Problems with recording audio from soundcard and microphone at the same time

Aug 21, 2014 at 9:33 AM
Hi!

I'm developing a desktop application in WPF using NAudio to record Skype calls. I'm using following main components to retrieve audio signals:
  • A WaveIn listens to client microphone. This is for recording my voice.
  • A WasapiLoopbackCapture gathers sound from client soundcard. This is for recording voice of person I'm talking with.
The two above audio data are saved to one MemoryStream and the stream is written out to a wave file using a FileWriter.

I made the call with my partner via Skype and we heard each other clearly.

The problem is: After recording, I played back the recorded file and I could hear my voice normally, but I couldn't hear my partner's voice clearly. His voice sounds nearly quiet so it's very hard to recognize what he's saying about.

My questions:
  1. What is the correct way to develop this kind of application? For recording audio from mic and soundcard simultaneously? Is there any sample app using NAudio for my references? I don't prefer Skype API as it's already closed.
  2. I tried to boost the volume programmatically, but the sound signal from my partner introduced hiss noise. So I suppose boosting volume should not be a wise way to solve my issue, right?
  3. What is the best settings for recording audio with NAudio (bit-rates, freq...)?
I'm not very experienced. Any help will be much appreciated.

Kind Regards.