mr_fender
Axe-Master
The cutoff frequency of most filters is at the -3 dB point in the curve. A 6 dB/octave (aka 1st order) filter will roll off an additional 6 dB signal each octave beyond the cutoff frequency. A 12 dB/octave filter (aka 2nd order) would roll off 12 dB per octave.
For example, a 6 dB/octave high pass (low cut) filter set at 1 kHz would give you:
above 1 kHz = pretty much flat.
1 kHz = -3 dB
500 Hz = -9 dB
250 Hz = -15 dB
125 Hz = -21 dB
62.5 Hz = -27 dB
31.25 Hz = -33 dB
a 12 dB/octave high pass (low cut) filter set at 1 kHz would give you:
above 1 kHz = pretty much flat.
1 kHz = -3 dB
500 Hz = -15 dB
250 Hz = -27 dB
125 Hz = -39 dB
62.5 Hz = -51 dB
31.25 Hz = -63 dB
As you can see the 12 dB/octave filter drops off much faster even though they are both set to the same cutoff frequency.
For example, a 6 dB/octave high pass (low cut) filter set at 1 kHz would give you:
above 1 kHz = pretty much flat.
1 kHz = -3 dB
500 Hz = -9 dB
250 Hz = -15 dB
125 Hz = -21 dB
62.5 Hz = -27 dB
31.25 Hz = -33 dB
a 12 dB/octave high pass (low cut) filter set at 1 kHz would give you:
above 1 kHz = pretty much flat.
1 kHz = -3 dB
500 Hz = -15 dB
250 Hz = -27 dB
125 Hz = -39 dB
62.5 Hz = -51 dB
31.25 Hz = -63 dB
As you can see the 12 dB/octave filter drops off much faster even though they are both set to the same cutoff frequency.