For what it's worth, I just use one of the smaller Monster devices that is both a surge protector, and a line filter. Cost $300-400.
Whole house surge protection being a better choice. You can order one online for around $200. Then get an electrician to install it for you, if you don't feel comfortable doing it yourself. Much cheaper than one installed by the electrical company and you don't have to pay extra on your utility bill.
I've always heard it's best if there is no line conditioning on the subwoofer so power supply won't be restrained when you need it. I don't think a surge protector would do any current limitation when it's drawn by the device, only when a surge enters the house from outside.
