Thanks Mark!
It works!
Have no idea if this is completely correct, but it works and I'm happy with it.
memStream.Position = 0; using (RawSourceWaveStream NewReader = new RawSourceWaveStream(memStream, format)) { WaveStream ws = WaveFormatConversionStream.CreatePcmStream(NewReader); WaveOut wo = new WaveOut(); wo.Init(ws); wo.Play(); NewReader.Close(); }