Yep, the 1050 does have test tones for all, including the sub. However, I found the sub test signal too low to be useful. It really pounded the $@!% out of things since, to make the test signal match, I had to crank it way up. You can imagine the results when you throw an LFE at a sub cranked too high.

Best bet is a test signal DVD and the trusty Radio Shack SPL meter. Otherwise, use the internal test signals for the six, and then calibrate the sub manually while in use.