I'm just comparing recordings made in Notes on the 3650 and the 1945.
I found the problem though--I was selecting recording input mode on the Audio selction in settings/system which only offers a close or far recording option. If you look in Settings/personal/input/options you can choose the reocording format Hz, 8 bit, etc. from a wide range of quality settings. Mine was set on the low quality default which probably explains my problem.