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Sony SRS-XB21 review

The pint-sized Sony SRS-XB21 speaker brings the bass

Sony SRS-XB21 speaker
Sony SRS-XB21 speaker
(Image: © Sony)

Our Verdict

Sony remains a powerful brand in the consumer audio arena and, while the sound on the XB21 can easily be overshadowed by its bass-heavy format, its still a well designed speaker with high quality finishes. It certainly gets loud enough and the app-controlled flashing lights and sound profiles are a nice touch to augment the listening experience. It's competitively priced and offers great all-round value for pop and rap enthusiasts.


  • Solid build quality
  • Impressive bass
  • Cool controller app


  • Not audiophile quality
  • Puny light show feature

The Sony SRS-XB21 may be one of the smaller speakers in the Sony range but the sound certainly isn't. This speaker gets plenty loud for its size, especially when you add in the extra bass, but unlike many budget speakers the sound doesn't get more ragged as you crank it up. Rather it seems easily capable of belting out the tunes at full volume without losing is musicality. True to the Sony pedigree it sounds far better than any budget speaker but it is merely on par with the other big brands competing at this price point.

To set it apart Sony has added some extra features. Using the companion app you can adjust the activity of two bright LED lights which dance on the front face of the speaker, and you can configure a range of synth and percussion sounds to fire off when you tap different parts of the speaker body. Also through the app you can adjust the tone and crank up the bass levels. It is this feature more than anything else that is likely to impress the target market: pop music lovers.

Price and availability

Sony's XB21 has been available in South Africa since mid-2019 for R1,500 (£66). It is the entry point to Sony's XB (Extra Bass) range followed by the XB31 (R2,000), sporting bigger drivers and more sophisticated lighting effects, and the XB41 (R3,000) which produces a massive wall of sound with crazy looking backlit drivers and built-in strobe lights.

The biggest competition comes from JBL's Flip 5 , which looks very similar but lacks the extra bass Sony provides. The Ultimate Ears Wonderboom (ZAR1200, £53) is also decent performer. It costs fractionally less than the XB21 but we find the form factor slightly less convenient to handle. Like the Sony both these are water- and dust proof and can be daisy chained together for effect.

Sony's XB range is due to be refreshed in South Africa before the end of 2020.


The fabric covering on the XB21 is popular with many of the Bluetooth speaker brands including JBL and Ultimate Ears. It is surprisingly hardwearing and provides a lot of grip for handling the speaker. It's fully washable too, although not completely impervious to greasy fingers and other culinary coatings. The XB21 is waterproof and comes in 5 colours. 

The irregular tube shape make it easy to wrap you fingers around and helps intuitively figure out which side is front. Unlike some competitors you can't stand the Sony's speaker on end; it must lie horizontal. The control panel is rubberised and sealed, and provides very little tactile feedback, but thanks to the rubber feet underneath you can press firmly without toppling the speaker. 

Sony SRS-XB21

Sony SRS-XB21 speaker (Image credit: Future)

Inside are two full range 42mm drivers and a dedicated woofer which Sony says makes use of material Mica Reinforced Cellular (MRC) to add strength but not weight.

Strongly characteristic of the XB speaker series is the light show built into the speaker body. On the bigger models this comprises a fairly sophisticated seam of LED lights which frame the body of the speaker and can be configured to fire in different patterns, but on the XB21 this is limited to two single LEDs which flash more or less frenetically depending on your settings. Frankly, compared to bigger speakers this is thoroughly underwhelming and Sony might be better off cutting this feature entirely.

Sony SRS-XB21

Sony SRS-XB21 speaker (Image credit: Future)

Performance and features

Tested with both compressed streaming audio and uncompressed high bitrate tracks the sound performance of the XB21 proved to be well above average. In default mode the soundstage was not especially wide although the music was fairly detailed, especially the higher frequencies. Sony's clever LDAC protocol for producing better quality audio streams is also supported here.   

It's certainly not an audiophile class speaker, and it doesn't appear that Sony intended it to be either. There is a lot of definition missing in the mid-range; something that will likely go unnoticed by pop music afficionados. 

XB does stand for Extra Bass and the XB does not disappoint. It produces loads of bass for its size, and it's not the scratchy, woolly distorted bass we associate with stressed smartphone  speakers. This is thunderous rolling bass that can totally eclipse the rest of the music if left unchecked. 

Sony SRS-XB21 speaker

Sony SRS-XB21 speaker (Image credit: Sony)

The Sony Music Centre does an excellent job of unlocking the potential of your speaker. You can set the high, mid and low frequencies and separately set your level of bass boost. The flashing LED lights can also be controlled here, and this is also where you would group and control multiple Sony speakers. 

Along with the puny light show another forgettable feature is what Sony calls the Party Boost. These are sound effects you can fire off by tapping different sides of the speaker. Want to play along adding in some scratching, some synth riffs or some cowbell? You can customise your sound effects in the app. In practice we found these imprecise and deeply dissatisfying. 

Sony SRS-XB21

Sony SRS-XB21 speaker (Image credit: Future)

Buy it if....

You want a small, well-made speaker It's a convenient shape to slip into bags and is small enough to fit easily on car dashboards. It's also built to last and can take some rough treatment.  

You like pop, rap and dance music The promised extra bass is impressive and the weaker mid-range frequencies won't affect you too much. 

Don't buy it if...

You have audiophile pretensions If you're looking for a detailed but balanced sound or you like classical music, delicate vocals and jazz, you might want to look elsewhere.