The "speaker level input" on a subwoofer goes into a "voltage divider network", which derives a line-level signal from the speaker-level signal. This line-level signal then goes into the subwoofer's electronics, including the gain control, low-pass frequency control, and any others, before going to the power amp section and being amplified to actually drive the woofer.
If you use the "line level input", there would be no need for the voltage divider network, but everything else would be in the signal path.
Some subwoofers have an "LFE input", which is designed to accept the LFE channel output from a processor. In this case the gain and frequency and EQ (if any) have already been set by the processor, and all that's left is for the subwoofer's amplifier section to amplify the signal and drive the woofer.
Given that the motion feedback feature is part the amplifier section, it would be active in any of the above scenarios.
Duke
If you use the "line level input", there would be no need for the voltage divider network, but everything else would be in the signal path.
Some subwoofers have an "LFE input", which is designed to accept the LFE channel output from a processor. In this case the gain and frequency and EQ (if any) have already been set by the processor, and all that's left is for the subwoofer's amplifier section to amplify the signal and drive the woofer.
Given that the motion feedback feature is part the amplifier section, it would be active in any of the above scenarios.
Duke