User Experience

Seen above is the right ear bud of the MOONDROP Sparks installed on an artificial ear mold that is similar enough to my own average-sized ears. I had taken four photos, one for each of the size M ear tips included with the earphones, but soon realized that the fit itself did not look all that different. What's different is the quality of said fit, with the foam tips adhering well to the ear canal, and the longer silicone tip providing a deeper fit. I chose the standard length, average flexing silicone tips that better represent what a stock TWS or IEM tip would be, and those are used in the image above. The fit itself is fine thus, and the ergonomic shape of the shells better contours it in the concha such that the part jutting out at the bottom is directed towards your mouth for the vent/microphone there to pick up your voice. These also weigh ~5 g each, making them low in density and not at all physically fatiguing. Passive isolation is fairly good thus, which helps with the sound quality, too.

Battery life is a key metric for TWS earbuds, and these promise 8 hours of use when fully charged, which typically is a best-case scenario at lower volume and in SBC/AAC mode. I got over 7 hours regularly with aptX and volume set to ~70% on my phone, which was loud enough not to merit going much higher. While not industry leading, it's plenty for most people on a single charge. The real plus point for battery life comes with the included case, which easily provides another six charge cycles, making for a total of ~50 hours depending on your use case. The case single-handedly makes the MOONDROP Sparks a viable option to take on a trip without worrying about battery life. This is why I wanted the case to do more, especially given its relatively large size. The quick charge function is admittedly nice in an emergency, and the fully charged case and earphones combination can be enough for a weekend break without worrying about charging these, which would take ~4 hours for both. MOONDROP does not provide an IPxx rating, which may be a case of lack of testing more than anything else.

Audio Performance

Audio Hardware and Microphones

As is the case with most TWS earphones, MOONDROP uses a single dynamic driver per ear bud, in this case a 6 mm beryllium-coated diaphragm with a polyurathane surround and Japanese Daikoku copper-clad aluminium wire (CCAW) voice coil. The company is also making a big deal about higher efficiency magnets, as neodymium magnets generate higher magnetic flux relative to the average, which should drive the diaphragm back and further faster; and the Be-coating should make for a stiffer diaphragm to reduce inertia further. All this makes for a higher resolution driver which then gets the same MOONDROP virtual diffuse surround field (VDSF) tuning as the target curve.

As mentioned before, the Qualcomm QCC3040 chipset has the ability to provide features MOONDROP did not implement here, but clear voice capture (cVc) remains, which has digital filters better reduce background noise picked up with your voice from the microphones. It makes for a more than passable user experience on a call, be it on the phone or a laptop, but certainly is not the best I have heard from earphones and TWS sets. The touch controls and customization options are also more hit-and-miss in execution—the touch sensor just is not that good. I had double and triple taps ignored enough times to want a setting in the app to customize the delay time between taps, for example. Single taps and longer holds worked much better by comparison.

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 current testing methodology begins with a calibrated IEC711 audio coupler/artificial ear the ear buds can feed into to where there is 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 these TWS earphones connected to the laptop through Bluetooth. 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. I am also using the pinna mold fitted to the audio coupler for a separate test to compare how these fare when installed in an ear and cheek geometry and not just the audio coupler by itself. The raw data is then exported from REW and plotted in OriginPro for an easier comparison.


The IEC711 is such that you can't really compare these results with most other test setups, just within our own library of measurements. 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 MOONDROP Sparks, or at least the useful part of it. The left earbud 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 basically identically throughout the entire 20 Hz to 20 kHz range, and this was the same with a lower degree of smoothing as well. This is of course considering that the IEC711 isn't all that reliable at higher frequencies, but it's not like I heard anything different with these in my ears, either. I will also mention that there was no discernible break-in period or effect, so overall reproducibility and consistency are good since the average response for each channel is also basically the same across the three repeated tests. This continues with the artificial pinna response only having a resonance shift in the treble, and the overall response matching the more ideal fit achieved with the IEC711 coupler. Keep in mind that with TWS earphones, the fit is quite important, as is the connectivity and signal strength from the source.


