Fit and Comfort

There are subtle fit differences between the different ear tips of the same size. It's hard to see on the camera front-on, however, so I am only showing an example with the size M "balanced" silicone tip on the right ear bud and inserted into an artificial ear mold. I have average-sized ears, and the ear mold above represents my own experiences well enough as a proxy. This particular combination is also what I used for my listening and measurements, and it did seem more balanced than the other single-flanged tips while also providing a good seal without being too intrusive as with the double-flanged tips. Foam tips, while more likely to provide a good seal, may damped the sound signature in the higher frequencies. The size of these IEMs is on the smaller side of average, and the circular form factor also makes it more like your average TWS earphones when it comes to the fit and installation. There are still multiple points of contact in the concha of the average human ear, but it's the relatively light ~6 g and form factor of each that make these comfortable. The cable also provides an additional point of support at the top and around the back, with the freely rotating MMCX connectors on the angled housing not forcing the fit dependency of the IEMs on cable positioning. These are otherwise closed IEMs with good passive isolation that can look like some form of ear jewelry if not expecting IEMs.

Audio Performance

Audio Hardware

As part of FiiO's FA IEM series, the FA7s only uses balanced armature drivers across the entire rated 10 Hz to 40 kHz range. In this case, we get a total of six BA drivers split into three sets of two each with a triple electronic and structural crossover to hit a 1:1:1 balance between the lows, mids, and highs. The lower frequencies are handled by the Knowles HODVTEC-31618-000 dual woofer, mids by two custom BA drivers made specifically for FiiO, and treble range by dual Knowles RAD-33518 drivers—one of which we saw in the FiiO FHE:Eclipse. Notice the individual driver responses and how the crossover system brings the three sets together for the resulting factory response curve, which is the target my set should aim to hit, too. All this makes for a set of IEMs that is quite easy to drive with an average rated impedance of 18 Ω combined with a relatively higher sensitivity of 111 dB/mW. Purely by numbers, it's easily handled by even a basic USB Type-C dongle, let alone mobile devices, such as one of the portable Bluetooth options we have covered before to easily use it with a variety of different sources. The lack of a 3.5 mm audio jack for most phones these days is another reason to consider a DAC/amp or even DAP for portable use. If not on the go, space is less of an issue, but the relatively short cable might still be a potential handicap if connecting to a PC as the audio source.

Frequency Measurement and Listening

I will mention that I have a general preference for a warm-neutral signature with a slightly elevated bass, smooth treble range, 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 IEMs can feed into enough for decent isolation. 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 1/12th 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 appropriate ear mold fitted to the audio coupler for a separate test to compare how the IEMs fare when installed in a pinna geometry instead of just the audio coupler. 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 of the FiiO FA7s. 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 practically identical to each other across the entire useful 20 Hz to 20 kHz range. I had to listen for channel imbalance in the 5–7 kHz region to notice it, which was only after initial measurements were taken. Ignorance was otherwise bliss! Measurements taken after 30 hours of testing, which included these playing a mix of various songs as well as white or pink noise and sine sweeps showed no difference. There was no perceived burn-in effect thus, and none was measurable, either. The response with the anthropomorphic pinna in place matches the ideal scenario in the coupler very well, which is also an indicator of how good the seal was when installed in the artificial ear.


This is the average frequency response for both channels of the FiiO FA7s plotted against my personal target taken from VSG.squig.link, which gives you an idea of my personal preferences to better correlate any possible biases. The tuning of a set of headphones or earphones does not have to match my target as long as it is tuned with some direction, makes sense, and is executed well. After all, no one set will appeal to everyone, and having different options is what makes this hobby so interesting and hard to quantify. FiiO says the FA7S tuning style is "balanced, with strong sound reproduction, high resolution, good treble extension, fine and transparent," with more marketing talk in the form of a moderate high-density bass, stronger resolution, "poisonous" vocals—whatever that means—and an overall transparent sound signature.

