4 XLR/TRS inputs are built-into the DR-70D. The four-channel design enables combinations of shotgun microphones, lavaliere mics, and the built-in stereo mic to be recorded individually. Channels 1 and 2 can be set to stereo input and channels 3 and 4 can be set to the built-in mics, making a variety of mic configurations possible.
MONO/DUAL MONO:Best for recording the audio of a single performer.
STEREO/DUAL STEREO:Best for recording with the built-in microphones or a stereo mic.
2MIX/DUAL 2MIX:Creates stereo files of two or more mixed inputs.
Dual Recording mode can be used to create a backup file that is simultaneously recorded at a different level to prevent clipping when levels exceed the maximum input. The second track is recorded up to 12dB lower as a safety track to prevent distortion ? if your input signal overloads, you have a backup that isn't distorted.