Switch 2 Pro USB audio: physical headphone output confirmed¶

Historical record. This preserves the source, tests and limitations recorded at the time; it is not current setup guidance. See the documentation index.

Scope and result¶

2026-09-06, user-connected Switch 2 Pro over USB, controller headphone jack cabled to the PC's Realtek Line In. The user explicitly confirmed L-in and authorized controller audio testing. Tests ran portably on the Desktop while the existing b86 controller lab continued running. No installed DS4Windows, VIIPER, drivers, sound defaults, endpoint volumes, microphone permissions or Sonar settings were changed. No ambient microphone was opened or recorded.

Confirmed: standard Windows USB-audio playback physically arrives at the controller's 3.5 mm jack, with stereo channel assignment intact and bounded start/stop. There is no need for DS4Windows to invent an audio report format or route this playback through its input mapper or VIIPER.

Not confirmed: headset microphone signal, Bluetooth audio, game-specific audio selection, sample loss/quality across long sessions, or audio latency. A normal AUX-to-Line-In cable tests headphone output, not the headset's mic contact. A compatible headset microphone is needed for that acceptance test.

Evidence¶

Windows reports the physical composite device USB\VID_057E&PID_2069, with MEDIA interface MI_02 handled by usbaudio, driver 10.0.26100.8972. HID and WinUSB interfaces remain separate. WASAPI exposes active native endpoints:

• Headphones (Switch 2 Pro Controller) — render; mix float 48 kHz, stereo.
• Microphone (Switch 2 Pro Controller) — capture; mix float 48 kHz, stereo.

The Windows mix format is not a claim about the wire format. The audited USB descriptors declare alternate streaming interfaces with stereo 16-bit PCM at 48 kHz, output endpoint 0x03, input 0x83, 192-byte isochronous packets and bInterval=1. The microphone terminal and stream descriptors disagree about channel count; do not invent microphone channel semantics from their names.

The portable probe (utils/Switch2UsbAudioProbe) played a 500 ms -34 dBFS stereo tone, left 440 Hz / right 660 Hz, with 10 ms fades. It captured only the user-selected Realtek Line In and kept samples in RAM. Representative measured 100 ms blocks from the final run (60,960 captured stereo frames):

This is a manual evidence-based analog-delivery verdict, not merely the probe's successful WASAPI completion. The window timestamps are relative to capture, not synchronized DAC/ADC latency measurements. No global output was redirected; the PC's default remains SteelSeries Sonar - Gaming.

DS4Windows presentation¶

The Switch 2 Controls page now includes Use a headset over USB for Pro controllers and offline profiles (not Joy-Cons). It provides the native Headphones/Microphone selection instructions and a Windows Sound settings shortcut. It explicitly labels Bluetooth headset audio as unsupported. The shortcut only opens ms-settings:sound; it changes no setting automatically.

The existing Sony audio-routing capability gate intentionally stays closed for Switch 2. That gate controls DS4Windows-managed Sony transports; it is not a denial of the independent native Windows USB audio device. Saved Sony speaker, mic, and audio-haptics choices must not accidentally arm those routes on a Switch 2 or make its input runtime report a false startup failure.

Native USB audio selection is independent of virtual-pad type. A user may pick the physical endpoint in the game or Windows Sound settings; this work does not silently change default output, add a duplicate loopback mixer, or claim that a virtual Xbox headset has been implemented.

References and remaining boundaries¶

• ndeadly/switch2_controller_research, audited commit d1c5a7f7ba298f83017fae84952a4e6d2ef8fc92, descriptors.md and Bluetooth interface. Bluetooth exposes audio characteristics on newer firmware, but the documented 50-byte audio field is unknown format, not established raw PCM.
• Local Switch2Connect README explicitly lists wireless Pro headphone/mic audio as unsupported. No working wireless decoder was found there to copy.
• Nintendo headset microphone instructions distinguish headset-mic use through the controller jack.
• Microsoft's Windows Settings URI documentation documents the non-mutating Sound settings navigation used by the button.

No firmware flash, driver replacement, undocumented USB command, Bluetooth audio enable command, or microphone capture was attempted for this result.

Validation status¶

• Targeted audio applicability, UI policy/layout and artwork tests: 107 passed.
• Headset illustration rendered and visually inspected without clipping.
• Full Release/x64 suite: 3,892 passed, zero failed, three opt-in audio tests skipped (3,895 total). Allocation assertions remained enabled and passed. DS4WindowsTests/TestResults/full-b88-usb-headset-release.trx.
• Portable probe builds with zero warnings/errors; its source is included in this checkpoint. Main app publishes successfully (existing warnings remain).
• Live profile-card navigation and headset microphone acceptance: pending.
• The separate b87 Link/Unlink build was prepared but not launched; the running b86 session and unsaved profile edits were left alone.

Prepared portable b88¶

5.0.4.88-USB-Headset-Link-Preview includes the preceding d2f1a89 Link/Unlink/retained-pad changes. Desktop lab shortcut: DS4Windows Portable b88.lnk; runtime folder: DS4Windows-current-2026-09-06-b88-usb-headset-link. The launcher snapshots b86's saved settings only after the existing apps exit. It validates all four hashes, uses the unchanged pinned broker, and does not alter Program Files. Not launched yet, pending the user's save/exit.

