ASIO Multi Client Wrapper

I managed to compile Audacity with ASIO support, and everything works fine selecting the ASIO4All device, but when I attempt to select the Multi Client Wrapper (that would allow Audacity to share control of the sound card with a low latency MIDI Synthesiser) it crashes. Now, I’ve noticed that when selecting the ASIO Host, the device gets opened and closed multiple times, and its frequency is set to 192000 Hz, which is probably what crashes the Multi Client Wrapper.
Can you think of any way to fix this without buying a further sound card?

The only thing that comes to mind is if you have set the default sample rate in Audacity to 192000 (Edit > Preferences > Quality).
Check that the default in Audacity is set to a sensible setting that you know is supported by your sound card, and check that ASIO4All is set up the same (probably 44.1 or 48kHz).

You might also need to adjust the Windows default sample rate for Playback and Recording devices. See Setting the Sample Rate in Windows Vista and 7

Both Audacity’s default frequency, the project’s frequency and Windows default frequency are set to 48000 Hz, but Audacity temporary sets it to 192000 Hz when initialising the ASIO device. I also have another problem but I guess I should make another thread for that.

What exactly is the Multi Client Wrapper - a software application?

What sound card are you using?

Slow load after ASIO build (Windows 7) may be relevant. You could try recompiling Audacity with the changes mentioned there. Let us know.


It’s a hack by Steinberg that may (if it works) allow multiple applications to access the same ASIO device at the same time (otherwise multi-client support requires hardware mixing to be available in the sound card / audio device, which is not common except for some pro-level devices).
It is not officially supported by Steinberg
or by ASIO4ALL Re: Cannot use two audio apps at the same time... | ASIO4ALL

Steinberg work around this limitation by using Rewire to pipe audio between applications, but Rewire is closed source proprietary software which cannot be legally supported by Audacity Missing features - Audacity Support

ASIO and Rewire together provide similar functionality on Windows as Jack does on Linux.
Jack is also available for Windows. I don’t know how stable it is on Windows but if you don’t want to upgrade to Linux it may be worth trying Using JACK on Windows | JACK Audio Connection Kit

Now the frequency doesn’t get set to 192000 Hz, but I still can’t use the Multi Client Wrapper, but I guess there isn’t much to do about it.
It’s still something worth mentioning in the Wiki page about ASIO.

Thanks for the suggestion. It isn’t very stable on Windows from what I’ve seen, though it could be useful in the future.

Thanks for the explanation, Steve.

You can actually aggregate non-ASIO devices in the ASIO4ALL control panel, as I understand it.

If you wanted to try JACK on Windows with Audacity you would need to define the JACKSDK_DIR environment variable to point to the JACK installation directory.


“Multi Client Wrapper” is the other way round - it allows multiple applications to access one device.

Yes, I got that but didn’t explain what I meant fully.

I was just wondering if it was a non-ASIO device that you could use Virtual Audio Cable or similar to duplicate the inputs of the single device and work round the application exclusivity that way.


Apparently that is possible, but perhaps not very reliable. I’ve not tried that myself but I hear that it “sometimes” works. It’s not really how ASIO was designed to be used.

I’ve tried Jack with Audacity, and it works perfectly.
Only silly thing is that every time I start to record I have to pause to connect the MIDI synthesiser to Audacity, because Audacity isn’t listed when not playing or recording, and the program doesn’t seem to remember the previous configuration, but overall it’s a very good software.
Thank you so much

Thanks for letting us know JACK was a solution to connect multiple applications.

Yes there is a list at Missing features - Audacity Support of Audacity’s JACK limitations.