How loud is loud, What DB is actually loud?

I dont know who the nutter is who had 135db in the car, but I suspect the figure is wrong. More like 95db... Or he is deaf or dead.

I seem to remember the space shuttle taking off is 135db several miles away!

A quad will not get you rocking. Maybe a big sound lab could if you like ESLs. A big magnepan if you like that ESL sound will get you closer and will be cheaper. But you will need a lot of power to keep it controlled. ICE power will do it for reasonable money.

Real men (and real women for that matter) listen at no less than 120 db, for hours. It may seem loud at first, but don't worry, after a few months it won't, and, as a side benefit, neither will anything else. But on a serious note, if you want volume try either (a) horns - for more than one person and mid field or (b) large studio monitors and near field listening. The efficiency of the horns will do away with a need for a lot of power - try to find something with a horn loaded bass as well as the mid and high.

chadeffect, 135db in a car is pretty easy to do with subwoofers. i use to compete with my car about 9 years ago and only had 1 12" subwoofer and would score 136db any day. these competitions are bass only, and usually people use simple test tones to hit one frequency. there are vehicles now that score well over 170db in these competitions.

85db at 1 watt at 1 meter 1 meter is far inside a car...
88db at 2 watts
91db at 4 watts
94db at 8 watts
97db at 16 watts
100db at 32 watts
103db at 64 watts
106db at 128 watts
109db at 256 watts and so on.
Imagine what it takes to get to 170db if you keep doubling your power to gain a measly 3db? You need to gain about 10db to double the perceived volume. Even with 102db speakers (which are rare), it takes more wattage than any amp I've seen to get 170db. I imagine that it sounds pretty crummy and distorted at those levels.