PRAXIS and Windows Soundcard Mixers
Praxis establishes a usable set of mixer settings when the calibration "wizard" is run, then simply restores that set of settings when Praxis is started or when the selected A/D or D/A device is changed. But Praxis can only do this for Windows system mixers -- that is, the mixers that are accessed by the Windows sndvol32.exe applet. There is no way for Praxis to know about nor to manage other exclusive mixer programs, nor about physical selector gain controls (such as manual switches or hardware physical potentiometers).
Example Windows System Mixer (sndvol32.exe) applet which can be managed by PRAXIS.
There can be a windows mixer for each sound device that Windows "knows about". But there may not be one for all devices, or some devices may have a mixer for only playback, but not for record.
Praxis decides which mixer (if any) to restore to known settings, based on the selections made in its "Device-Mixer Matching" form. The pairing in this form defaults to those identified by the Windows system. But since this is not always reliable, this form is intended to let you change the associations if they should be incorrect.
How can I tell if my soundcard device has a sndvol32.exe mixer?
A). Try this: start Praxis, and go to its Main Form. Use the
menu "Config Mixer". This will bring up the "Device-Mixer
Matching" form. This should list all of your audio devices and the Windows
system mixers that appear to be matched to them.
Note that this form doesn't select the mixer or soundcard for use, it only tells what system mixers (if any) Praxis should use with each soundcard device and function, should they later be selected.
The actual soundcard to be used by Praxis is selected using the
Levels Form's "Setup, D/A&A/D" menu. This selection will
also be the start-up soundcard next time PRAXIS is used, provided you allow
PRAXIS to save its "hardware dependent" settings when you close the
Your soundcard device should appear in both the "Input" and "Output" sections, and to the right of it should be the mixers which Praxis assumes are to be used with it.
If the mixer name reads "NONE" (or a wrong mixer name, such as that of another soundcard device on your system):
Click on the assigned mixer name to highlight it, then on the Edit button just above. That will list all the available Windows system mixers in your system. If none match your soundcard (usually the mixer has the same name as the card), then the card has no Windows system mixer --many professional card don't. If one does match, select it, then do the same process for both Input and Output devices, and click the Ok button when the matching of all devices appears proper.
If the card does not have a Windows system mixer, it may have a custom interface mixer. BUT -- Even if it DOES have a Windows system mixer, it may still also have a custom interface mixer (the EGOSYS U24 USB sound device does this -- it has both a simple Windows system mixer and a complex custom mixer in its own control application, which is best not used at all for Praxis operation). Praxis cannot control a custom interface mixer, it can only control the features which can be seen through the common Windows system mixer interface. So if there is a custom mixer application, these settings must be arranged for Praxis use (any monitoring functions disabled, soundcard inputs and output levels selected to avoid clipping) and kept stable between uses of Praxis.
B). You can also see the Windows mixers by doing the following:
Use the Windows Start button, then select Run. Type in "sndvol32.exe", then click "Ok". The windows mixer control applet should appear. Use the "Options, Properties" menu of this applet, and the topmost dropdown box can be used to see all the system mixers which are available (different ones may be present for playback and record functions, selectable in the radio buttons on this applet).
It is important to know that the mixer which is shown controlled in this applet when it is started is the default mixer for the "Default" soundcard used by Windows (for making its annunciator sounds or playing general audio). You also see this applet appear during the calibration wizard process -- it will not necessarily appear showing the controls for the soundcard Praxis is cailbrating for, because the sndvol32.exe applet always first appears with settings for the default soundcard -- that is why you often need to change the settings (using its "Options, Properties" menu) per the instructions in calibration process, to get the controls for the desired mixer.
About Windows Mixers:
Later versions of PRAXIS provide a menu in the "Levels Form" for opening the Windows mixer.
Record Mixers (also called "Capture" or "Input") usually allow selection of only one input source. So below each source, there will usually be a checkbox labeled "Select". You will want only the one for "line input" to be selected (and the others muted or turned all the way down, except possibly for a master record control).
Playback Mixers (also called "Play" or "Output") usually allow selection of multiple sources to be mixed into the output. You will want to mute (and turn down) all sources except for the Wave and possibly for any master volume or "Play Control" sliders.
If you can't open a windows mixer, and there is no "yellow speaker" icon in your Windows tray, go to your Sounds and Media tab of the Windows Control Panel. You should find a checkbox on the "Sounds" tab to "show volume control on the taskbar". Check that, click "Apply" and the icon should appear. Note that some soundcard devices do not have any Windows mixers! These can still be used with Praxis.