Sound card input into the web audio API

Hi, I am working with a team of web developers who are trying to replicate the functionalities of a modern DAW in the web browser mainly using the web audio API. We have encountered a hurdle for which I need help. We want to be able to recognize audio inputs from an external sound card (2-4 inputs) as individual mono audio sources in the web audio API. The API accepts only 1 mono input (using a channel splitter) from the sound card and 1 stereo input (in this case using two channels). We would like to have the audio data from upto 4 of such inputs from a single sound card buffered individually to 4 different source nodes. If you don't have experience working with the web audio API please don't bother to bit. Thanks