I am not sure how to describe the tuning of the FiiO FA7s, but it does remind me of a spade. I am not a fan of the set for a few different reasons, and if this is supposed to be an improvement over the older FA7, it must mostly be in the treble response where the FA7s has more extension. The first part of the tuning, approached from the lower frequencies up, is one I have seen from a few different companies, and it almost never worked out well in my opinion. There's certainly bass extension, with a ~6 dB rise from the lowest point in the mids at 1 kHz that continues all the way down to 10 Hz if you were to take FiiO's word. In practice, however, the use of balanced armature woofers makes the bass elevation less impactful and closer to my own target. With a thin dynamic range then, I will give FiiO credit for working on the Knowles drivers to get plenty of detail that helps with acoustic guitar leading tones, even if the trailing edges get muddled up. These do respond well to EQ though, so if you want more volume in the lower frequencies have at it. Just realize that it's not going to improve technicalities much.

It's what happens next that is my biggest issue, with the custom FiiO BA drivers seemingly tuned for "poisonous vocals." If that means making me not want to listen to vocals through this set, I suppose it is job well done! The mid-bass is bloaty and bleeds into the lower mids with too much energy for male vocals to stand out as anything but thick, and trying this set with classic rock music showcases this weakness quite easily. I can see a market for the warm and "full-blooded" tuning, but it's certainly going to be an acquired taste. Instrument separation also takes a hit, which results in imaging that goes from being precise in a ~20°cone around the ears to hazy on either side before reconciling to an extent in the center. Combined with the smaller soundstage for even IEMs, it is a small room that is playing music from sources you are not easily identifying the location of. It's a distraction from the fun you want to have here, which is a shame because certain tracks worked quite well. Then there's the point where the upper mids seem neglected, with no practical pinna gain accounted for. While some male vocals came off boomy, female vocals were barely present and hollow. I had to EQ a lot in the mids and found there wasn't much room to get a pinna gain to my liking—perhaps a driver limitation?

The upper mids giving way to the treble drivers is startling during a sine sweep, especially as you hear sudden brightness and presence that was lacking for earlier. But in practice, it does not come off so jarring, and I will go ahead and say the treble response might well be the best thing about the FiiO FA7s. It's engaging without being fatiguing, and there's enough range and detail for orchestral music to play well. Some second-order harmonics add charm that otherwise feels lacking elsewhere, although it does come at the expense of some string instruments, cymbals, triangles, and higher-pitched piano keys not getting their due. I also know now which set to show others when they want to know what BA timbre sounds like, with guitar strings coming off slightly plasticky and the saxophone in particular not sounding as I expect it to.

Comparisons

Seen here is the FiiO FA7s compared to a few other all-BA sets I have covered thus far, including the Etymotic EVO with three BA drivers, Campfire Audio Holocene with another three BA configuration, and then quad-BA SeeAudio Bravery. There's also the ThieAudio V16 Divinity with a whopping 16 BA drivers and 64 Audio U18t with 18 BA drivers, but both are on a whole different level, including price-wise. You might think that the FiiO FA7s with its six BA drivers costs more than the other three, but this is where FiiO's value-for-money mindset combined with the use of four off-the-shelf drivers comes in handy since the Etymotic and Campfire Audio offerings cost more. I'd take the FA7s over the Holocene, with tuning mostly a wash and technical performance better with the Holocene, but the FA7s does better with fit, comfort, the provided cable, and of course all the other accessories you get at a significantly lower price. The Etymotic EVO is a niche set owing to its predominantly neutral sound signature and much deeper fit, and I would still take the EVO over the FA7s by a whisker because the former executes its mission much better. It's the SeeAudio Bravery that is the real winner by costing the least of the lot, going with a deliberately outsourced tuning from the masses, having arguably class-leading technical performance for an all-BA set, and getting all the basics right.


This time around, I wanted to focus more on IEMs that are in a closer price range to the FiiO FA7s regardless of the driver configuration, which includes the ill-fated HarmonicDyne P.D.1 that makes the FA7s look like Michelangelo carved it out of stainless steel and unworthy of being in the same conversation as any of the others. Those incidentally are the Audio Hekili and XENNS Mangird Tea 2. Both are yet to be covered here and employ more traditional hybrid driver configurations. I'd go with either of those over the FA7s, with easy wins when it comes to competent tuning, excellent dynamics, and little reason to EQ making them great plug-and-play sets. Where the FiiO offering bests them is in fit with smaller ears, a larger distribution network that arguably means it could be the only option available for you, and better customer service on top of the richer accessories.