> ## Content Index > Fetch the complete content index at: https://www.soundpathlab.com/llms.txt > Use this file to discover other available public pages before exploring further. # Fosi S3 vs WiiM Pro Plus: Which $250 Streamer Should You Buy? - URL: https://www.soundpathlab.com/fosi-s3-vs-wiim-pro-plus/ - Published: 2026-08-16T23:27:21.000Z - Updated: 2026-09-14T01:22:57.000Z - Description: At $259.99 and $249, Fosi S3 and WiiM Pro Plus now compete directly. Compare XLR, HDMI eARC, Roon, apps, DSP, measurements and limitations. - Author: SoundPath Lab - Tags: Comparisons, Buying Guides, Music Streamers, WiiM, #Fosi Audio At **$259.99 for the Fosi S3** and **$249 for the WiiM Pro Plus**, these two network streamers now compete at effectively the same price. The old argument that WiiM was the substantially cheaper option no longer applies. Promotions can still reverse which one costs less on a given day, but at normal current pricing the decision should be based on system fit—not an $11 difference. The short answer is straightforward: **WiiM Pro Plus is the safer all-round recommendation for most listeners. Fosi S3 is the more specialized choice for systems that genuinely need XLR balanced output, HDMI eARC or a wired subwoofer output.** Editorial status: evidence-based product comparison using manufacturer specifications, current software documentation, independent measurements and documented owner reports. SoundPath Lab has not performed a controlled hands-on A/B listening test of these two units. ## Quick decision - **Choose WiiM Pro Plus** for the stronger app, Roon Ready certification, room correction, mature EQ, better-documented analogue input, multi-room features and long-term software confidence. - **Choose Fosi S3** for 4Vrms XLR output, HDMI eARC, a physical subwoofer output and a larger rotary volume control. - **Neither is ideal** if you need USB audio, USB-drive playback, a headphone output, a phono stage or complete wired 2.1 bass management. ## Specifications and feature comparison | Feature | Fosi S3 | WiiM Pro Plus | | ------------------------------- | -------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- | | Current U.S. price reference | **$259.99** direct from Fosi | **$249** current retail | | DAC | AKM AK4493SEQ | AKM AK4493SEQ | | Main analogue output | RCA 2Vrms; **XLR 4Vrms** | RCA approximately 2Vrms | | Analogue input | RCA; digitized internally at **48kHz** in independent testing | RCA; TI PCM1861 ADC, up to **24-bit/192kHz** | | Digital input | Optical; **HDMI eARC** | Optical | | Digital output | Optical | **Optical and coaxial** | | Wired subwoofer output | **Yes** | No | | 12V trigger output | Yes | Yes | | USB audio or storage | No | No; USB-C is power only | | Headphone output / phono stage | No / No | No / No | | Ethernet | 10/100Mbps | 10/100Mbps | | Wi-Fi | Wi-Fi 6, dual band | Wi-Fi 5, dual band | | Bluetooth | 5.3, SBC/AAC documented | 5.0, SBC/AAC input and output | | AirPlay 2 / Google Cast | Yes / Yes | Yes / Yes | | Spotify / TIDAL / Qobuz Connect | Spotify and TIDAL documented; Qobuz added through the app roadmap, but Fosi documentation remains inconsistent | Yes; mature implementation and documentation | | Roon | **Not Roon Ready yet**; certification in progress | **Roon Ready certified** | | EQ and room tools | Graphic EQ, with features varying by app/firmware; no room correction or PEQ documented | **10-band GEQ, 10-band PEQ, per-source EQ and Room Correction** | | Display | No | No | | Main control | Rotary knob, Bluetooth remote, Fosi Audio app | Capacitive controls, WiiM Voice Remote, WiiM Home app | | Dimensions | 173 × 173 × 47mm | 140 × 140 × 42mm | Price references checked on 16 August 2026: [Fosi S3 official store](https://fosiaudio.com/products/s3-balanced-hifi-streamer?ref=soundpathlab.com), [WiiM Pro Plus at EMiUZEK](https://emiuzek.com/products/wiim-pro-plus-high-resolution-wireless-audio-streamer-with-airplay-2?ref=soundpathlab.com) and [WiiM Pro Plus at Crutchfield](https://www.crutchfield.com/p%5F399WIIMPPL/WiiM-Pro-Plus.html?ref=soundpathlab.com). WiiM's own comparison page still contains an older $219 figure, so live retailer pricing is the more useful current reference. ## The same DAC chip does not make them the same product Both devices use the AKM AK4493SEQ, but a DAC chip is only one part of a streamer. Output stage, power supply, clocking, gain structure, analogue-to-digital conversion and software all influence the finished product. The S3 has an objective hardware strength: its balanced output reaches 4Vrms. SoundStage's APx555 lab test measured **120.6dB A-weighted SNR, 114.2dB SINAD and below 0.00019% THD+N** through XLR. Those are excellent results for a $260 streamer. The same testing found that XLR provided 6dB more gain than RCA, but no appreciable THD+N advantage under the test conditions. [See the full S3 