The channel calibration test tones do not pass through the crossover, so testing the mains would not send anything to the sub. The subwoofer test tone, of course, is a different matter, and should yield sound. Try the following, just to cover all the bases.

• Verify connections (power to sub, interconnect from 950 to sub) - this looks to have been done
• Verify settings on back of LFM-1: adjust volume to at least 5, set power switch to either "auto" or "on", and I'd probably switch the crossover control to "bypass."
• Go to "Speaker Config" menu in 950 and verify that the speakers are set to "small" and the sub is set to "on"
• Go to "Channel Calibration" menu in 950 and try the subwoofer test tone. Be sure the master volume is set to 0 dB first, and I'd recommend putting the 950 on an empty input since 0 dB can be loud and you'll be listening to the active input before and after going into the menu.

If all of the following is done and you don't get a tone from the sub, let us know.