Notwithstanding the seemingly naive questions that I've posed, I do have a good understanding of many of the concepts that we've been discussing. After all, I do have a degree in electrical engineering (though that was a long, long time ago and I did not pursue a career in that field). That and I've been playing bass for 40+ years. You are 100% correct that, in most cases, the information available is not clear or complete enough.
The most frustrating challenge for a consumer is that each manufacturers presents information in a way that highlights their strengths and masks their weaknesses -- I think we call that marketing. When I reach out to the collective knowledge of TalkBass, my goal is to [hopefully] gather all the available data and compare the elements that are most relevant to the solution that I am investigating.
I bought a Hartke LX5500 head and a single HD112 to go with it -- They are very well matched. The amp at 8-ohms puts out 330w into a cabinet rated for 300w. It took one outdoor jam to determine that a single 12" cabinet doesn't move enough air for me, so I added a second cabinet. Now, a pair of HD112's set for 8-ohms in parallel loading the amp with 4-ohms resulted in 500w of power into a 600w speaker array. That was plenty of rig for my gigs.
I replaced the Hartke LX5500 with a Mesa Boogie Subway TT800 because I was looking for a different tonal pallet; not more power. Ergo it is a retrofit to my existing gear. Because I know that two 12" cabinets and 500 watts of power is more than sufficient for my needs, I am not concerned about damaging my existing speakers.
Here is the rub... at 500w, the LX5500 seemed louder than the TT800.
