The early entry of instruments in a Render seems to be a persistant problem to many (including myself). If it sounds right when you Play a BIAB song, a Render should capture that identically. If it does not, you may want to try a real time record using the 'R Aud' button. This will create a Wav file of everything you hear as it plays. Another workaround would be to use RealBand.

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