Just playing around with the new biquad feature I created an eq-filter in REW (via "Save filter coefficients to file") that internaly looks like this:
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biquad1,
b0=0.9943567038075235,
b1=-1.6327458324854636,
b2=0.8909757879999204,
a1=1.6327458324854636,
a2=-0.8853324918074439,
biquad2,
b0=1.0328284933817395,
b1=-1.1995795240888156,
b2=0.7506009869239016,
a1=1.1995795240888156,
a2=-0.7834294803056412,
biquad3,
b0=0.9510455308562255,
b1=-0.5452662714257583,
b2=0.6574843715253804,
a1=0.5452662714257583,
a2=-0.6085299023816059,
biquad4,
b0=0.9477953187195922,
b1=0.0041613859646633,
b2=0.5660469224210707,
a1=-0.0041613859646633,
a2=-0.5138422411406631,
biquad5,
b0=1.0,
b1=0.0,
b2=0.0,
a1=0.0,
a2=0.0,
biquad6,
b0=1.0,
b1=0.0,
b2=0.0,
a1=0.0,
a2=0.0
--------------------------------------------------------------
This filter loaded into DSP-Studio -> PEQ to my ears sounds equal or better than the equivalent filter settings that I used to enter by hand:
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Room EQ V5.20.5
Dated: 23.03.2022 18:28:28
Notes:
Equaliser: miniDSP
links eq average + biquad2
Filter 1: ON PK Fc 4000 Hz Gain -0.90 dB Q 4.329
Filter 2: ON PK Fc 6364 Hz Gain 2.30 dB Q 2.669
Filter 3: ON PK Fc 9358 Hz Gain -2.50 dB Q 2.232
Filter 4: ON PK Fc 12021 Hz Gain -2.10 dB Q 1.757
Filter 5: ON None
Filter 6: ON None
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So far so good. My questions to the specialists here in this forum:
1) Is this a valid approach to use this feature?
2) Is there a maximum number of biquads to use?
3) I found no way to specify a channel (left/right) so I averaged R+L measurements in REW and created the filter for this
Best regards and thanks in advance for any words of wisdom