measurements](https://www.soundstagenetwork.com/index.php?Itemid=142&catid=433%3Apreamplifier-measurements&id=3054%3Afosi-audio-s3-streaming-preamplifier-measurements&option=com%5Fcontent&view=article&ref=soundpathlab.com). That distinction matters. XLR is valuable when feeding active studio monitors, a balanced power amplifier or a system with long cable runs and potential ground-noise problems. It should not automatically be described as producing a wider soundstage or audibly better fidelity in an ordinary short-cable home system. WiiM documents approximately **120–121dB SNR and -110 to -113dB THD+N**, depending on the specification page and test condition. Independent measurements have also shown excellent results. The practical conclusion is not that one has a night-and-day sonic advantage: **both analogue outputs are capable of transparent performance in a normal system**. Choose S3 for the balanced interface, not because the shared AKM chip guarantees a different sound signature. ## Analogue input: WiiM has the more convincing implementation The line input is easy to overlook, but it matters if you plan to connect a CD player, tuner, cassette deck or turntable through a phono preamp and redistribute that source to other rooms. WiiM Pro Plus uses a TI Burr-Brown PCM1861 ADC and documents conversion up to 24-bit/192kHz. It can send its physical line or optical input to compatible WiiM devices in a multi-room group. Independent testing found that the Fosi S3 converts its RCA input at 48kHz and begins clipping at approximately 2.28Vrms. That is adequate for ordinary line-level sources, but it is less ambitious and less flexible than the WiiM input path. The S3 is at its strongest as a digital streamer and DAC; it is not the better choice if high-quality analogue-source conversion is central to the system. ![Rear connection comparison showing Fosi S3 XLR HDMI eARC and sub out beside WiiM Pro Plus coax optical and line connections](https://storage.ghost.io/c/46/07/46077859-610e-4a56-b3fb-5d05be54185e/content/images/2026/08/fosi-s3-vs-wiim-pro-plus-rear-panels.png) Rear-panel comparison. Manufacturer product images: Fosi Audio and WiiM/Linkplay; layout by SoundPath Lab. ## Connections: S3 wins for TV and balanced systems; WiiM is the better digital transport The rear panels show the products' different priorities. Fosi provides HDMI eARC, XLR, RCA, optical input and output, subwoofer output, Ethernet and a 12V trigger. It can sit between a television, active speakers or power amplifier and a subwoofer with fewer adapters. WiiM provides RCA line input and output, optical input and output, coaxial output, Ethernet and a 12V trigger. It lacks HDMI, XLR and wired subwoofer output, but the extra coaxial output makes it more flexible as a transport for an external DAC. Both omit USB audio, USB storage and headphones. On the WiiM, the USB-C socket is strictly for power. Fosi's own FAQ mentions “coaxial” and “USB” when discussing possible sampling rates, but the S3 chassis has neither input. That is a documentation error, not a hidden feature. ### TV use S3 is the clear hardware winner for television audio. HDMI eARC and CEC allow TV audio and volume control over one cable. WiiM Pro Plus must use optical input, and the TV must output stereo PCM rather than Dolby or DTS. The qualification is automation. A recent S3 owner reported that the unit could switch from HDMI to TIDAL Connect or AirPlay automatically, but did not switch back to HDMI after network playback stopped. Fosi's own product manager has acknowledged that its current Wi-Fi input priority can prevent automatic return to HDMI and said the behavior was being discussed with R&D. [See the current S3 development discussion](https://community.fosiaudio.com/threads/s3-streamer-development-log.5521/page-6?ref=soundpathlab.com) and [the 90-day owner report](https://www.reddit.com/r/fosi%5Faudio/comments/1umievy/fosi%5Faudio%5Fs3%5Fstreamer%5F90day%5Fmidterm%5Freview/?ref=soundpathlab.com). So the S3 has the better TV connection, but not yet the most polished TV workflow. ## Software is where WiiM earns the recommendation A streamer is a software product that happens to contain audio hardware. On that criterion, WiiM Pro Plus has the decisive advantage. WiiM Home supports a broad service catalogue, NAS and local-network playback, input redistribution, presets, routines and multi-room control. The Pro Plus currently offers 10-band graphic EQ, 10-band parametric EQ, per-source EQ and Room Correction. Current firmware also integrates Room Correction with EQ and continues to receive stability improvements. [WiiM's official firmware history](https://faq.wiimhome.com/en/support/solutions/articles/72000611938-wiim-pro-plus-firmware-release-notes?ref=soundpathlab.com) documents the pace and scope of those updates. The Pro Plus is also [formally Roon Ready certified](https://blog.wiimhome.com/post/wiim-pro-plus-is-officially-roon-ready-certified?ref=soundpathlab.com). For a Roon user, this alone can settle the comparison. The