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Windows Sound Mixer Perpetually Scrambled by DAX?

K4SCK4SC Member
edited May 2019 in SmartSDR for Windows

I use my PC for several purposes, one of which involves listening to streaming audio from various commercial sources (iTunes, SiriusXM, Netflix, etc.)  It seems that each time I have installed any version of SmartSDR for Windows, my audio gets lost.  When I go to the Sound Mixer to find out where it has been reassigned to, usually if not always it is assigned to a DAX channel.  This happens with Windows 7 & Windows 10.  At times I do not see my previously available speaker output.

I know there must be a simple explanation and fix for this, but I have not been able to figure it out.  My end goal is to be able to Operate my Flex-6500, then watch or listen to iTunes or watch a movie without doing an easter egg hunt in control panel each time.  I currently have the latest version of SmartSDR loaded onto an i5 Windows 7 PC with the described condition, but it has occurred on several other PCs I have tried as well.

Please point me in the right direction!  Tnx de K4SC

Completed · Last Updated


  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited May 2019
    Welcome to the wonderful world of Windows.  Whenever a new sound device is installed or enabled, Windows does a complete re-enumeration of the installed sound devices.  During this re-enumeration, to frustrate you even more, Windows will also reassign the default sound devices.  it does all this in the name of convenience; meaning it tries to make logical decisions for you and set up the PC as it thinks you want it done (yes, the last sentence is sarcasm).

    So I have a question.  Do you uninstall the DAX drivers before doing an update to SmartSDR?  If so, this is compounding the behavior you are observing because you are removing a bunch of Windows sound devices from your PC which is forcing a serious re-enumeration of the Windows sound devices.

    It is not necessary to remove any installed kernel mode drivers (DAX and FlexVSP) before doing an software update unless explicitly instructed to do so in the SmartSDR release notes.
  • Ray Andrews, K9DURRay Andrews, K9DUR Member ✭✭
    edited September 2017
    Blame Windows.  I also have to go into some of my other programs that use  soundcards & re-assign them to the correct soundcard.

    In earlier versions of Windows, the soundcard was assigned by device number & not by name.  When you added or removed sound card devices, all of the soundcard device numbers were re-assigned by Windows.  Therefore the device that used to be device #1 might now be device #3, etc.

    Later versions of Windows allow you to assign soundcard devices by name.  Therefore, if your software uses the new method of assigning a soundcard device, then it does not change when you install DAX.  However, if th esoftware uses the old device number method, you will have to re-select the soundcard since the device numbers will have been scrambled.   This is especially annoying if the program (MMTTY is an example) only allows for a limited number of sound card devices.  The device you want may not appear in the list.

    73, Ray, K9DUR
  • K4SCK4SC Member
    edited November 2016
    Yes, I have been completely reinstalling all aspects of SmartSDR each time, which I now understand was unnecessary.  I will give it another try tonight.
  • K4SCK4SC Member
    edited November 2016

    I'm a little confused by your use of "Soundcard" and "Device".  My PC has only the built in Soundcard, none additional.  I want to be sure you meant soundcard outputs, as in one soundcard can switch between different speakers or other driven devices.

    As a followup, I have added a USB Bluetooth adaptor to allow me to listen with my stereo.  I would assume this is not considered as an additional soundcard, but rather as an additional selectable output from the motherboard's sole soundcard device.

    Obviously I'm not a PC guru.

  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    I am fairly certain that your results will be more satisfactory.

    As part of my job responsibilities, over the past 3 years, I installed and uninstalled hundreds and hundreds of SmartSDR versions.  I NEVER uninstall the FlexVSP drivers or DAX. Never.  I never have any issues as long as I have an active (mic and speakers plugged in) default sound device (my onboard sound card).  This prevents Windows for selecting a new default sound device for me.
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    I'm a little confused by your use of "Soundcard" and "Device". 

    The terms are interchangeable. Sound card was used for years then Windows started calling them sound devices.
  • DH2IDDH2ID Member ✭✭
    edited December 2016
    This program http://audioswit.ch/er?utm_source=client&utm_medium=direct&utm_campaign=client_1_7_0_117
    could help you. I use it all the time to switch to different audio sources.
    73, Alex - DH2ID
  • K4SCK4SC Member
    edited November 2016
    Thank you, I will check it out when I get home in a couple of hours.
  • Mike_W7TUSMike_W7TUS Member ✭✭
    edited November 2016
    When I installed V1.9.13 I unintentionally uninstalled FlexVSP.  I can't find it on the Flexradio site.  Can anyone point me towards it?
    Mike W7TUS
  • Jay NationJay Nation Member
    edited November 2016

    FlexVSP is rolled up inside V1.9.13. Reinstalling V1.9.13 again might be required. First though I'd try running the C:Program FilesFlexRadio SystemsSmartSDR v1.9.1364-bit DriversVSPFlexVSPInstaller_64.msi file, right-click on it and choose Install.

    73, Jay - NO5J

  • Mike_W7TUSMike_W7TUS Member ✭✭
    edited November 2016
    That solved the problem.  Thanks Jay.

    Mike - W7TUS

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