$10 solar headphones reviewed: Are the Solix SL-510 worth it?

The Solix Solar are very inexpensive wireless earbuds. They come with a solar cell on the charging case. In practice, solar charging does add real value. Unsurprisingly, buyers should not expect particularly strong playback quality for around $10. Bass reproduction is not noteworthy. At the same time, the earbuds are durchaus suitable for playing podcasts. Phone calls can be made via the built-in microphone, and voice intelligibility on the other end is good. Anyone looking for especially inexpensive earbuds that are effectively always supposed to be charged does not really go wrong with the SL-510. For most users, the earbuds should probably be seen more as a backup than as their main headphones.

The Solix SL-510 are inexpensive earbuds that come with a charging case with a solar panel and are available at the European discount retailer Action for the equivalent of $10.

The Solix SL-510 come in blister packaging, which presents the product well but does not seem particularly environmentally friendly. Two unusual details become apparent by the time the package is opened: the two halves of the case are held together by a cable rather than a hinge. When closed, the two parts are held together magnetically. There is also a display. The display shows the charging case’s battery level as a percentage, while the earbuds’ charging status is also indicated. Although this does not necessarily seem to be the intended use, the earbuds can be attached to a backpack with a strap, for example. 

The retail box also includes two additional pairs of ear tips in different sizes, as well as a USB Type-A to USB Type-C cable. Pairing the Solix SL-510 is completely straightforward, but Fast Pair is not supported. Low-loss data transmission via LDAC is also not supported. In this case, however, the hardware would likely be more of a limiting factor than the data transmission anyway. Both earbuds have touch-sensitive areas that can be used to pause playback, for example. Answering and rejecting phone calls is also possible. The touch-sensitive areas respond reliably.

The biggest weakness of the Solix SL-510 is definitely the audio quality. To put it positively at first: Music and podcasts can be played on the SL-510 without immediately noticeable distortion. The sound also does not immediately come across as tinny. However, bass and low-end reproduction is extremely weak, which significantly limits playback quality. The EarFun Air Pro 4 used as a reference easily outperform the Solix SL-510 when playing music. Even with EQs, there is hardly anything more to get out of the Solix SL-510, and they don't sport an ANC feature. 

With the right ear tips, there is a certain amount of purely passive isolation. The fit is good, and the SL-510 did not fall out of the ear. There are no burrs, for example, of the kind I still remember from ultra-cheap headphones imported directly in the mid-2010s. We were able to test solar charging in bright Mediterranean sun and were fairly impressed. In half an hour, the charging case gained a very respectable 5 percent charge. Active solar charging is indicated by a green LED on the front. The earbuds hit the advertised 5 hours of playback time in our test, at least at medium volume, albeit just barely.