The more great earphones I have the pleasure to use, the harder I find them to distinguish from each other. The RX8 by RevoNext are no different. Great-sounding, decently-priced earphones. Although the build quality of the housings isn't as great as the brand's more expensive offerings. They are quite similar to some of KZ's models in that regard, like ED16. However, the cable is actually better, and the sound quality is just marginally below the significantly pricier QT2, due to less micro-detail that is exclusive to RevoNext's higher-budget models.
That being said, if you try to compare them against QT2, you'd be hard pressed to tell which one is "better". They are both exceptionally good, but you can get similar-sounding earphones by KZ at a much lower price, KZ ES3 and KZ ZST being the most comparable examples, although the RX8 are far more comfortable and have the better cable of the bunch.
RevoNext chose a safe shape for RX8's housings, so they fit very nicely into the ears, stay there firmly even with the included tips, and stay flush enough to be able to put your head on a pillow while using them. Common, yet effective design, that leaves no room for risks.
Lows / Bass
The bass is very balanced and controlled, but it's also underwhelming and overrun by the super-bright highs. It's more than enough for contemporary vocal-oriented music, but for electronic music this is just not enough. Depth-wise, they are similar to ES3 but slightly shallower. Compared to QT2, it seems as QT2's bass is cleaner and more extended, while RX8's is more punchy and aggressive, more like typical V-shaped sound signature.
Mids / Vocals
The mids are highly impressive, and actually very similar to ES3, to the point where it's really hard to tell them apart. The detail is quite extraordinary, but the QT2 manages to pinpoint microdetail quite better than RX8. Along with the great vocal clarity, comes some unsatisfying pierce that afflicts vocals, especially female vocals, and high-pitched instruments.
Highs / Treble
They highs are very sharp and crisp. They are also quite piercing, almost like the ES3, but not as sharp. Depending on how sensitive your hearing is, you might feel discomfort and fatigue after using these earphones for a while, especially if you're listening on medium/high volumes. Superb calrity and tonally accurate, except that the treble is very bright, far brighter than what I would consider enjoyable.