours in Eco mode. A significant improvement on the 5 hours of its predecessor. However, the competition offers even more thanks to heavier batteries, especially as the power-saving mode called “Playtime Boost” radically reduces the bass response. However, charging then takes a full 3 hours, which should be borne in mind when operating away from any power source.

Bass from 190 grams?
The manufacturer also promises improved bass down to 90 Hz with the fourth generation of the JBL Go. That would be astonishing considering the tiny housing and the broadband chassis measuring just 40 millimeters in diameter. An oval passive diaphragm at the bottom helps to ensure that the latter can produce something like bass beats from just 4.2 watts of amplifier power.
Both chassis are located behind the central JBL logo. At least in the high frequencies we expect a small directional effect, so that the JBL Go 4 is best hung at ear level or placed on a table. Thanks to the rubber coating on the underside, it stands quite securely there, and of course you can also lay it on its back.
Operation and functions
In any case, the buttons are all easily accessible. As usual with the compact JBLs, the volume control and play/pause control are grouped together as icons on the top. On/Off and the buttons for Bluetooth pairing and establishing a wireless Auracast connection to other compatible Bluetooth.boxes move to the opposite side to the one with the small carrying strap, under which the USB-C port is located. Incidentally, the latter does not need a rubber lip to be waterproof.
While the appropriately sized buttons on the top are still sufficiently visible even in the black version of the Go 4 despite the lack of contrasting color printing, the three side buttons are barely visible, especially in the color version we reviewed.
The Go 4 only accepts signals via Bluetooth 5.3. As there is also no built-in microphone, phone calls and calling the voice assistant must be made directly on the smartphone.
As an innovation in terms of connectivity, the manufacturer refers to the Auracast compatibility, with which a party mode of several speakers as well as a stereo pair of two JBL Go 4 can be realized.

What the JBL Portable App can do
Both operating modes can be activated with the JBL Portable app for Android or iOS . This also applies to the long run mode, which is called “Playtime Boost” here and, as already mentioned, swaps bass power for battery life – a function that did not convince us in the Clip 5 review. In addition, the Go 4 has a fully-fledged 5-band graphic EQ with sensitive adjustment, although this has certain limits due to the small speaker chassis. More on this in the listening test.



JBL Go 4 sound test – can it really deliver bass?
The bad, but predictable news first: the bass is rather hinted at, especially if you play a track with electronic beats and turn up the volume above 50 percent. Then the protection circuit in the small DSP chip of the JBL Go 4 intervenes and cuts the already not exactly abundant bass in order to protect the driver and avoid clipping. It goes without saying that under these circumstances, there is no point in trying to give the tiny Bluetooth speaker a boost with the equalizer by increasing the bass. This applies at least to the lowest control at 64 Hertz. However, you can improve the sense of punch somewhat with the control at 250 Hz.
To come to an end with the criticism of the bass, which is not to be underestimated for the small dimensions: The Playtime Boost may make the speaker last longer, but you don’t want to hear that. Then it sounds really bass-free and croaky like a can. The same applies if someone should come up with the idea of using the “Vocal” sound preset, which is only useful for audio books, for listening to music.
Always be careful with the volume
Music sounded best with the “JBL Signature Sound” and “Energetic” presets. If you hold back a little with the volume and adjust it to the requirements of the respective recording, the JBL Go 4 has nothing to hide in its size class. However, he can hardly show off. But you can listen to breakfast radio very well in the bathroom.
A comparison of a JBL Go 2 from my personal collection, which is many years old, shows the development the series has undergone over time. Not only does it sound practically completely bass-free. Compared to the 4th Go generation, it also seemed very dull in the treble and gave the timbres of voices and instruments a very artificial flavor. The whole reproduction seemed unclean, strained and tainted by a plastic aftertaste. JBL has really done a great job here, even if the Go 4 leaves a lot to be desired in absolute terms. But it is perfectly suited as a very mobile radio replacement for your pocket – if you play it web radio from your smartphone via an app. The smallest JBL can also be used for listening to audio books. After all, our hearing is particularly sensitive to voices. And here the tiny Bluetooth speaker fulfills at least basic requirements.
Verdict and alternatives to the JBL Go 4
In the flat mini outdoor speaker segment, the JBL has to hold its own against the Tribit Stormbox Micro 2, which has similar specifications, or the slightly more expensive but more powerful JBL Clip 5. Its extremely low weight of less than 200 grams is a kind of unique selling point. On the other hand, the battery life is also slightly below that of its heavier competitors. Above all, however, it keeps a certain respectful distance from the Tribit and the equally mature-sounding bigger brother from JBL, especially in the bass. If the budget and the space in your pocket allow it, then the extra expense is worth it – although the GO 4 has really become a successful Bluetooth speaker for its minimal size, against which the original model in the series sounds almost like an old telephone despite its similar dimensions.
JBL Go 4: Technical data
- Manufacturer’s recommended retail price: 49 euros
- Dimensions (W x H x D): 9.4 x 7.8 x 4.2 cm
- Weight: 190 g
- Battery life up to 9 hours (Eco mode, otherwise maximum 7)
- Special features: waterproof according to protection class IP67, app control, stereo pairing, EQ
- More at: www.jbl.com