Appendix A: Multi-client audio FAQ
Q: What is “Multi-client audio”?
Multi-client audio is a feature that lets you use different virtual outputs on
your Indigo product with different applications at the same time. This way,
you can use several different audio applications with just one Echo card.
Otherwise, you would have to use a different audio device for each audio
application.
For example, suppose you own both Cubase (multitrack audio) and Reality
(software synthesizer). You can now set Cubase to play out through outputs
1 through 6, and set Reality to play out through outputs 7 and 8. In previous
Echo card drivers, you had to choose between one software program and the
other.
Note:
Multi-client audio is always enabled with the WDM driver.
Q: So what's the catch?
The catch is this: all the apps using the Echo card at the same time must be
set at the same sample rate. This is a limitation of the hardware.
Say that you didn't follow this rule in the previous example. Say that you
initially had Cubase and Reality set up for 44.1 kHz- so far, so good. Then
you load a song into Cubase that is set up for 48 kHz. Cubase will change
the sample rate of the hardware. Unfortunately, this means that Reality is
now also coming out at 48 kHz, so all the sounds played out of Reality will
sound higher in pitch.
If you're planning to use multi-client audio, the best thing you can do is to sit
down and plan it out. Make a chart of each virtual output on your Indigo
product and write down what application is going to use what virtual output.
Go through all the applications you plan to use this way, set them all up for
the same sample rate, and set up their inputs and outputs correctly.
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