Sony SRS-XB21 Review - The New Compact Party Speaker

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This year, at CES, Sony announced three updated devices in its popular extra bass lineup, the XB21, XB31 and the XB41.

Finally, these new speakers hit the store and today I will review the most affordable and the smallest one from the three, the Sony SRS-XB21.

The older model, the XB20 was a strong contender in the mini party speaker category with a decent sound and a cool light effect, so I was excited to see if Sony could further improve it.

At the date of this review (28.04.2018), the speaker can be bought for $100 and it is available in four color options: red, blue, white and black.

Sony SRS-XB21 Review Video

The Box, Accessories

The speaker comes with only some papers and a micro USB cable included.


The Design

In terms of size, it has pretty similar dimensions as the former model, which means it is a compact bookshelf speaker what you can easily carry in your beach bag or backpack.

The XB21 got a completely new, fresh look, the metal speaker grille and the hard materials were replaced by a mesh fabric coverage, which makes the speaker much more durable and provides a good grip.

From its look, you can see immediately that it is a born outdoor speaker, what can resist scratches and dents easily similarly to the JBL Flip 4.


The used materials are nice, the speaker is well-built and feels premium in hand.

I think it looks good, I especially liked the turquoise color of my test device.

All the three new Sony speakers follow the same design language which most unique elements are the fabric coating and the transparent plastic strip running around the front and the sides of the speakers.

There are two LED lights built under the strip providing a light effect when the speaker plays music.

On the top, you can find four rubberized buttons: Play, Volume Up/Down, Power, which are not real buttons but only small embossed signs.

I think they are a bit too small, I preferred the full-sized buttons of the former model, what were more convenient to use.


The speaker has a cylindrical shape with a curved bottom and it got four small, rubber lags which help it to stand on flat surfaces.

It works well on hard materials, however, it is not so stable and can easily lose its balance on softer surfaces for example if you are using it on a bed.

Music Control

The Sony XB21 provides a quite powerful music control capability, which means you can pause/play the music, skip a song and jump back to the previous track.

However, it did not get dedicated music control buttons, you have to press twice the Play button to jump to the next track and press it three times to jump back.

There is a microphone built into the speaker, so it can be used as a speakerphone to answer phone calls.

Water Protection

One of the biggest improvement over the previous model that the XB21 is much more durable.

While the older model was only splash-proof, the XB21 got an IPX67 certification, which means it is completely waterproof and can be submerged into 1-meter-deep water for 30 minutes.


In addition, it is protected from dust, so you don’t have to worry if you use it on the beach.

Sony even claims that it is shockproof and it has been drop tested from up to 4 feet as well, so the speaker is really durable, it fits well with an active, outdoor lifestyle.

On top of that, it even floats on the water, so it is ideal for water sports like canoeing, SUP or jet ski.

To ensure the water protection, it has a large waterproof flap on its back covering the ports.


Under the flap, you can find an audio jack input port and a micro USB charging port, so it can be charged with its USB cable or with any standard adapters.

There are three additional buttons situated under the flap: the ‘BATT’ button to check the battery level and to turn on/off the light effect, the ‘WPC’ (Wireless Party Chain) button to connect multiple speakers together and an ‘ADD’ button to connect two SRS-XB21 devices together.

Attachment Option

Although the XB21 is designed to be an outdoor speaker, unfortunately, it did not get any attachment option.

It does not have even a loop or cutout where you could attach a lanyard or carabiner to it.

It’s surprising that Sony omitted this feature since it really limits the portability of the speaker.

If you are lucky, it will fit into the drink holder slot of your bag but otherwise, you do not have any option to attach it to your bike or backpack.

How to Setup

The setup of the XB21 is easy, out of the box it starts in pairing mode, the Power LED is flashing and the device is discoverable, so you can easily find it with your phone or computer.

If you want to pair a second device, you can switch the speaker manually to pairing mode by pressing the Power button till you hear a tone and the button start blinking.

The XB21 is compatible with the Sony’s Music Center mobile app, which provides some handy features.


With it, you can set the different light and sound modes of the speaker and in addition, it has an equalizer.

You can also use the app to easily connect together several speakers for an amplified sound.

Connectivity, Bluetooth range

The XB21 features an audio jack input port so besides Bluetooth it can be also connected via cable.

In my outdoor test, I measured around 90 feet Bluetooth range, which is a good range, likely you will not have any connectivity problem with the speaker.

To make the pairing process easier the XB21 got an NFC chip, what is situated under the ‘N’ sign on the top of the speaker.

This means that NFC enabled devices can be easily paired and connected to the speaker just by touching the devices to it.


Extra Features

Like the other new Sony speakers, the XB21 got some interesting extra features, which make it a great party speaker.

