thats mainly in eq'ing if you pull up a 5band eq then you'll see the different freq's an you can roll of "cut" highs, lows, an mids... look up s#it on eq you'll see what i mean

MediaMurder wrote: Does anyone know a good resource for this type of thing?

A bit obvious, maybe, but have you tried the internet?

yeah, nevermind...
I found some cool resources.
Thanks guys..

http://www.amazon.com/dp/0240806255/?tag=r06fa-20

3dB is the half power point
http://en.wikipedia.org/wiki/Half_power_point.

Look up bode plots too:
http://en.wikipedia.org/wiki/Bode_plot

So much to learn.... so little time.