I record a podcast, which has so far consisted of four people around a single microphone. After editing, I export at 64kbps mono. This week we're planning to record with two microphones on the table and I plan to export a stereo file, but I'm not sure what bitrate to use to get the same level of quality.
If I were using "simple" stereo, I would have to export at 128kbps (64kbps on each side) in order to get the same quality. However, I understand that it may be a good idea to use Joint Stereo, since the two microphones are likely to pick up a lot of the same sound with only minor differences between them. This would mean that I could achieve the quality of 64k on each side without having to go as high as 128k, right? Would 96k be enough? Would 80k?
Is there a "rule of thumb" or a tool that could tell me what bitrate would be required for joint stereo to achieve the same quality as 64k mono?