Crystalsound intends to solve the weak point of Bluetooth speakers, namely the narrowness of their sound field. To achieve this, the Infinity is divided into two small True Wireless speakers, which can be spaced as desired and up to several meters apart. An attractive concept, which is however accompanied by some counterparties.

Based in Spain, the Crystalsound brand develops earphones, headphones, Bluetooth speakers and even connected watches and bracelets. In its range, the Infinity speaker is certainly the one with the most attractive concept, since it can be divided into two mini speakers for true True Wireless stereo listening. The principle is the same as that of TWS Bluetooth headphones: each mini-speaker has its amplifier (10 W) and its battery (1500 maH).
Crystalsound InfinityTechnical sheet

This test was carried out with a loudspeaker lent by the manufacturer.
Crystalsound InfinityDesign
Crystalsound did not play the cards of fantasy and refinement to design the Infinity. The enclosure has a sober look, stripped of any aesthetic artifice. Despite a certain compactness, the enclosure seems massive: a paradox which is certainly due to the absence of any logo or button on three of its four sides, covered with a very fine mesh fabric.

Strangely, the front face does not house any loudspeaker and therefore does not emit any sound. These are the side faces of the enclosure which each house a transducer, for lateral diffusion of the sound. The rear panel incorporates the speaker control buttons, which boil down to volume control and power on. As the enclosure can be divided into two parts, the control buttons are present on each. Ditto for the micro-USB charging sockets.

The ends of the enclosure house the passive radiators, made of glossy plastic and flanked by the brand logo. Their suspensions hide LEDs that light up white according to the music played.
The left part of the speaker is equipped with a small silicone loop for hanging the speaker, while the opposite part has a stand for vertical positioning. The Crystalsound Infinity is IPX7 certified and therefore resistant to water splashes as well as immersion. When the enclosure is divided into two parts (by simple unscrewing movement), each module has an inclined base with non-slip coating.

Finally, the perceived quality is not exceptional. Moreover, one of the passive radiators of our test copy was a little off axis.
Crystalsound InfinityUse and application
Let’s not beat around the bush, the ergonomics of this speaker is far below competing devices. Its grip is not very pleasant, partly because the speaker is heavy for its size (860 grams) and its coating is not very adherent. The carrying strap is far too small to hope to pass more than a finger through it, which combined with the 860 g of the speaker, makes it difficult to transport or hang. Disappointment also with the ambient lighting, which is limited to white, and again on the condition of listening loudly. Otherwise, the LEDs do not light up. The separation and stowage of the two parts of the enclosure do not however pose any difficulty.

The volume management is quite fine, with multiple increments to precisely adjust the volume. Unfortunately, the volume cannot be zeroed with an iPhone and must be adjusted on both the smartphone and the speaker.
The Bluetooth connection is stable up to 10 meters away and even through a floor. However, clipping sometimes occurs, probably due to the TWS transmission between the two speakers. In short, the music sometimes cuts out for a few seconds.
No mobile application is offered to manage the speaker, which prevents the user from deactivating, for example, the start and stop sounds (guitar chord) or modifying the sound signature with an equalizer.
Crystalsound InfinityAudio
The Crystalsound Infinity loudspeaker is equipped with a pair of broadband loudspeakers (approximately 5 cm in diameter), each assisted by a passive radiator (also 5 cm in diameter). This assembly gives the active loudspeakers better efficiency at low frequencies and less excursion of their membrane, the lowest frequencies being reproduced only by the passive radiators.

Unlike other Bluetooth speakers using this acoustic assembly, the active speakers here do not share the same load volume (of air), since the speaker is in practice composed of two separate mini-speakers. Each has its own 10 W amplifier and battery.
Test conditions
I listened to the Crystalsound Infinity speaker paired with an iPhone 13 Pro Max, Xiaomi Mi 11 Lite 5G, and MacBook Air M1, from Apple Music.
Signature sound
The Crystalsound Infinity speaker suffers from a lack of tonal balance, which sees the mids and highs dominate the frequency response. The bass is sorely lacking in volume and, unfortunately, also in extension. This loudspeaker is thus not generous in its restitution, but shows a certain softness at the top of the spectrum. Only positive point, its tonal signature does not vary according to the volume, although beyond 50% of the volume the sound suffers from distortion. Clearly, this speaker is not designed for playing loud.
- Bass: from the top bass and nothing else, the extension is very limited, probably because of the low load volume or the very rigid suspensions of the passive radiators
- Medium: balanced and soft
- Treble: well placed, but not very dynamic
Dynamic behavior and soundstage
The soundstage is the strong point of the Crystalsound Infinity. As soon as it doubles, the mini-speakers can be positioned freely and we obtain a sound stage of quite exceptional magnitude. Plus, the investment possibilities are endless.

On the other hand, when the speaker is in monobloc mode, the sound is not convincing, because each mini-speaker diffuses in a direction opposite to the other. In fact, we always listen to half of the sound message and, in the absence of mono mode, this poses a problem with certain titles with very marked stereo. Take the repertoire of the Beatles, the Rolling Stones or the Doors in their early days, made up of overused stereo titles (voice on one side, instruments on the other): well, these titles are difficult to listen to when the loudspeaker is not divided.
If the vast soundstage is the Crystalsound Infinity’s asset, its dynamic behavior is quite nondescript. The transducers used lack juice and struggle to produce a catchy sound. From bass to treble, it’s soft on the knee and we are far from the dynamic behavior of the references in the category (JBL Flip 6 or Huawei SoundJoy).
Outdoor performances
Unsurprisingly, the weakness of the speaker in the low frequencies makes it difficult to use outdoors, where it struggles to produce anything other than midrange and treble.
Crystalsound InfinityMicrophone
The Crystalsound Infinity offers a hands-free function for making phone calls. The microphone is installed in one of the mini-speakers and it is also only this one that broadcasts the voice of the interlocutor. The capture of the voice lacks sensitivity and you have to approach about ten centimeters from the speaker to be heard. What’s more, the sound is muffled and therefore not very intelligible. It is therefore better to use your phone in a noisy setting, even if the presence of a microphone is always good to take.
Crystalsound InfinityAutonomy
The manufacturer announces up to 7 hours of autonomy, without however specifying at what volume of listening. At 50% iPhone volume (and maximum speaker volume), the Infinity lasted only 5 hours in this test. This is quite a bit and much less than what the competition offers.

Finally, the charge is slow – 5 V / 0.8 A, or 4 Watts only – and since two batteries are present, it is necessary to use two USB sockets. Allow a good two hours to refuel.
Crystalsound InfinityPrice and release date
The Crystalsound Infinity speaker is available in black or red, at a price of €79.99 including tax. At this price, it competes with the small Sony SRS-XB23, which is more ergonomic and musical.