First things first—I do not have many IEMs in this price range tested at this time, certainly not ones that are not tuned with accuracy and a neutral response in mind. The Campfire Audio Holocene, a twin release to the Mammoth, is where things can be examined more in that regard. As such, I can't tell you whether the Campfire Audio Mammoth is necessarily better or worse than direct peers it is competing against just yet.

That said, there remain some technical and tuning issues that go beyond just the W-shaped tuning itself, which isn't for everyone necessarily anyway. The second half of that W-shape is in itself more of a cursive U-shape, with bigger dips than what I expected from a custom balanced armature driver. Perhaps it is also the vague marketing on the product page that sets different expectations, and the bloated soundstage is a good example of this. The soundstage is indeed expansive and outstretched, but just like the frozen tundra the Mammoth is drawing inspiration from it is unfortunately barren with a false sense of width that is not being occupied. There was a perceived haze which I did not get much of with the other three reviewed Campfire Audio IEMs, and this especially hurt the resolution in the upper mids and clarity, where female vocals drew the short end of the stick.

There is bass bleed into the lower mids too, but this can be positive depending on your listening preferences. In fact, the entire section dominated by that 10 mm bio-cellulose diaphragm dynamic driver is well-tuned relative to intended goals and the output for many music genres. If the Honeydew was a punch to the head in the sub and mid-bass with resounding EDM thumps you will not forget, the Mammoth allows you to appreciate those more with a sense of space that has tenants inside its imaginary room preparing a nice meal for the festivities after you get back from hunting with (or for?) the Mammoth. Some neighbors from the treble region are also coming over with some sides to add to the party. This also allows the bass drop to be built up nicely by the crescendo of house music and works well with other genres, which got me exploring beyond what I expected going in.

There are enough issues to where I can't outright recommend these, but my lack of experience with other competing solutions does not allow for a negative review either, especially when there are many things the Campfire Audio Mammoth gets right. The tuning may be far from neutral, but my own opinion steers close to it. I can certainly see this appealing to many who thought the Honeydew was too punchy, or simply wanted the quirky fun of the Mammoth with that colorful, unique case as well as the glow-in-the-dark accents. The provided accessories are quite good too, even if you get them with the Honeydew and Satsuma, too. If you do get the Mammoth, do me a favor and play it out for ~35–40 hours before judging it. You don't have to listen to it yourself, but that dynamic driver seems to benefit from some activity. I do wish Campfire Audio would do this for us before placing them in the box, though!