Amp for L7

I just dug at the actual test sheet for my amp and it actually puts out 710W mono into 4ohms, so I am definitely going to stick with it.  On kicker's website it says that if you build a vented enclosure you need to use a subsonic filter.  Does anyone know if this is really necessary, and if so where do you get one.

If you're using a ported/vented box then it's not necessarily VITAL but it might be a good idea.  It's much more important in my opinion to build a box that matches the specs. that the manufacturer provides, such as ideal volume/port length/diameter, etc.

Unfortunately there's no 100% right or wrong answer, because it's not something you would be able to notice immediately anyways.  Some people abuse their subs, and for them the subs won't last longer even with a subsonic filter.  Similarly, you can't really know for sure whether or not a shortened product life is the result of misuse/abuse by the owner, or the result of not using a subsonic filter.

Certainly if it's a sealed box design (which I'd recommend over a vented box anyways), you will not need the subsonic filter.