Tell you what... come on over to my house and let me demonstrate a nice 2K tone through my 5.25" Dynaudio MW150 with 150 watts for a couple of minutes and we'll see if your hearing is still 100%...
The only things the OP might want to pay attention to from the post above are the sentences "...how close to the speaker you are" and "it is all about the SPL output of the box and woofers."
When someone says that they're running their driver with 200 watts, it means that the amplifier that is hooked up to the driver is rated at (or able to deliver) 200 watts of power. It certainly does not mean that 200 watts are flowing through the driver at all times... that would be *very* loud... especially through a tweeter.
Ferinstance... here is my system in my car:
Dynaudio 220 set hooked to a JL Audio 300/2 (150 x 2)
JL Audio 13W3v2 sub hooked to a JL Audio 500/1 (500 x 1)
800 total watts, but I bet that most days, the system doesn't even go over 50 watts as I don't listen very loudly.
The SPL output of a driver given a certain power input is a relatively simple calculation. Most driver manufacturers will give you some reference level at one watt, one meter from the driver. If they don't, they're lying. If they quote the level at 1/2 meter, it will be 3 dB higher than at 1 meter. If they quote at some voltage, you have to correct the voltage for the impedance of the driver as the impedance will affect how much power is actually getting to the driver. Most drivers rate between 80 (pretty low) and 92 (relatively high) dB at one watt at one meter.
The calculation for dB gain for any power level is:
10 X log(NewPowerInWatts/OriginalPowerInWatts)
So... moving from 10 watts to 40 watts = 10 x log(40/10) = 6 dB
A typical driver that puts out 90 dB at one watt at one meter driven with 200 watts will be putting out:
90 + (10 * log(200/1))
Which works out to 113 dB at
one meter. OSHA sez that you shouldn't be exposed to that SPL for more than 1/2 hour per day to avoid hearing loss.
Occupational noise exposure. - 1910.95
To the OP... yes, typically more wattage means more volume, but you're not running it wide open all of the time. And the calculation above will tell you how much louder it is when you put more power to the driver. Remember:
Double the power = 3 dB
To
sound twice as loud = 10 dB
The funny thing is that moving from 1 watt to 2 watts is a 3 dB increase... and moving from 1000 watts to 2000 watts is also a 3 dB increase (assuming that your driver can actually handle 2000 watts). It's a game of diminishing returns.