It may be tempting to read the schematic like a water drainage diagram (?) but no, the capacitor still has an influence to some degree.
I think you have Hz and kHz mixed up somehow.
The resistor causes a zero with a corner frequency of approximately 1.6 kHz, while the cut-off frequency of the low-pass formed by the 2.3 mH inductor, 100 uF capacitor and woofer impedance is of the order of 350 Hz. I think the roll-off of the filter and woofer together was a bit steeper than intended above 1.6 kHz and the resistor was added to solve that. As a side effect, it also damps the low-pass a bit.
The resistor causes a zero with a corner frequency of approximately 1.6 kHz, while the cut-off frequency of the low-pass formed by the 2.3 mH inductor, 100 uF capacitor and woofer impedance is of the order of 350 Hz. I think the roll-off of the filter and woofer together was a bit steeper than intended above 1.6 kHz and the resistor was added to solve that. As a side effect, it also damps the low-pass a bit.