Solved How to set default ASIO device?

This is the output of a Portaudio device query. It shows Realtek as default ASIO device. How to change that to something else?

The thing is, I have Realtek disabled through "mmsys.cpl". I could remove the Realtek ASIO driver, but I use it incidentally.

I was paddling my way through ASIO just the other day and learned a few things-

With credit to Copilot, I offer these thoughts:

ASIO doesn’t have a system‑wide “default device,” so Windows can’t change it. What PortAudio is showing there isn’t a Windows default — it’s simply the first ASIO driver registered on the system. ASIO bypasses the Windows audio stack entirely, so disabling Realtek in mmsys.cpl won’t affect ASIO enumeration.

PortAudio’s ASIO host API uses Steinberg’s SDK, and the SDK doesn’t expose any mechanism for setting a preferred ASIO driver globally. Each ASIO‑based application chooses which driver to load. Some apps remember your last choice, but none of them read a “default ASIO device” from Windows.

That’s why Realtek ASIO still shows up as the default even though the hardware is disabled.

If you want PortAudio (or any ASIO‑based app) to use the BEHRINGER UMC404HD driver, your options are:

• Select the BEHRINGER ASIO driver inside the application. Every ASIO host has its own device selector. PortAudio apps must choose the driver explicitly.
• Uninstall the Realtek ASIO driver. This forces PortAudio to enumerate only the BEHRINGER driver. Since you use Realtek occasionally, you can reinstall it later.
• Use WASAPI instead of ASIO if your workflow allows it. WASAPI does respect Windows default device settings and avoids this issue entirely.
• Avoid ASIO4ALL unless you need aggregation. It can override device order, but it’s a wrapper, not true hardware ASIO.

Non‑obvious detail: Realtek’s ASIO driver tends to register ahead of third‑party interfaces in the system’s CLSID list. PortAudio simply reports whichever driver appears first — not whichever device is enabled, active, or preferred.

So the behavior you’re seeing is normal for ASIO, even though it looks wrong from a Windows perspective.

Hope this helps

Thank you, that was very useful!

(WASAPI is a no go, probably the UMC404HD driver, as get only two output channels from it. WDM-KS
works fine as ASIO alternative and no need to guess what the mixer does)

Thanks.

ingoogni said:

Thank you, that was very useful!

(WASAPI is a no go, probably the UMC404HD driver, as get only two output channels from it. WDM-KS
works fine as ASIO alternative and no need to guess what the mixer does)

Thanks.

Click to expand...

You’re welcome — glad the explanation made things clearer. ASIO can be a bit of a rabbit hole, especially when Windows settings appear to matter but actually don’t.