Fit and Comfort

Seen above are the three types of ear tips that come with the Campfire Audio Mammoth, in size M, installed on the right ear bud and inserted into an artificial ear mold. I have average-sized ears, and the ear mold seen above represents my own experiences well enough as a proxy. Size M silicone tips are my go-to for testing since foam tips are not included by some, although in this case, I would rate the best fit in terms of isolation and comfort to be best with the memory foam tips, followed by the final Type-E tips and then the more generic Campfire Audio silicone tips. The flanges on the latter set are simply too soft to work with the slightly larger form factor compared to the Honeydew/Satsuma, where it was a better fit owing to more room for the flanges to grasp on to. These are relatively average IEMs in size, making for at least 2–3 points of contact with the tragus and anti-tragus when in the ear. There is not much outward pressure to worry about, especially with a good self-supporting seal from the memory foam tips. Each ear bud also weighs ~7.1 g, which is average, so the only thing to consider is the MMCX connector with its 360° rotation, wherein you may have to fiddle around slightly to make sure the cable is oriented to go over the back of the ear.

Audio Performance

Audio Hardware

Given the release timing and some of the marketing talk from the company, there was many a comment on whether the Mammoth used the Honeydew as a base. Looking at just the driver configuration, I can potentially see this train of thought. After all, the Honeydew went with a single dynamic driver, and the Mammoth adds two balanced armature drivers to a single dynamic driver. The mammoth tusk lies in the details, however, with the Honeydew using a full-range tuned liquid crystalline polymer diaphragm dynamic driver and the Mammoth using a custom 10 mm bio-cellulose diaphragm dynamic driver, which on its own has the potential to produce quite a good bass response when handling the low frequencies. There is not much more information on the material and construction of said diaphragm or the magnets driving it, however. This continues with the two balanced armature drivers, with "custom" used to shy away from identifying what is used. All we know is that one of those tackles the mids and the other goes for the highs.

All these are fed to the acoustic chamber that gets the 3D-printed custom treatment, which ultimately means it is designed with the intention of optimal sound output from the drivers to your ears. Driving the hardware is quite easy with a rated impedance of just 8.1 Ω at 1 kHz, no aftermarket amps are required. DACs will always go a decent way in the audio experience, however, and a portable DAC/amp might well be part of your collection if you are considering IEMs and other audio solutions in the $150+ price range. Also, the lack of a 3.5 mm audio jack for most phones these days is another reason to consider a DAC/amp that takes digital input and provides a 3.5 mm jack since you will otherwise have to use an adapter anyway, or even a dedicated DAP. If not on the go, space is less of an issue, but the relatively shorter cable may be a handicap if connecting to a PC as the audio source. Campfire Audio also rates the signal sensitivity at 94 dB and an interesting frequency response of 5 Hz to 20 kHz, but good luck making use of that range!

Frequency Measurement and Listening

I will mention that I have a general preference for a warm neutral signature emphasizing a slightly elevated bass and smooth treble range with detailed mids and good tonal separation. I also generally prefer instrumental music over vocals, with favored genres including jazz and classical music.


Our reproducible testing methodology begins with a calibrated IEC711 audio coupler/artificial ear that IEM buds can feed into enough for decent isolation similar to real ears. The audio coupler feeds into a USB sound card, which in turn goes to a laptop that has ARTA and REW running and the earphones connected to the laptop through the sound card. I begin with an impulse measurement to test for signal fidelity, calibrate the sound card and channel output, account for floor noise, and finally test the frequency response of each channel separately. Octave smoothing is at the 1/6th setting, which nets a good balance of detail and noise not being identified as useful data. Also, the default tuning was used for testing, and no app-based settings were chosen unless specifically mentioned. Each sample of interest is tested thrice with separate mounts to account for any fit issues, and an average is taken of the three individual measurements for statistical accuracy. For IEMs, I am also using the ear mold fitted to the audio coupler for a separate test to compare how the IEMs fare when installed in a pinna geometry and not just the audio coupler by itself. The raw data is then exported from REW and plotted in OriginPro for easier comparison.


The IEC711 is such that you can't really compare these results with most other test setups, especially those using a head and torso simulator (HATS). The raw dB numbers are also quite contingent on the set volume, gain levels, and sensitivity of the system. What is more useful information is how the left and right channels work across the rated frequency response in the Campfire Audio Mammoth, or at least the useful part of it. The left channel was separately tested from the right one, and colored differently for contrast. I did my best to ensure an identical fit for both inside the IEC711 orifice, so note how the two channels are pretty much spot on most of the way through the bass and mids. The right channel measured slightly more elevated in the lows, but within 1 dB to where I didn't really notice this in practice. It is past at ~3 kHz that there is perceived channel imbalance even when listening to them. I will say that the right channel seems more dominant in that the combined effect is closer to its frequency response, but this difference I was perceptive to certainly did not help even so.

