While the original TRUTHEAR x Crinacle ZERO were designed to closely follow the Harman 2019 IEM target curve, this new edition is a deliberate and intentional deviation from this tuning. This new tuning is described as ‘more palatable’ by Crinacle in a video showcasing the ZERO: RED, which in this case translates to a similar sound profile that’s more reined in. The low end is less exaggerated, and there’s more of a high shelf in the treble range. It’s generally more aligned with our target curve than the previous edition, except for the mid-treble, which is more recessed. As a result, kicks are snappier, with more emphasis on attack than release. Basslines still sound present and substantial, but they dominate the mix as they did with the original ZERO. The mid-range is extremely well-balanced, so vocals and lead instruments sound crisp and detailed. The treble range is a little more inconsistent, though, as a balanced low-treble response is juxtaposed against a recessed mid-treble that dulls sibilants somewhat.

There have been accommodations made for those who prefer a more bass-heavy sound profile, too, as these buds come with a 10-ohm adaptor that alters the impedance slightly to add more low-end thump to the sound profile. It’s more of a subtle boost than a drastic change in sound, but it’ll also lower your output level slightly, which you’ll need to adjust for. You can see how this alters the sound profile here.

It’s worth noting that we had some trouble getting a solid fit on our testing head with the right earbud, and as a result, our measurements for the right driver are slightly skewed. We don’t expect this to be an issue that would affect you during everyday use, though.