Control sound line-in

How Can I control (tune up or down) the level of the line-in or microphone channel? and how开发者_如何转开发 can I visualize the spec (as a graph or something)?

Also see Alvas.Audio RecordPlay example http://alvas.net/alvas.audio.aspx

you can try using the mixer APIs to find the line in volume control. I've found it is very tricky to pick out the right one (especially if you want it to work in both XP and Vista/Win7). Have a look at .NET Voice Recorder for an example of how to use NAudio to do this.