I will also mention that the dynamic driver does come into its own after ~40 hours of listening. The frequency response doesn't change, but it has more presence in the sub-bass especially after that point. This is also where I should mention that the Mammoth had consistent hissing when nothing was playing—something I expected from a more sensitive set. Was the ultra-low impedance causing it? I can't be sure since even some higher-end desktop DAC/amps did the same and nothing I have here specializes in low impedance drivers. Any music, or just audio in general, played out of these IEMs got rid of the hiss, but there was a slight haze or veil in effect.

This haze is most perceived in the mids to upper mids transition, a recessed section that is then boosted to account for inner ear resonances. This was the biggest weakness with the Campfire Mammoth for me, with female vocals losing clarity compared to the expectations set forth by Campfire Audio. Here's also where I have to put some blame on the company for being vague on the product page. "Huge sound," "muscular musical definition and epic sonic proportions," and "expansive outstretched sound stage and meaty frequency response" don't really tell me much and leave a lot of room for interpretation in a manner where I feel like I am being asked about my choice of steak instead. Then there is the part about incredible presence, which I concur with, especially once the bio-cellulose diaphragm dynamic drivers open up, and also the bit about the Mammoth making you want to "hunt for new tracks." Seems like this set should have been called Cro-Magnon or Neanderthal instead with all the references to hunting things, such as a woolly Mammoth.

Pedantics aside, it was at this point where I was alerted to Campfire Audio being more specific about its intentions with the Mammoth on other platforms. It is here that the company describes the Mammoth's tuning as more of a W than the V-shape or even L-shaped tuning people were expecting. This is certainly more the case, especially with the right channel measurement above when installed in the ear and cheek simulator setup. In this regard, the Mammoth certainly matches expectations that would have been there from day one had the product page been more focused. Unfortunately, this lack of focus carries over to the Mammoth's tuning. There is certainly plenty of presence, but I don't know what it is targeting. The sub-bass was slightly recessed in my sample even after ensuring as good a fit as possible with the foam tips, and it is the mid-bass where the dynamic driver certainly shows itself. Although not for bassheads, there is plenty of energy here to attract EDM lovers and house music aficionados. In fact, the relatively decent transient response in the upper mids and highs suits these music genres so well that I can see people physically rocking out to these.

Moving from the mid-bass, this is where things can get conflicting. I personally felt the bass bleed into the lower mids, which can be helpful with some cases and listening preferences. Male vocals are very good here, and I can once again see fans of rock, hip hop, and metal music appreciating the Mammoth all the more. This is actually where I had the Mammoth veer me towards music genres other than those I would have otherwise picked. Soul and funk were more obvious a match here knowing this, but K-pop worked well, too. If female vocals would have shined more, some of the more bassy K-pop music groups (Blackpink, for example) would have been quite interesting, too. Instruments get an expansive outlet, but it feels artificial. It's almost like Campfire Audio tried to blow the soundstage balloon past the logical limits to where I am inside a concert hall, but without enough instruments playing to really fill out the space. As mentioned, the aforementioned haze starts to make its own presence felt as we head over to the upper mids, and we then get to the highs where things start out quite well, but then get too dark too quickly for my specific tastes. This results in a lack of hangtime for many string instrument resonances and gets worse with other instruments, including pianos and cymbals. I suspect this last part will not impact most potential customers of the Mammoth though, which doesn't seem to be targeting classical music as much anyway, but I felt you should know about it just in case.

Comparison to other IEMs

Speaking of things getting conflicting, I ran into the issue of being a relative newcomer to the IEM review area in not having good comparison materials here, especially for the price range the Campfire Audio Mammoth operates in. The Mammoth being a set of hybrid IEMs with an elevated bass response, I had to go with one in a lower and another in a higher price bracket for two IEMs of somewhat similar intentions. I say somewhat similar, but they really are not, as clearly seen. The HarmonicDyne P.D.1 is far more V than W-shaped, which it still technically is with a more emphasized bass profile and unfortunately shouty and tinny treble response. I did not get the same itch to try out different music genres or even multiple sources and tips there, so the higher-priced Campfire Audio Mammoth did get that victory. The ThieAudio Monarch is a set of tribrids with a sub-bass boost followed by far more range and neutrality elsewhere, so it's not the best comparison. I had listened to the FiiO FH7 a while back, but it was not under controlled conditions, so I can't draw on those experiences for much of a comparison here.

As such, I am adding a second comparison chart above. This time, it's comparing and contrasting the Campfire Audio Mammoth to the twin-released Holocene as well as the Honeydew many were curious about. Essentially, the question was whether the Mammoth was just a better Honeydew in terms of retaining the punchy bass and V-shaped tuning. We know now that is not the case, with the Mammoth being more balanced. In a sense I fear that is also where the Honeydew does things better in being really good at one thing and providing clarity to customers who know this is for them. The Holocene, which will get its own review, also knows what it wants to be and does it well enough. It's tuned quite differently, and better compared to the Satsuma instead, so the twin releases from Campfire Audio are once again for vastly different product segments.