New Post: Resample problem

If I use

WaveFormat waveFormat = new WaveFormat(44100, 2); 
mixer = new MixingSampleProvider(waveFormat);

everything is ok with the WaveFormatConversionStream. But then I'm trying to save mixed song to the disk like this

WaveFileWriter.CreateWaveFile(mixedSong, new SampleToWaveProvider(mixer));

I recieve error: "Must be already floating point".