Originally Posted by rick240
Everyone talks about how speakers need to be able to deal with dynamic peaks in movies and music.
Good set of questions.
I have read here that speakers should handle anywhere from 15 - 25 db peaks.
Something like that. 20 dB is commonly cited number and based on years of analysis of real world music, its a pretty good number.
Are there frequency ranges that these peaks are most commonly in?
I find that to be unpredictable. People write, perform, mix and master music in accordance with their preferences. Digital media can handle just about anything that someone can come up with.
What I can say for sure is that if the peak is in a low frequency band then it needs to be more intense for a desired perception of intensity because the ear's sensitivity is so much less in those ranges. I suspect that the 25 dB number may arise in situations involveing bass for this reason.
i.e. do all drivers need to be able to deal with the power that such a peak would represent?
I think so.
It is far easier to build highly efficient, high SPL high frequency speaker drivers than low frequency high SPL speaker drivers.
The efficiency of speakers for low frequencies is tightly constrained by some pretty rigid and oppressive laws of physics. Basically, size, efficiency, and low frequency extension are tightly connected and if you up one, you are forced to cut another. At medium and high frequencies the same physical laws are in force, but because the frequency is so much higher, the constraints are far less oppressive.
One of the evolutionary changes in loudspeaker system construction over the years has been the availability and use of drivers for high and low frequencies that have much larger power handling and SPL generating capabilities.
In the days of analog media subwoofers were relatively rare because they could cause feedback problems and really didn't have that much to do. Those kinds of frequencies weren't usually coming off of analog media in large quantities. They can't be recorded cleanly. Both analog tape and vinyl have severe limitations at very low frequencies.
In the days of analog media the dynamic range of the media significantly limited the low and high frequency dynamics that could be cleanly recorded and played back.
Digital media can generally handle all audible (and many inaudible ones as well!) signals with equal intensity, equally well.
The current problems with hypercompression are enabled by the more ideal characteristics of digital media.