SHA-256:

DS4Windows.dll 3CF7A25036EE637D2BA70498B2D16121F9CF70B991F3169CEC24D8626D393CE3
DS4Windows.exe 5E3847A02125F9084B052E0D69F2045D1D7EE27C2EE20532725D34B61E447010
viiper.exe 7B6B00CF3AC205549AF80692E45BD7785D3B8BC558A92D4FF5A1A61060592B78
xbox-one-authorized-persona.json 2A85D3395529C7305F55338E4965A7FFD4E269DDE535FA41BD98BC54D67111C4

b88 live USB re-verification¶

b88 launched elevated at 19:50 local with portable VIIPER. The physical USB Pro attached through the existing full-duplex runtime and the Overview displayed Ready, Xbox 360 output, 4.00 ms / 250 Hz report intervals. No installed software or Windows sound settings were changed.

At the user's request to verify audio first, the same opt-in physical cable test was repeated with b88 running. Output and capture endpoint identities, active state, unmuted state and prior volume were rechecked. The 500 ms test again reached Line In in the correct channels and returned to baseline:

• Before (200 ms): left/right RMS 0.000552 / 0.000536.
• During (500 ms): left 440 Hz amplitude 0.043944 vs 660 Hz 0.000146; right 660 Hz amplitude 0.043564 vs 440 Hz 0.000169.
• After (1,000 ms): left/right RMS 0.000551 / 0.000546.
• 60,960 stereo frames captured in RAM; no audio saved, no controller errors appended to the b88 log during the test. Microphone signal remains untested.

Computer-use inspection exposed unsupported Sony output-level controls on Overview; a follow-up correction is in progress. Profile navigation could not be confirmed through the lower-integrity UI helper, so no successful live headset-card navigation or Link/Unlink hardware acceptance is claimed.

Five-level headphone-out to Line-In verification¶

The user explicitly requested signal-level verification. Five 500 ms stereo tests were played sequentially at source peaks 0.005, 0.01, 0.02, 0.04 and 0.08. The script stopped before any higher step on missing signal, an elevated baseline (>0.01 RMS), insufficient capture, or a captured peak >=0.90. No stop condition occurred. The existing Windows endpoint levels remained unchanged: controller render scalar 0.5000053, Realtek Line In scalar 1.0.

Baseline noise energy was subtracted before RMS/gain comparisons. The expected doubling is 6.0206 dB; the largest measured deviation was 0.076 dB. The frequency-specific channel separation at the sampled plateau was 42.35 dB or better. Detailed numeric results are in 2026-09-06-switch2-usb-audio-levels.json (metrics only, not recorded audio).

Verdict: stereo levels match within 0.06 dB and relative gain tracks the source across the tested range, with no captured full-scale clipping. This does not mean input/output normalized numbers are identical: the measured DAC-to-ADC chain has approximately +6.8 dB gain (~2.2x normalized amplitude). It also does not certify voltage calibration or full-volume headroom. A linear extrapolation predicts that sufficiently loud source peaks could clip this PC Line In; full-volume playback was not attempted and no automatic compensating gain was baked into DS4Windows. Headphone use and PC Line-In capture are different loads/routes. Windows volume scalars are audio-tapered controls, not linear amplitude percentages (Microsoft documentation).

DS4Windows compatibility follow-up¶

Overview now provides the same native USB headset setup/Windows Sound settings action as Profile settings. Sony-managed speaker, EQ and microphone controls are hidden for incompatible physical controllers. Their view-model setters also reject inapplicable edits, and a hidden audio-source binding cannot rewrite a shared profile during normalization. Genuine Sony audio controls still work; input mapping, rumble, virtual-pad selection and native USB audio routing are unchanged. There is deliberately no duplicate capture/playback buffer or fake Switch 2 speaker toggle: games select the real Windows USB audio device.

Nine new Overview regression cases pass. The full Release suite passes 3,901 tests, zero failures, three opt-in audio skips, including allocation checks. The real Overview control was also rendered at 760 and 1100 DIP and inspected; native headset guidance is visible for Pro, Sony audio controls remain visible for Sony, and neither is advertised as a Joy-Con headset capability. Portable b89 packaging/live acceptance is pending at this checkpoint.

b89 package checkpoint¶

The final USB Release suite again passed 3,901 tests with zero failures and three opt-in audio skips (full-b89-usb-audio-final.trx). The portable package was published successfully as 5.0.4.89-USB-Audio-Preview, with the unchanged pinned VIIPER and persona. All four launcher hash checks pass. Desktop lab shortcut: DS4Windows Portable b89.lnk. Its first launch snapshots b88's saved settings only after both older portable processes exit.

DS4Windows.dll D7B07C5200EBA49A4876F38F97A6827D6875821849D8D88EDC3FF70BA6C3F283
DS4Windows.exe 70CC5340B439C746991B54CFC68F1CDC86990037A64FA8E0EC36FA7D534C0ECE
viiper.exe 7B6B00CF3AC205549AF80692E45BD7785D3B8BC558A92D4FF5A1A61060592B78
xbox-one-authorized-persona.json 2A85D3395529C7305F55338E4965A7FFD4E269DDE535FA41BD98BC54D67111C4

Prepared, not launched. The old elevated b88 still displays Overview, Ready, USB 4.00 ms / 250 Hz, with no open profile editor. The lower-integrity computer-use helper could inspect it, but its settings click produced no navigation. The normal close action minimizes under the user's saved setting; source inspection confirmed portable mode rejects legacy WM_COPYDATA IPC. No bypass, force-kill or in-memory settings manipulation was used to close it. No b89 live UI acceptance or completed runtime replacement is claimed.

The user's additional Bluetooth-audio request is tracked in 2026-09-06-switch2-bluetooth-audio-audit.md. Its offline Opus idle-pattern result is not a claim that wireless headset audio now works.