To test the S0, I used the IEMs for two weeks as my primary listening device. This meant listening to music, watching videos and playing games on my phone.
Build quality and comfort
As I alluded to on the last page, build quality of the S0 is second to none in this price bracket. I previously used a pair of the Sennheiser CX 300 ii earphones which also cost £35 – making them a perfect comparison. Those Sennheisers are made of plastic and I frequently ran into issues with them breaking. I’ve been relatively rough with the S0 – quickly stuffing them in my jeans’ pocket, for instance, instead of wrapping them up back in their hard case – and I’ve had no issues whatsoever.
In terms of comfort, as with any IEM it is a very subjective experience. Out of the box, the S0 is fitted with medium-size silicon ear tips – the kind I usually like. However, those tips didn’t give me a very good seal and the earphones kept falling out.
The larger silicon tips were also slightly too big for me, which caused some discomfort. In the end, I ended up using the included Comply foam tips, and they proved to be excellent. I got an excellent seal with those tips, and as the foam warms up in your ear, it moulds to the shape of your ear canal which means comfort is excellent.
You do have to be careful with foam tips though, as they aren’t as durable as silicon tips, but after two weeks they still seem in good nick. I can, however, imagine in another couple of weeks that they would need replacing due to the foam disintegrating after repeated use.
Getting down to the sound quality, it is worth making clear that the fit you get with your ear tips of choice can have a significant effect on the overall sound. As mentioned, Brainwavz does included nine pairs of tips right in the box, so there should be something for everyone. I did most of my listening with the Comply foam tips, but I also trialled the large silicon tips for a couple of days.
Now, Brainwavz claims that the S0 offers a balanced, neutral sound with clear separation between the bass, mids and highs. Overall, that is true to an extent, but the S0 definitely leans toward the darker side of the spectrum. This is thanks to a fairly prominent mid-bass which really adds a bit of body to the music. It’s far from overbearing – nothing like Beats headphones – but the bass has definitely been given a bit of emphasis over the mids and certainly the treble.
Mid-range separation from the bass is still pretty good, though, as there isn’t really any bass bleed into the mids. This gives a good amount of clarity to vocalists, although I did occasionally think vocals could sound just a touch distant. For watching videos, though, clarity of speech is very good and I had no issues watching plenty of YouTube with the S0.
Getting to the treble, high-end frequencies do roll off fairly quickly with the S0, contributing to that darker sound signature. This means you don’t get as much detail as you would from something like the RHA MA750 Wireless, so it really depends what kind of sound you prefer. Personally speaking, I found the S0 great for listening to rock, pop and hip-hop as you get a good bass punch without any sharpness from cymbals in the high-end. Acoustic tracks, however, do miss that extra bit of detail that brighter earphones can provide.
Overall, the S0 is definitely a slightly dark IEM, with the overall sound actually reminding me of the legendary Sennheiser HD 650 in terms of its tonality. Personally I’d like a bit more detail in the high-end, but I can easily see the S0 appealing to a wide audience.
Given the S0 comes with an ‘Clearwavz’ mic, with a ‘high precision MEMS (Micro-Electrical-Mechanical System) silicon microphone’, it is only fair we test that out.
To give you an indication of what the mic sounds like, take a listen to the short recording below:
That recording was taken with the S0 directly plugged into the Huawei MateBook X Pro, and honestly it is a bit disappointing. I’m not saying every £35 pair of earphones should come with a super-crisp, high-end mic, but surely it is not unreasonable to expect a bit more clarity. If I was on the phone with someone using the S0, I’d constantly be asking them to repeat things as the sound is just quite muffled.