How loud is loud, What DB is actually loud?

more to it then it's sensitivity :) Some of the best sounding speakers are in the 80-90db efficiency area

I think it depends on the person on what DB is loud. I prefer loud music.... & movies my brother doesn't like it anywhere close to as loud as I like it. Never put a SPL meter to my stereo to know how loud it is.... did years ago in my car audio days.... 135-140db is all I would do since it was a SQ setup

I never sat it it at full volume.... this was back almost 20yrs ago that I was into car audio a lot. Adcom amps (which I still have), Denon CD player.... etc.. I wanted a Mcintosh amp but they were just so expensive..... out of my budget so I stuck with Adcom. I then tried Adcom at home.... their car stuff is or I guess was a lot better

It really isn't difficult to get 140+ in a car but yea, totally stupid to sit in it when hitting those numbers. I use to work at a home/car audio shop.

Those 170db systems I think use multiple 5-10K watt amps... with a wall of subs. Doesn't adding a 2nd driver add 3db if the power stays the same? Been so long I forget. But if 100w does 100db with a single 12 then that same 100w going into a pair of 12's would equal 103db? Dam it's been to long.........

With the proper amp you can make ineffecient amps play loud

yea, I would think if you double the cone area & also double the power you would get a 6db gain vs a just increasing the power.

If each speaker is getting 50w I would think it would move more air then a single driver with 100w.

No clue with the focal stuff..... I have had really good luck with Image dynamics subs. They are excellent for SQ & do not require lots of power or a big heavy box. Great stuff........