HELP CENTER · AUDIO GUIDE

Audio routing on Remio.

System audio, per-app routing, microphone passthrough, output device selection — the complete audio stack, documented step-by-step for macOS and Windows hosts.

Last updated 2026-05-27 5 steps · ~3 min 48 kHz · low-latency mode

Remio carries audio on the same end-to-end encrypted channel as video. The host captures whatever your speakers would play and forwards it to your client in real time, at the sample rate and latency settings you choose. This guide covers system audio versus per-app routing, microphone passthrough back to the host, and how to pick the output device on the client side.

Overview

Remio's audio path mirrors its video pipeline. On macOS, the host installs a small virtual aggregate device the first time you enable audio capture — this device taps the system mix without changing your defaults, and you can pin it to a single application if you want per-app isolation. On Windows, capture goes through WASAPI loopback, which already supports both system and per-app capture natively. Either way, the captured stream is encoded with Opus, encrypted with AES-256-GCM, and rides the same data channel as your screen.

Latency is the headline number. With Low-Latency Mode enabled, the round-trip from host capture to client speaker sits at roughly 5 to 8 ms on a LAN, well below the threshold where you would notice a lip-sync gap or a delayed key click in a DAW. With the mode off, the buffer grows to about 40 ms — still imperceptible for video and meetings, and noticeably more robust on flaky Wi-Fi.

Prerequisites

  • Host running macOS 15 Sequoia or later, or Windows 10/11.
  • Client running iOS 18, iPadOS 18, macOS 14, Android 10, or Windows 10 — all current Remio builds include audio support.
  • Microphone permission on the client OS, if you plan to use mic passthrough.
  • Active streaming session — audio settings only appear when a session is live.
  1. 01

    Enable audio capture on the host

    Audio capture is off by default — Remio asks before tapping anything that could carry private content. Turn it on once and the host remembers across reboots.

    macOS

    Click the Remio ember dot in the menu bar, choose Preferences → Audio, and toggle Capture system audio. The first time you enable it, Remio prompts you to allow the installation of a virtual aggregate device named Remio Audio. Approve once; the device stays installed and never becomes the default unless you choose it manually.

  2. 02

    Choose source — system or per-app

    Two source modes cover the common workflows. System Audio sends everything that would normally come out of the speakers; Per-App isolates a single application so it does not leak into anything else playing locally.

    • System Audio — best for gaming, watching media, or sharing a mixed soundscape. The client hears whatever the host would play.
    • Per-App — best for routing a single source. Useful for streaming a game's audio while a music app keeps playing in the background, or for sending a meeting's audio without forwarding system notifications.

    The dropdown lists every application currently producing audio. Pick one, and the host filters its capture to that program only. Switching apps mid-session is instant — the new source begins streaming on the next audio frame.

  3. 03

    Set sample rate and low-latency mode

    The sample rate dropdown offers 48 kHz (default) and 44.1 kHz. Match it to the source if you care about avoiding resampling: 48 kHz is the standard for video, games, and operating-system mix; 44.1 kHz is the standard for music and most DAWs.

    Low-Latency Mode is a separate toggle. On, it shrinks the audio buffer to ~5 ms — the sub-frame end-to-end latency you want for live music collaboration, gaming, or any application where audio cues drive timing. Off, the buffer grows to ~40 ms, which is still inaudible for meetings and media, and gives you more headroom on weaker networks where occasional packet loss might otherwise cause an audible blip.

    WHY

    Low-Latency Mode trades buffer for responsiveness. On a strong LAN, the trade is free; on a marginal Wi-Fi link, the buffer absorbs jitter that would otherwise become a pop.

  4. 04

    Pick the output device on the client

    By default the stream plays through whatever output the client OS has selected — the iPad's speaker, the laptop's headphones, the Mac's connected display. You can override this per host from the in-session toolbar.

    Open the floating toolbar, tap the audio icon, and pick an output device from the list. The choice is sticky per host: connect to the same Mac tomorrow and Remio remembers you wanted AirPods. Switching outputs mid-session is gapless — audio crossfades from one device to the next within a single frame.

  5. 05

    Enable mic passthrough (optional)

    Microphone passthrough is the reverse direction: the client's mic becomes an input device on the host, available to any application that lists microphones. Enable it from Preferences → Audio → Microphone Passthrough on the host.

    On the client, you'll be prompted for microphone access on first use. Approve once and the mic is wired straight to the host as Remio Microphone. Pick that device in Zoom, Teams, Discord, OBS, or any other app that asks for an audio input, and the host treats it indistinguishably from a USB mic plugged into the machine itself.

    # Typical mic-passthrough setup
client → enable Microphone permission in OS
host   → Preferences → Audio → Microphone Passthrough on
host   → open Zoom/Discord/OBS
app    → pick "Remio Microphone" from the input list
session → mic audio flows client → host in real time

Troubleshooting

  • No audio on the client — verify Capture System Audio is toggled on in host preferences. On macOS, also check that the Remio Audio aggregate device is installed (System Settings → Sound → Output).
  • Crackling or dropouts — turn Low-Latency Mode off and let the buffer expand. If the link is congested, drop the video bitrate too — audio shares the same data path.
  • Echo or feedback — happens when both ends play through speakers without a headset. Wear headphones on one side, or mute the host speakers and rely on client playback only.
  • Per-app source missing — only apps currently producing audio appear in the list. Start the application, play something for a second, and the dropdown will refresh.
  • Mic passthrough not appearing on host — confirm microphone permission on the client OS, then quit and relaunch the client app.

If none of these resolve it, the broader audio troubleshooting guide walks through drift, sample-rate mismatches, and silent-session causes in more depth.

FREQUENTLY ASKED

Common audio questions

Does Remio stream audio along with video?

Yes. Remio captures system audio on the host and streams it on the same encrypted channel as video, synchronized to within 20 ms at 48 kHz by default.

Can I route only one app's audio over Remio?

Yes. The host preferences include a Per-App source selector — pick any running application and only its audio is routed, leaving the rest playing on the host's local speakers.

Does the client's microphone work on the host?

Yes, when Microphone Passthrough is enabled. The client mic appears as a standard input device on the host, available to Zoom, Discord, OBS, or any other app that lists audio inputs.

What sample rate does Remio use?

48 kHz by default, with optional 44.1 kHz for music applications that prefer it. Both are matched end-to-end so no resampling artifacts are introduced in the pipeline.

What is Low-Latency Mode for audio?

Low-Latency Mode shrinks the audio buffer to roughly 5 ms, useful for music production or gaming. It costs a small amount of network robustness — leave it off on weak Wi-Fi for the cleanest playback.

Why is the microphone option greyed out on macOS?

macOS requires explicit Microphone permission for the client app. Open Settings → Privacy & Security → Microphone and toggle Remio Client on, then re-launch the app.