Speaker Replacement Help

[davo32683]

I'm considering swapping the door and rear door speakers on my 2004 Silverado. I've got the Bose system, so do I need anything special for aftermarket speakers to work? I'm keeping the factory HU, so we don't need to look into that (can't afford that right now).

 

I'm looking for a little more bass hopefully and more clarity. I'm pretty sure the backs are 4x6's. The fronts are 6.5" if I'm not mistaken.

 

Was searching around on Crutchfield and found 3 different 6.5" subs available. I wonder if one of those would work to replace the Bose sub? Just curious about that, maybe somebody will know. I wouldn't amp it any more or anything. Just thinking about experiments.