i need to set the ratio, right? i guess something aggresive like 20:1 will compress my burst of claps.
Yes, you need to set the ratio. The higher the ratio, the more aggressively the compressor reduces signal that rises above the threshold.
is it necessary to use the soft knee limiter if you are changing the variables/threshold/ratio? the preset doesn't seem necessary if i am inputing my own values. maybe i'm wrong though.
The presets are just that - presets. Specifying your own settings overrides the presets. In general, the presets are a nice starting point, but I've always tweaked the settings for my own purposes. Note you can create your own, custom presets, if you wish.
should i need to mess with the graph if i input my own values?
The graph is just a visual representation of the numeric values. You can adjust the graph and the app will change the numeric values accordingly, or you can adjust the numeric values and the app will change the graph.
the peak of the music is generally around -10dB except of one "sing-a-long" spot that reaches -5.49. is it possible to set the threshold @ -10dB? i guess i'll have to try it and figure out.
You can set the threshold to whatever value you wish. In this instance, it may make sense to set the threshold to -10 dB and apply to the whole value. Alternatively, it may make sense to apply the -10 dB threshold to the WAV both before and after the "sing-along" spot, and then independently apply a compression with a different threshold (-5.49 dB) to just the "sing-along" spot.
in the advance settings there is a choice of: peak or average volume (something like that). the default setting has average volume selected. wouldn't i want to select peak or am i looking at this backwards?
I don't recall this setting, but I'd set it to peak. Maybe try average as well, to see which you like, but I think peak is what you want in this instance.