Is there a average MB of storage per minute when recording, that we can use to calculate free space required?

This will vary depending upon the file format you recording in. <br> <br>We are commonly asked this for CallCapture, which records (typically) to Microsoft GSM (a variant of GSM 6.10 format) format: <br> <br>60 Kb/min of audio <br>Some things to consider for this are: <br>On a 4.7 Gb DVD, this means: <br>78333 minutes <br>1305 hours <br>56 hours of non-stop recording on 23 channels <br> <br>If you are using the standard WAV format, it is (approximately) 14 times larger than the calculations above.