Here are the "real" OSHA numbers for continuous noise, not random, like music, exposure. 85 dB levels with music is far from continuous and is more than fine. My "ear" says the Fletcher Munstrom (spelling) flattens out at about 80dB, where the low end seems linear. The human ear is lousy below about 80 dB for linearity of broad spectrum sounds. We hear around 1-4 KHz at 75 dB OK. That's as nature intended. True, you can "flatten" the sound by EQing to 75dB (remember loudness controls), just don't turn it up much with that EQ active!
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9735
TABLE G-16 - PERMISSIBLE NOISE EXPOSURES (1)
______________________________________________________________
|
Duration per day, hours | Sound level dBA slow response
____________________________|_________________________________
|
8...........................| 90
6...........................| 92
4...........................| 95
3...........................| 97
2...........................| 100
1 1/2 ......................| 102
1...........................| 105
1/2 ........................| 110
1/4 or less................| 115
And, Go here;
http://www.stereophile.com/content/dynaudio-confidence-c4-loudspeaker-measurements
Most of a speakers "power" is dissipated at the lower frequencies below 200 Hz and more than 4/5th total isn't uncommon. Here, the graph of C4's clearly shows significant phase departures from "zero" that approach +30 to -50 degrees. It isn't near zero till about 200 Hz in this speaker. Since the majority of the load is mostly reactive below 200 Hz this is a terrible "resistive" load per your conclusion. It is NOT a resistive filament. No where near. It does produce a very reactive signature to the majority of the signal power being applied. This is what your amplifier is fighting against. The numbers at the frequency of the power dissipation peaks show that this isn't as bright of an idea as lighting a light bulb.
As far as the jackhammer example, It's amazing that a device that is intended to crush rocks loses just 1 watt to sound. Sound SPL at a given volume has a measurable power in air that is always the same no matter what produces it. 1KHz at 100 dB SPL is ALWAYS the same power level in-air. It doesn't know who it's mommy is. The energy "used" to launch it varies tremendously in wasted effort, true. The SPL of a jackhammer's frequency range is pretty low and at a pretty high 120 dB SPL so it is amazing that it has a 1 watt sound launch energy value. And the actual "sound" efficiency would be the power going in to make the SPL level coming out (here we'd ignore the jackhammers real job and look at it as a noise maker) right?. How much power is going into a jackhammer relative to the lost energy due to the "sound" escaping from the intended process? Most of the energy is going into the rocks, so it's a pretty lousy speaker for making 120 dB of noise...as it should be.
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9735
TABLE G-16 - PERMISSIBLE NOISE EXPOSURES (1)
______________________________________________________________
|
Duration per day, hours | Sound level dBA slow response
____________________________|_________________________________
|
8...........................| 90
6...........................| 92
4...........................| 95
3...........................| 97
2...........................| 100
1 1/2 ......................| 102
1...........................| 105
1/2 ........................| 110
1/4 or less................| 115
And, Go here;
http://www.stereophile.com/content/dynaudio-confidence-c4-loudspeaker-measurements
Most of a speakers "power" is dissipated at the lower frequencies below 200 Hz and more than 4/5th total isn't uncommon. Here, the graph of C4's clearly shows significant phase departures from "zero" that approach +30 to -50 degrees. It isn't near zero till about 200 Hz in this speaker. Since the majority of the load is mostly reactive below 200 Hz this is a terrible "resistive" load per your conclusion. It is NOT a resistive filament. No where near. It does produce a very reactive signature to the majority of the signal power being applied. This is what your amplifier is fighting against. The numbers at the frequency of the power dissipation peaks show that this isn't as bright of an idea as lighting a light bulb.
As far as the jackhammer example, It's amazing that a device that is intended to crush rocks loses just 1 watt to sound. Sound SPL at a given volume has a measurable power in air that is always the same no matter what produces it. 1KHz at 100 dB SPL is ALWAYS the same power level in-air. It doesn't know who it's mommy is. The energy "used" to launch it varies tremendously in wasted effort, true. The SPL of a jackhammer's frequency range is pretty low and at a pretty high 120 dB SPL so it is amazing that it has a 1 watt sound launch energy value. And the actual "sound" efficiency would be the power going in to make the SPL level coming out (here we'd ignore the jackhammers real job and look at it as a noise maker) right?. How much power is going into a jackhammer relative to the lost energy due to the "sound" escaping from the intended process? Most of the energy is going into the rocks, so it's a pretty lousy speaker for making 120 dB of noise...as it should be.