Fosi Audio app handles core setup, source selection, playback and graphic EQ, and Fosi has continued adding features. But Fosi itself has acknowledged that the S3 app needs improvement in interface organization, feature depth, usability and the overall experience. The company has been developing a redesigned app, but buyers should evaluate what works today rather than purchasing on a roadmap. [Fosi's official app statement](https://fosiaudio.com/blogs/news/official-statement-on-the-fosi-audio-s3-app-experience?ref=soundpathlab.com) is unusually candid about that gap. The S3 is not currently Roon Ready. AirPlay or Google Cast can be used as workarounds, but they are not native Roon RAAT operation. Fosi's official product page simultaneously displays Roon-oriented marketing, lists Roon Ready in its protocol table and states that certification is still in progress. The last statement is the one buyers should rely on: **Roon Ready is not supported yet**. ## The S3 subwoofer output is useful—but it is not bass management Fosi's physical subwoofer output is a real advantage over the Pro Plus, but the implementation is incomplete for a serious 2.1 system. SoundStage found that the sub output remains active and that the S3 currently provides no user-adjustable low-pass frequency, phase control or high-pass filter for the main outputs. The main speakers therefore continue receiving a full-range signal. Integration must be handled with the controls on the subwoofer or with external DSP. [Read the independent S3 review](https://www.soundstagesimplifi.com/index.php/equipment-reviews/311-fosi-audio-s3-streaming-preamplifier?ref=soundpathlab.com). WiiM Pro Plus has no wired subwoofer output at all. A subwoofer must be connected through the amplifier, speaker-level inputs, a pass-through crossover or an external device. WiiM can integrate its separate wireless Sub Pro, but that adds substantial cost and changes the comparison. If a physical sub output is the requirement, S3 wins. If adjustable crossover, main-speaker high-pass, phase and delay are the requirement, **neither unit provides a complete wired solution by itself**. ## Fosi's specification page needs correction The S3 hardware is stronger than the quality of its documentation. The current official page makes several conflicting claims: - the promotional section says PCM up to 32-bit/768kHz; - the product description says 32-bit/384kHz; - the specification table lists Wi-Fi at 24-bit/192kHz; - the FAQ claims 384kHz over Wi-Fi and 768kHz over Ethernet; - the FAQ refers generically to coaxial and USB inputs that the S3 does not have; - Roon Ready appears in parts of the marketing while another note correctly says certification is incomplete. These discrepancies do not prove that the product sounds poor, but they make purchasing and troubleshooting harder. Until Fosi publishes one consistent signal-path table, buyers should treat **24-bit/192kHz as the clearly documented ceiling for the common Wi-Fi and optical paths**, and should treat Roon as unsupported. WiiM's pages are not perfectly synchronized either—the older $219 price remains visible—but its input/output limits, app functions, firmware notes and certification status are documented far more clearly. ## What each product gets wrong ### Fosi S3 limitations - Fosi Audio app remains behind WiiM Home in organization, library handling, DSP depth and automation. - Roon Ready certification is unfinished. - No room correction or parametric EQ is documented. - The subwoofer output lacks complete crossover, phase and main-channel high-pass controls. - HDMI input priority and automatic return behavior are not fully mature. - No coaxial or USB audio connection. - Analogue input is digitized at 48kHz. - No display or clear numerical volume readout. - Official specifications contradict one another. ### WiiM Pro Plus limitations - No HDMI ARC/eARC. - No XLR balanced output. - No wired subwoofer output. - No USB audio or USB-drive playback. - No headphone output or phono stage. - Plastic enclosure and no display. - Bluetooth is limited to SBC/AAC rather than a higher-bitrate codec. - Room correction is useful but still depends on the measurement device and setup procedure; it is not a substitute for good speaker placement. ## Which one should you buy? ### Buy Fosi S3 if: - your active speakers or power amplifier accept XLR and you want a direct balanced connection; - HDMI eARC is essential for the television; - you need a physical subwoofer output and can perform crossover adjustment on the sub itself; - you want a conventional rotary volume control; - Spotify, TIDAL, AirPlay or Google Cast cover your normal listening, and you can verify any Qobuz requirement on the current regional firmware before buying; - you are comfortable with a younger app platform and future firmware changes. ### Buy WiiM Pro Plus if: - you want the most complete and predictable daily experience; - you use Roon, NAS playback or a multi-room WiiM system; - room correction, PEQ and per-source EQ matter; - you plan to digitize and redistribute an analogue source; - you use an external DAC and want both optical and coaxial outputs; - HDMI, XLR and a wired subwoofer socket are not required. ## Final verdict At the old $219 WiiM price, Pro Plus was easier to recommend on value alone. At **$249 versus $259.99**, price is no longer the deciding factor—but the overall verdict does not change. **WiiM Pro Plus remains the better purchase for most people.