Just as the older model, the XB21 has two LED lights built into the front of the speaker which provide a light effect synced to the beat of the music.

Using the mobile app, you can set the intensity of the lights via three predefined light profiles or you can completely turn them off.

By the older model, the lights were located on the two sides of the speaker but now they are built into the top and the bottom of the front panel.

I preferred the old layout, it looked much better and provided a nicer stereo light effect.

Unfortunately, the lights of the XB21 do not look so cool and vibrant as by the former model

An additional, unique feature is the Party Booster mode, which means that tapping the speaker from five different directions will cause it to play various sounds, so it can be used as an instrument.

The type and volume of the sound effect change depending on which surface you tap and how strongly you tap it.

In the Sony Music Center app, you can even customize this function and you can set different sound effects.

While this feature seems funny and interesting at first, I don’t think that many people will frequently use it in a long term.

Unfortunately, it’s simply not precise enough to be used as a real drum pad or jam with your friends, so don’t expect that you will be able to play any complex beat or rhythm with it.


Battery Life

According to the manufacturer, the battery lasts up to 12 hours and it takes around 4 hours to fully charge it.

In my test when I played various types of songs on the speaker in extra bass mode with off lights, the speaker could play music for 2 hours at the maximum volume level.

After two hours the battery level fell under 20% and the speaker limited the maximum volume to 50%.

Unfortunately, in this case, the speaker does not allow to raise the volume level back to maximum.

When I repeated the same test at 70% volume, I measured 2 hours 40 minutes play time till the speaker set back the volume level to 50% and after that, it could operate for another 2 hours 20 minutes on the limited volume level.

So overall it played for around 5 hours before it turned off.

I think this battery life is quite disappointing and below the average.

Maybe using the speaker at 50% volume without extra bass, it is possible to reach a longer playtime, however, I don’t think that many people will use it in this way.

Regarding the battery, another bummer is that the battery level indicator is not precise.

It happened many times that it indicated that the battery level is around 50% and just after some minutes the speaker started to limit the maximum volume level and the voice prompt asked to charge the device.

Sony SRS-XB21 Sound Test

Checking the specification, in terms of hardware, there is no difference between the XB21 and the older model.

Both have two 1.65” drivers and a passive radiator.

According to the marketing materials, the XB21 got Mica Reinforced Cellular speaker cones, which are rigid and lightweight and provide a better sound quality.

In addition, a new feature is the Live Sound mode which means the speaker can blast music in a wider area creating a three-dimensional experience.

In terms of sound quality, the speaker is crisp and clear, the highs and the vocals sound nice and they are distortion-free.

However, in its sound, mainly the highs dominate while the mids are not so powerful.

Comparing it to the former model it sounds a bit thin.

The XB20 has a fuller, bigger sound with a deeper bass, by some songs the XB21 sounds lifeless.

So unfortunately sound-wise the speaker is not an upgrade, actually, it is slightly a step back compared to the older model.

Sony SRS-XB21 vs Sony SRS-XB20 Sound Test Video

Sony SRS-XB21 vs JBL Flip 4 Sound Test Video

Sony SRS-XB21 Extreme Bass Test


The XB21 could improve in some areas compared to the former model, for example, the water and dust protection and the new durable, sturdy design are really useful features, particularly in outdoor usage.

The NFC chip and the party lights are also nice extra features which are quite uncommon in this category.

However, the XB21 has some disadvantages like the short battery life and it is even not a clear upgrade over the previous model.

Its sound is slightly a step back and I think also the light effect of the XB20 looks much better.

Click here to check the updated price of the Sony SRS-XB21 or to buy the speaker


Completely waterproof and dustproof


Light effect, party booster mode

Good Bluetooth range


A bit tiny sound with weak mids

Short battery life

The battery indicator is not precise

The light effect of the former model was better



One obvious alternative of the speaker is the former model the Sony SRS-XB20.

It is only splash-proof, so did not get dust protection and cannot be submerged into water.

It is mainly made from hard materials and not so durable and portable as the XB21.

However, it has a slightly better sound, a more spectacular light effect and at the date of this review, it is around 30% cheaper.


If the full water protection is an important factor for you then it is worth to check the biggest competitor of the speaker, the JBL Flip 4.

The Flip 4 has a similar design, with full mesh fabric coverage and an IPX7 water protection.

It does not have a light effect and an NFC chip, however, it has a built-in strap and provides a better overall sound with a similar price tag.

Click here to check the full Sony SRS-XB21 vs JBL Flip 4 comparison


Dimensions (W X H X D)

7 5/8 in x 2 7/8 in x 2 5/8 in (193 mm x 72 mm x 65 mm)


1 lb 3 oz (530 g)

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