Fosi Audio C3 Review: Is StepSense Worth The Hype?
Greetings mate and Welcome aboard! Stuart Charles here, HomeStudioBasics.com helping YOU make sound decisions, so…
Fosi Audio’s C3 takes a different approach to gaming audio by analyzing game sounds in real time, purportedly making the experience better by identifying and prioritizing critical sounds so you can react faster.
By dynamically enhancing footsteps and other important environmental cues, the C3 aims to give you a leg up on the competition, providing sweaty try-hards and casual homies alike the chance to both improve their game and enjoy the nuance of it.
Fortunately, the C3 doesn’t apply this to ambient sounds or gunfire; it highlights only what matters: footsteps, reloads, and other environmental cues.
But does it actually work? Let’s take a gander.
Build & Features
Build quality is solid.
The unit is a compact, boxy-looking square shape with built-in rubber pads on the bottom, and it’s small enough to fit into most spaces without an issue.
The front contains the headphone output and mic input, and on the back, there’s an optical input, a coaxial input, a pair of RCA outputs, a USB-C power slot, and a noise reduction switch.
Enabling this feature helps reduce unwanted background noise picked up by the microphone, improving voice clarity during calls and in-game communication.
The top panel houses an orange power button, mic mute button, UAC (1.0 & 2.0), Effect button (FPS,7.1), volume and mic sliders.
These sliders feel nice to adjust and add an intuitive element to the DAC that I haven’t seen in other products.
To cycle through inputs, just short-press the orange power button.
Fortunately, the C3 works nicely with my PS4 as a plug-and-play USB unit. That said, PC users will get the most out of it thanks to the companion software, which unlocks additional features like the Parametric EQ.
To access this software, click here and follow the prompts.
One thing to keep in mind is your browser. Firefox users like me will need to use something else (Edge or Chrome, for instance) to access the app. Not a huge deal, but slightly annoying.
Fortunately, that minor annoyance dissipates completely once you open the app. It’s very clean, intuitive, and useful, providing dedicated game presets while also allowing you to make your own.
Right now, Fosi has dedicated presets for Counter-Strike 2, PUBG: BATTLEGROUNDS, Delta Force, and Valorant. Additional ones include R&B, 3A Game, and FPS, followed by the 3 custom slots. Pretty nifty.
While the C3 functions as a DAC/Amp perfectly well with virtually any game, its StepSense technology is currently optimised for a handful of supported FPS titles just mentioned.
If you’re playing something outside of that list, you’ll still benefit from the unit’s performance, EQ, and other processing features, but the footstep enhancement may not have the same effect.
Luckily for you, Fosi says more games will be supported over time. As the manual points out, “More games will be supported through ongoing optimization.”
In the meantime, all of the ones supported are free, and 3 of them can be downloaded on Steam.
Speaking of downloading games, let’s see if the StepSense feature works as intended…
Gaming
Today I’ll be gaming on Counter-Strike 2, one of the most iconic competitive FPS games ever made, and a title officially supported by the StepSense feature.
This game was obviously meant to be played with your mouse, but you can actually use a PS3 controller and it still works.
That said, I tested the C3 with both a controller and a mouse, and after toggling StepSense on and off throughout multiple matches, I do hear a subtle but noticeable difference.
Obviously, footsteps are enhanced, but you’ll also notice that the environment, sounds, general ambience, etc. receive a bit of a boost in resolution, and Soundstage is also better.
In other words, it feels a little more like a 3D environment with StepSense on, but micro detail and overall clarity also improve.
Further, the audio is crisp, imaging is precise, and directional cues are excellent, making it easy to pinpoint where enemies are coming from a little better than having the feature turned off.
Having never played this game before, my first impression is that I’m terrible at it (not surprising), but also how much it reminds me of an old favorite, Call of Duty 4: Modern Warfare, a game I was really good at back in the day.
