This would be an overkill. 10 feet of such cable would have resistance of 12mohms (6mohms each way) while inductor in series with the woofer has most likely 100mohms (limiting DF to 80). 500 strands might be bad since it does not help skin effect (that starts at gauge 18 in copper at 20kHz) and causes constant current jumps from strand to strand (caused by skin effect) thru impurities (oxides) residing on the surface of each strand. What you need is gauge 10 total with about 10 insulated (gauge 20) strands twisted on on hollow tube or arranged as a flat tape so that each strand would be exposed only to magnetic field of neighboring strands.
