A few things;
"Surge protection", as portrayed here and elsewhere is largely useless. Real attempts at mitigating voltage surges, brownouts etc, do not include devices such as these.
Never plug an amplification device into UPS/surge protection devices,... due to potential current limiting effects. Plug them into the wall.
Most "power strips" don't offer anything but switching capability. Any surge protection is laughable,....and if it actually possesses adequate surge protection, your subs don't need it anyway.
Never use single insulated, "zip cord" style extension cords. Double insulated is the way to go. Now, only use extension cords if nessesary,...and if you do use one, use a quality with quality cord caps.
The APC products discussed by the OP are not reliable. I've purchased them for multiple PC workstations for my kids. They were used in several hundred HVAC control cabinets at Lucas Oil Stadium, and a vast majority of them encountered problems. Even when new, they exhibited problematic behavior upon their first power outage and subsequent usage. I've experienced the same issue with half of the small APC models I bought. Their somewhat larger products perform much better.
Thanks and good luck