Optimizing Sound Systems for Varied Frequencies: Amplify or Dampen?

[Mike77]

Because the sensitivity of the human ear varies over the audio spectrum, how do many sound systems handle very high frequencies and very low frequencies, respectively, to compensate?

1. amplify; do nothing to
2. dampen; dampen
3. amplify; dampen
4. dampen; amplify
5. amplify; amplify
6. do nothing to; amplify
7. dampen; do nothing to
8. Sound systems do nothing to compensate.
9. do nothing to; dampen

HELP!

 

[cepheid]

It's kind of a vague question. I'm not sure, but I think that the sensitivity probably peaks somewhere in the middle of the audible frequency range, and then falls off as you go to both higher and lower frequencies. So, IF that is true, and if "very high frequencies" and "very low frequencies" refer to the two extreme ends of the range of human hearing, then the sensible thing to do would seem to be to amplify both to make up for the lowered sensitivity at either end.

On the other hand, if "very high" and "very low" refer to frequencies that are beyond the range of human hearing in the first place, then the sensible thing to do would be to do nothing.

This answer is a complete guess based on what I think is common sense. I have no idea what "sound systems" do in reality. (The answer is probably: it depends on the sound system and its application).

 

[Mike77]

it was correct! thanks!

 

[cepheid]

Heh, ok. Which one was correct? "Amplify both" or "Do nothing?"

I found this article backing up some of my wild suppositions:

http://en.wikipedia.org/wiki/Equal-loudness_contours

As you can see from the plot of "equal loudness" contours, at the two ends of the spectrum, a larger sound pressure level is required in order to produce the same "loudness." In the middle, a much lower sound pressure produces the same perceived loudness (because the human ear is more sensitive there). So this curve basically looks like an inversion of what the sensitivity curve must look like.

EDIT: Although there seems to be a dip in the sensitivity at around 10 kHz (which appears as a peak on this graph). Interesting.