Jed is correct. But Boscofats asks if this is complicated to do. Here's my experience with adjusting the subwoofer level on the 950.

You've got to press AUD and then TRIM on the remote something like 8 times to change the subwoofer volume. If you press TRIM once too often or once to few times, you'll be affecting something besides the subwoofer volume. You can create a macro do the 8 TRIM button presses but with a macro the remote sends the instructions rather slowly to the 950, so you have to wait (and wait it seems) before you can increase or decrease the sub level. Maybe it can be done less slowly on some other remote than the one that comes with the 950, but on the 950's remote, it's slow.
On many other pre/pro's and receivers you only have to press a button or two on the remote, and no macro is needed, in order to adjust (without waiting) the subwoofer level.