The gameplay here is more methodical, but its crisp presentation, grounded environments, and heavy emphasis on positional audio gave me a similar feeling of heavy nostalgia.
It should be noted that different UAC modes yield different options.
Under UAC 1.0, the software provides StepSense, while 2.0 replaces it with Spatial Audio, an FPS preset, and a Parametric EQ. Since these features rely on the companion app, you’ll only be able to use them on desktop.
Music
Switching over to music, there’s not a whole lot to report, and that’s a good thing.
You’re getting a clean conversion, and the music sounds crisp and competent, letting the headphones and source do all of the heavy lifting.
I spent time listening to a variety of tracks and never felt like anything was missing. Detail retrieval is solid, imaging remains precise, and the presentation is enjoyable, even if it doesn’t distinguish itself from other fine DAC/Amp combos in this price range.
Ultimately, the C3’s biggest strength isn’t trying to reinvent the wheel; it’s providing a capable all-around DAC that can easily work for both gaming and listening to music.
Power
I tested the C3 with the Beyerdynamic DT 900 Pro X and AKG K702, the former of which isn’t hard to drive, and the latter, which is certainly much less efficient at around 91dB/mW.
The great news is that I barely have to turn the volume up on the C3, as it drives the headphones nicely with plenty of headroom left to spare.
More importantly, there’s no hiss, crackling, or distortion at higher volumes, and unless you’re pairing this device with super power-hungry cans, I don’t see power output being a concern for most folks.
Other Things To Know
If you run into a compatibility mode issue, just go here, follow the steps, and you should be good to go.
Final Verdict
Fosi Audio’s C3 is a gaming DAC/Amp that gets a lot right, delivering solid performance, a good build, a few different ways to connect, and plenty of power for most headphones.
The software app is a nice add-on, providing more flexibility than I was anticipating. After updating the firmware, I’m able to use the device in UAC 1.0 or 2.0 and take advantage of all the features. That said, you can only use StepSense in UAC 1.0. In 2.0, it gets replaced with “Spatial Audio,” an FPS preset, and Parametric EQ.
Just keep in mind that these software-based features are only available on desktop.
Fortunately, the product’s flagship feature works as intended, helping to enhance footsteps but also give the environment a more realistic feeling.
Overall performance is good; it drives headphones pretty easily, and it provides an enjoyable experience whether you’re gaming or listening to music.
Pricing/Box/Specs
Fosi Audio C3
User Manual
USB-A to USB-C Cable
Mic Splitter
Specifications
- DAC/Amp Chipset: XMOS XU316 + Cirrus Logic CS43131 + dual TPA6120
- Supported Headphone Impedance: 16–300Ω
- UAC 2.0: PCM up to 32-bit/384kHz; DSD256
- UAC 1.0: PCM up to 16-bit/48kHz
- Optical: PCM up to 24-bit/192kHz
- Coaxial: PCM up to 24-bit/192kHz
- Inputs: USB-C, Optical, Coaxial, 3.5mm Microphone
- Outputs: 3.5mm Headphone, RCA
- Headphone Output Power: ≥320mW + 320mW @ 32Ω
- Headphone SNR: 123dB (A-weighted)
- Headphone THD+N: 0.0004% (A-weighted)
- Headphone Dynamic Range: 123dB
- Headphone Noise Floor: ≤3µV (A-weighted)
- Frequency Response: 20Hz–20kHz (±0.06dB)
- RCA Output: ≥2Vrms
- RCA SNR: 124dB (A-weighted)
- RCA THD+N: 0.0005% (A-weighted)
- RCA Dynamic Range: 124dB
- Input Voltage: DC 5V
- StepSense Footstep Enhancement: 3–9dB boost
- StepSense Latency: 10ms
- AI Noise Cancellation: Up to 40dB background-noise reduction
- Firmware Updates: USB-C online update
- Platform Compatibility: PC, PS5, Nintendo Switch, headphones/headsets, and desktop speakers
