if you want to convert/change/modify the values that you get from the audio amplitude you need an expression. there are many ways to do this. one of the basics expressions is called "linear". as explained here: After Effects Tutorial | Audio Keyframes - YouTube .
like the tutorial illustrates - you set the expression on the BOTH CHANNELS stopwatch. first you look for the range of the both channels amplitude - for example if you want just the kicks then look for when it's the highest and when it's the lowest (for a kick, not for all the audio) - you can use the graph editor to see the curve (select value graph, not speed graph) to find it easily. let's say its 45 and 60.
you Alt click on the stop watch of Both Channels and set this expression: linear(value, 45, 60, 50, 200) - this means that it will convert the 45 (low) value of the amplitude and the 60 (high) value of the amplitude to 50 and 200 value (but you can specify any value you want for it to convert to). after that you can pickwhip the parameter you want to be affected by this (in your case: scale) to the both channels stopwatch and there you have it.
this is another expression by the Dancing-with-Scripts-Master Dan Ebberts to deal with audio to keyframes: http://motionscript.com/design-guide/basic-audio.html - just copy the expression he typed down there to the value you want to affect, and set the parameters in the expression box on what is high and low in your audio amplitude, and then set the factor for it to multiply your value.
and here is another way:
more geeky information in here under interpolation methods:
Yes this helped exactly how I wanted! Thank you! Once I checked what frequency the kick was at, I just copied this expression:
minAudio = 0;
maxAudio = 15;
maxStretch = 2.0;
audioLev = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider");
stretch = linear(audioLev, minAudio, maxAudio, 1.0, maxStretch);
value * stretch
After I pasted it, I just plugged in my own numbers in which my kick was hitting at. So all I changed was
minAudio = 50;
maxAudio = 65;
maxStretch = 1.5;
Great! Dan is a wizard, I am just passing information through