IQ sound pipe

[madeuf]

I'm currently writing a decoder for my SDR using CubicSDR for receiver, then pipe the raw IQ data through soundcard for later uses.
However, I'm confused about how the IQ file is sent (in what format). By using python and pyaudio, the .wav file I get has only one dimension, but the record function of CubicSDR outputs .wav files with dimension of 2 (I and Q, of course). Can someone tell me about how the audio is piped through the soundcard and what the format is? I've looked at all the documentation but couldn't find anything.