Danny, let me start by saying this: Any time a (properly sized) fuse blows, it's doing its job. So far, you've replaced the fuse, and the unit still works. Understand?

If the unit calls for a 1-1/2A fuse, use that. You might go to a 2, and it might or might not protect the sub amp. If reducing the bass level to keep from popping the fuse doesn't produce enough bass to make you happy, you need a different sub.

Larry