Speaking of a resonance shift, I try to fit the IEMs and TWS earbuds in such that they have the resonant peak at 8 kHz. However, in this case, that only happened with a looser fit into the coupler, which wasn't representative of how it would really be in an ear canal, either. Seen above are both of those situations, and I am going with the former as the more representative frequency response.


It's finally time to show off what has been in the works for a couple of weeks now, and that is my frequency response measurement database: VSG.squig.link. This came about courtesy Mark from Super* Review on YouTube, who has helped develop an open source project dedicated to getting frequency response measurements of headphones and the likes for all to see and test, so go give him some love and subscribe to his channel if his content also appeals to you. What this setup allows is for users to easily compare my measurements to my preferred target for a better idea of what I personally like, as well as compare to other target curves at the bottom, inspect different segments, normalize based on SPL, or at a chosen frequency, and easily compare other devices to each other.

Adherence to my target does not necessarily mean a product gets a good review, of course. There are several IEMs that have gone in a different manner, yet I appreciate them for what they do. As long as a product is tuned well and meets its expected marketing goals, the target is just a comparison point to understand where things lie. Indeed, the target curves are much simpler approximations of a desired tuning, so the real measurements are better off deviating in the 10–20 kHz region to avoid fatigue. Besides, items such as the technical performance of drivers are not really accounted for by these measurements. What we do see is the MOONDROP Sparks being slightly brighter than I'd like in the upper mids, but it otherwise appeals to my specific tastes a lot.

The MOONDROP Sparks is warm-neutral in its tuning and would benefit from a slightly elevated bass response for most people. Indeed, it falls short of the VDSF target, and I unfortunately am not convinced people looking for a V-shaped tuning will like it at all. The dynamics are somewhat lacking as well, and the 6-mm drivers can only do so much. Those who prioritize vocals will enjoy the Sparks far more though, with MOONDROP giving a similar tuning as with its popular Aria IEMs, which also come in at around the same price point. The Aria is tuned better in the upper mids and highs and has superior technical performance, showcasing the limitations of this TWS platform further.

Instrument separation and male vocals are extremely strong, with detail in the lower mids and mids proper that once again made me compare these to wired IEMs. So while techno music is a no-go, lots of eastern Asian pop with a mix of vocals and instruments do great. This can be extrapolated for the likes of R&B and Jazz, which is further complemented by the intimate soundstage akin to a club in, say, New Orleans. Imaging is so-so, but acceptable within the realm of the soundstage and this being a TWS set with lots of digital filters in the way. The treble response and upper mids will highly depend on your tastes, but I'd still say this is not a strong point, either. It may not be shouty for you in the upper mids, but does get somewhat bloaty to where female vocals feel lost. Classical music also feels somewhat let down by the darkness past 10 kHz, with several instrument resonances lost and some higher frequency strings, cymbals, and triangles not getting their moment to shine. What all this makes for is a specific set of music genres the MOONDROP Sparks is very good at, and I suppose that's better than being alright at everything, as is the case with many other TWS sets today.

It's a shame thus that many of my previous TWS experiences happened before I got serious about reviewing them, and some, such as the Lypertek PurePlay Z3 2.0, were measured differently to where I no longer have the data to add for comparison. I mention that set because it lines up well price-wise, but offers more technological features, including 1:1 communication, wireless charging for the case, etc. It also was tuned well to generally better appeal to others, with a bass hike that wasn't overwhelming by any means but added enough energy and excitement to whole new genres the MOONDROP Sparks can't compete against without EQ. This brings us to the lack of parametric or even customizable EQ of any kind from the first-party app, although it is a problem easily solved by a different app or player on the platform of your choice. Then there are more budget-minded entries, such as the Cleer Roam NC and Tronsmart Apollo series, but I suppose the newer Nekocake is MOONDROP's answer to those.