I have been doing some reading on filters, mainly low pass, high pass and band pass. No real reason for this, just learning the basic's. Alot of what i have read, indicates that the filter is characterised at the -3db point.
So my question is, why is the value 3 db chosen? is it just a random figure that was chosen (a bit like 10 - 90% for rise times on a scope) or is there a technical reason that it has to be 3db?
So my question is, why is the value 3 db chosen? is it just a random figure that was chosen (a bit like 10 - 90% for rise times on a scope) or is there a technical reason that it has to be 3db?