In an ideal world, we'd never run out of gas, milk, or power in our power amplifiers. Unfortunately, unlimited gas, milk, or power does not come cheap. Depending on our wallets,we have to balance between $$ and headroom (or supply). While we could go out and buy 50 gallons of milk right now, but more than likely 48 and a half of those will be going to waste. A lot of times audio power is the same way. Basically, I'm saying that if you have unlimited funds for a PA system, go out and buy as many 50,000 watt amplifiers as you need. This will ensure that you never run out of power. Of course, this is 100% total overkill!

You see, if you are playing your music at 96db (Not as loud as a band, but definitely loud enough to piss off the neighbors) with just one speaker with a sensitivity of 90dB @ 1 watt, you need to double your wattage to get up to 93dB. So we now have 2 watts. We need to double the wattage again to get to 96dB. So it looks like we need 4 watts to hit 96dB with our hypothetical speaker.

Back to the headroom concept. If a person knew they would never play louder than 96dB, it would be an easy decision. They could stick with the 4 watt system and piss the neighbors off all day long. However, especially with PA systems or studio monitors, there is always that chance that we'll need a few extra dB of power. Maybe there is just one huge bass hit just one time. If we don't have enough power, we'll distort for sure, but we may have way bigger problems (read on).

Because people always want to have plenty of power and don't want to chance running out, they buy 2,000 watt power amps. I can tell you right now that 2,000 watt power amps probably won't sound noticeably louder than 1,000 watt power amps. Why? One, because of the way they are used. You will get an extra 3dB of headroom from doubling your power to 2,000 watts, but that's only a 3db increase. Read on. You'll see that a compressor or limiter can do a lot more good.

If you are a using a 2,000 watt amplifier, let's see how loud we can expect to go with our one speaker with a 90dB sensitivity.

1 watt = 90dB

2 watt = 93dB

4 watt = 96dB

8 watt = 99dB

16 watt = 102dB

32 watt = 105dB

64 watt = 108dB

128 watt = 111dB

256 watts = 114dB

512 watts = 117dB

1024 watts = 120dB

2048 watts = 123dB

Well, it looks like our 2,000 watt power amplifier will handle a tad under 123dB. Well guess what! My research tells me that 120dB (which is an RMS type of sound) is the volume of a “Painfully loud jet plane” .....AND WE WENT AHEAD ADDED 3 MORE dB!! If it we just one hit of a snare drum hitting 123dB and then the rest of the band was still sitting at 117dB or so, the extra headroom would be almost meaningless. Of course, jumping from 1,000 watts to 2,000 watts certain will cost you some $$.