I've been gone from Sherwood for over 2 years and do not know which subwoofer target they load into the R-972. Eugene Chavez, Sherwood's tech guru, should be able to answer the question and have the target curves. His telephone is (714) 739-2000. If he doesn't have the curves, please send me a request at stereojeff at gmail dot com and I will send them. Once you have the curves, load one, only, to a USB stick, insert into the R-972 and follow the instructions. It takes less than a minute to load the file. Once the file is loaded, it is immediately available for playback. You do not need a new calibration.
Jeff