If I were to build a sealed speaker with a closed box Qtc=0.707, F3=150hz and wanted to extend the responce down one octave to 75hz using a shelf filter function in MiniDSP how would you calculate this?
I know how to produce a biquad filter using a LT but wanted to know how to calculate a simple shelf to extend the responce by one or maybe two octaves with out altering the Qtc?
Would the following be correct for one octave;
FC= SQRT (75*150) = 106hz?
Gain=12dB
Q=0.707
for two octaves;
FC= SQRT (37.5*150) = 75hz
Gain=24dB
Q=0.707
for 1.5 octave;
FC= SQRT (56.25*150) = 91.8hz
Gain=18dB
Q=0.707
I know how to produce a biquad filter using a LT but wanted to know how to calculate a simple shelf to extend the responce by one or maybe two octaves with out altering the Qtc?
Would the following be correct for one octave;
FC= SQRT (75*150) = 106hz?
Gain=12dB
Q=0.707
for two octaves;
FC= SQRT (37.5*150) = 75hz
Gain=24dB
Q=0.707
for 1.5 octave;
FC= SQRT (56.25*150) = 91.8hz
Gain=18dB
Q=0.707
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