** Its analogue output is already excellent, and its software platform, Roon certification, room tools, input redistribution, documentation and firmware history make it the more complete ownership proposition. **Fosi S3 is the better hardware fit for a narrower but important group.** If a system needs XLR, HDMI eARC and a wired subwoofer output in one compact box, WiiM Pro Plus cannot replace it. The S3's measured digital-to-analogue performance is genuinely excellent. Its weakness is not sound quality; it is the gap between capable hardware and a still-maturing software and documentation platform. Our recommendation status: - **WiiM Pro Plus: strong default recommendation.** - **Fosi S3: recommended with conditions—verify the exact streaming, TV and subwoofer workflow before the return window closes.** ## Buying options **WiiM Pro Plus:** [EMiUZEK](https://emiuzek.com/products/wiim-pro-plus-high-resolution-wireless-audio-streamer-with-airplay-2?ref=soundpathlab.com) · [Amazon](https://www.amazon.com/dp/B0CC2HWC7N?ref=soundpathlab.com) · [WiiM product information](https://www.wiimhome.com/wiimpro/overview?ref=soundpathlab.com) **Fosi S3:** [Fosi Audio direct](https://fosiaudio.com/products/s3-balanced-hifi-streamer?ref=soundpathlab.com) · [Amazon](https://www.amazon.com/dp/B0GL81B7P9?ref=soundpathlab.com) Prices, stock and regional versions can change. Check the seller, included power supply, warranty and return policy before ordering. ## Evidence and verification **Evidence basis:** manufacturer product pages and firmware notes; SoundStage laboratory measurements and product review; current Fosi development statements; documented owner reports used only for behavior that is clearly identified as an owner report. **Firmware and versions reviewed:** publicly documented capabilities and update status available on 16 August 2026\. Fosi's redesigned app and Roon Ready certification were not treated as completed features. **Last checked:** 16 August 2026. **Limitations:** This is not a SoundPath Lab hands-on listening test. Measurements from different laboratories or manufacturer test conditions should not be ranked as if they were collected in one controlled comparison. Streaming services and app behavior can vary by firmware, platform and region. **Commercial disclosure:** No payment or manufacturer sample determined this conclusion. Retail links are provided for availability and may be commercial links; they do not alter the product ranking or evidence status. **Images:** Manufacturer product images from Fosi Audio and WiiM/Linkplay; comparison layouts by SoundPath Lab. **Related reading:** [Fosi S3 and ZP3 problems buyers should know](https://www.soundpathlab.com/fosi-audio-s3-zp3-problems-app-hiss-buying-advice/) · [WiiM Pro Plus product profile](https://www.soundpathlab.com/product-profile-wiim-pro-plus/) · [How SoundPath Lab scores software and firmware risk](https://www.soundpathlab.com/how-we-score-bad-apps-poor-support-and-firmware-risk/) For TV-input format boundaries beyond the feature list, [see which HDMI and optical format claims are actually documented](https://www.soundpathlab.com/hdmi-arc-vs-optical-audio-which-connection-is-better-for-tv-sound/). ## Update — 24 August 2026 - Fosi's official U.S. store still lists the S3 at **$259.99** and currently advertises a 15% promotional code. The table above continues to use the normal listed price because temporary discounts can expire or vary by region. - WiiM Pro Plus firmware **4.8.826050**, dated **12 August 2026**, adds Auto Headroom to reduce clipping risk and improves multi-room audio quality. This strengthens the software-support case but does not change the comparison verdict. - Fosi's current product page now advertises Qobuz Connect setup and a 10-band EQ. Its Roon wording remains inconsistent, so SoundPath Lab still does not treat the S3 as Roon Ready without completed certification. **Recommendation status:** unchanged. WiiM Pro Plus remains the safer default; Fosi S3 remains the conditional choice for XLR, HDMI eARC and a physical subwoofer output. **Primary sources:** [Fosi S3 official product page](https://fosiaudio.com/products/s3-balanced-hifi-streamer?ref=soundpathlab.com) · [WiiM Pro Plus firmware release notes](https://faq.wiimhome.com/en/support/solutions/articles/72000611938-wiim-pro-plus-firmware-release-notes?ref=soundpathlab.com) **Last checked:** 24 August 2026.