Originally Posted by Heinrich S
How is that? There is only 200 watts per channel. I would imagine only a fraction goes to the tweeter and the larger proportion goes to the woofer. You saying 400 watts?
Available doesn't mean used. In normal content, the power required for the frequencies the tweeter reproduces is about 25 percent of the power required for the rest of the audio band, so unless he plays white noise at very high levels, the tweeter will not receive high power. Ever. Because what you play doesn't have it.
I also suspect some misunderstanding that if I have a 200 watt power amp, I am feeding 200 watts to the speaker all the time. Not true. If we can agree that, all things being equal, a more powerful amp can make a speaker louder, we're halfway home. The speaker gets louder with higher voltage/more power input. That means it cannot always be receiving full power from the amp, because sometimes you turn down, and the speaker is quieter, and sometimes the content is not at full tilt, and the speaker is quieter. Actually most of the time. So when you''re listening mighty loud and the sound is 95 or 100 dB in room, you're likely using all of 5 watts or less, regardless of whether the attached amp has 10 total watts available or 1000.
And btw, as I understand it the high pass element connnected to the tweeter as part of the crossover does not burn off energy - - it'd likely need cooling fins if when biamping the tweeter element was getting 4 times the power it was actually using and converting the rest to heat. Instead the high pass presents such a high impedance to the amp below the crossover point that the amp does not make significant current (see Ohm's law) and the power delivered to the tweeter in the lower frequencies is inadequate to harm it.
Finally doubling power NEVER EVER doubles the perceived sound level. As long as the speaker stays linear (doesn't compress) doubling power adds 3 dB. That's going to sound "about one notch" louder, to most folks. Twice as loud is usually defined as 10 dB, and requires 10 times the power. Thus, for example if you're watching a movie with relatively loud dialog at 85 dB, that has explosions that use the max available headroom at 105 dB, the dialog is using 1/100 (that's right one percent) of the power that will be used for the explosions.Edited by JHAz - 2/7/13 at 8:29am