多蓝牙音频设备同步播放的跨平台实现方案问询

Hey there! I totally get your frustration—so many sources claim Bluetooth 5.0 is a non-negotiable requirement for syncing audio across multiple devices, but as you’ve noticed, connecting multiple Bluetooth audio devices is already doable on most systems; we just need a way to route audio to all of them simultaneously. Let’s break down practical options for each platform you’re targeting, plus dive into your streaming-based workaround idea and sync latency fixes:

Android #

• Built-in Features: Samsung’s Dual Audio (available on select Galaxy models) lets you pair two Bluetooth devices at once, but it’s often restricted to Samsung’s own buds/speakers or certified third-party gear. Your Galaxy A51 might lack this feature because it’s limited to higher-end Galaxy devices or newer software builds.
• Third-Party Apps: Tools like Samsung’s SoundAssistant (check if it’s compatible with your A51) or third-party apps like Audio Router can route audio to multiple Bluetooth devices. Many of these apps even support assigning left/right channels to specific devices. Keep in mind that without Bluetooth 5.0, you might encounter minor latency, but most apps include sync adjustment sliders to line up audio perfectly.
• Streaming Workaround: If native Bluetooth routing falls short, try a local Wi-Fi stream. For example, use VLC on your laptop to stream audio locally (go to Media > Stream, select your audio source, choose HTTP as the output, and set a local URL like http://localhost:8080/stream). Each device can connect to this stream via a browser or VLC app, and you can adjust playback delay on each device manually to sync them.

macOS #

• Native Aggregate Device: macOS has a built-in Aggregate Audio Device tool (found in Audio MIDI Setup). You can add multiple Bluetooth audio devices to this aggregate, then set it as your default output to route audio to all devices at once. For left/right channel control, use Audio MIDI Setup to map specific channels to each device in the aggregate.
• Third-Party Tools: Apps like SoundSource offer more granular control—you can split left/right channels to different Bluetooth devices and adjust sync offsets to fix latency gaps. No Bluetooth 5.0 is required here; aggregate devices work with older Bluetooth versions, though you may need to tweak sync settings for smooth playback.

Windows #

• Native Multi-Output Device: Windows 10/11 includes a Multi-Output Device feature (head to Settings > System > Sound > More sound settings, right-click in the list, and select "Create Multi-Output Device"). Add your Bluetooth devices to this setup, set it as the default output, and audio will play on all connected devices. For channel assignment, use the Sound Control Panel to adjust each device’s channel configuration.
• Advanced Routing Tools: Apps like Voicemeeter Banana are perfect for custom setups—you can split left/right channels to different Bluetooth devices and use built-in delay controls to sync playback flawlessly. This works with any Bluetooth version, as the app handles audio mixing on your PC before sending it to devices.

iOS #

As you suspected, iOS’s locked-down ecosystem makes this extremely challenging. There’s no native way to route audio to multiple Bluetooth devices at once, and most third-party apps are blocked from accessing low-level audio routing. The only exception is Apple’s AirPlay 2, which syncs multiple AirPlay-enabled speakers, but this doesn’t work with regular Bluetooth devices.

Streaming-Based Workaround (Your Idea) #

You’re onto a solid alternative with local streaming—this bypasses Bluetooth’s multi-device limitations entirely. Here are some lightweight options:

• VLC Streaming: As mentioned earlier, VLC’s built-in streaming feature is easy to set up for local audio. You can stream from your computer to any device on the same Wi-Fi network, then adjust playback delay on each device to sync audio.
• C# Custom Solution: For a tailored C# setup, use the NAudio library—it handles audio capture and HTTP streaming. You can build a simple server that streams audio, and add logic to let each client adjust its playback delay to stay in sync with others.

Latency & Sync Tips #

• Most third-party tools and native aggregate/multi-output devices include delay sliders—start with small adjustments (10-50ms) until audio lines up perfectly across devices.
• Wi-Fi streaming will have slightly more latency than direct Bluetooth, but manual sync adjustments can easily compensate for this.
• Even without Bluetooth 5.0, syncing 2 devices should work smoothly on most systems; you might notice minor glitches if you add more than that, but it’s worth testing.

Hope these suggestions point you in the right direction! Feel free to share any workarounds you discover that work well for your setup—we’d love to hear about it.

备注：内容来源于stack exchange，提问作者Foxyz