Dear aaronji
Firstly, thanks for your help.
For sure, that's page 32 of the .pdf on the Marantz site is very clear.
And here are some general guidelines from the sound professionals spsb 6's manual:
"For louder, bassier situations, try higher settings; for smaller, quieter situations, use lower settings. If the venue has bad acoustics, use higher settings; for venues with better acoustics, use lower settings. If you are using cardioids, use lower settings; for omnidirectional mics, use higher settings (cardioids reduce bass somewhat when compared to omni’s as a function of their more directional pickup pattern)."
"If you are going to be recording loud sounds (rock concerts, full orchestras, close miked instruments, etc.), it is suggested that you use the “line in” jack of your recorder. This will produce excellent results with these types of sources. Rule of thumb is to always try the line input first. If you can get levels strong enough to use the line input-use it, as you will generally get cleaner recordings using the line input."
I will setting the switches to higher numbers to remove more bass from the recording.
I will use "Line in"
Yours sincerely
Robert