In my quest to learn ever more about the technical side of audio, I'm trying to enlighten myself more so on the aspect of a '3dB down point'.
As a way to keep my thoughts coherent and to keep a running list of questions and answers that I've gone over in my head, I've written up a document. Yes, I'm a nerd, I accept that.
This is what I have so far, perhaps someone on here would be able to assist me in filling it out more? Or perhaps correct any misconceptions that I might have encountered?
3db Down Point
The point at which a speakers output is 3 dB down from a normal point (0dB).
From this web site: http://recording.songstuff.com/articles.php?selected=54
It is worth noting that the circuitry used to implement filters is not ideal. This means that the gain does not suddenly change from 0 dB to -18 dB as the frequency crosses the threshold, the gain change is progressive. In fact the quoted cut off frequency is the frequency at which the gain reduction is already 3dB below the input amplitude. This point is also referred to as the 3dB Down Point.
When talking about HP and LP filters, it is talking about the frequency at which point those filters are actively filtering.
Many times you create a notch in a filter, a 3dB notch. It