On 20/01/2016 00:20, Jim Brown wrote: > In the digital world, the common reference is dBFS, where the reference > is to digital clip. Hi Jim,
agreed and in the consumer world of Windows audio drivers the level slider in the properties is referenced to 0dBFS when it is set to display dB readings. Many sound card drivers also have a second slider for input devices (in the older ones a simple +20dB check box) that adjusts gain from 0dB to 40 or 50dB. This second slider is pre-ADC gain normally in 10dB steps. That is there for microphones that have output levels well below the normal line level specification. For a line level input like the DATA audio feed from a rig no pre-ADC gain should be needed so both sliders should be at 0dB i.e. 0dBFS with no analog boost. So the level slider on the Windows device driver properties is in the digital domain and should be set to 0dB. The only reason for having it elsewhere is when it is the last chance to set the level before returning to the analog domain or when mixing the stream with another. I have seen some sound cards where the driver only has a single input level slider, I assume these either have two input jacks, one with gain for microphones and one without for line levels or they combine pre-ADC gain stages in +ve dB settings and digital attenuation in -ve dB settings. Whichever way, with WSJT-X which has its own input digital gain/attenuation the 0dB setting is still optimal for the driver input level slider(s). 73 Bill G4WJS. ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ wsjt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/wsjt-devel
