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I understand IIR(biquad) filter changes gain and phase
all pass filter doesnt change amplutude, but phase changed.
That’s correct.
FIR(Finite impulse Response)filter, amplitude changes, but phase does not change.
with higher tap, create long delay.
That is not correct. A FIR filter can also change phase. (The FIR filter type you are describing is a “linear phase” filter which is subset of what FIR filters can do.) Take a look at the following guide; especially section 7.
I imported csv file into Symetrix, it looks like bunch of PEQ collection(IIR filter)
If the FIR filter response looks like a collection of PEQ’s, that is probably because you have used some PEQ’s on the “FIR Magnitude Adjust” tab, to make the FIR filter. The responses of all five “FIR..” tabs are combined to make the FIR filter. Please take a look at the two tutorials I mentioned in my first message (above).
Here is an example of a .._summary.txt file. It lists the filters from the “IIR Filters” tab, and basic information about the FIR filter file (which is saved separately).
Filename: /Users/<username>/Downloads/FIRfilter__SUMMARY.txt
Project: (none)
FIR Designer 2 version: 4.0.1
PROCESSOR SETTINGS
Sampling Rate: 48000 Hz
Gain: 0.000 dB
Flip Polarity / Invert: No
GPD Tab Delay: 0 samples, 0.000 milliseconds
IIR (Generic)
HPF_BUTTERWORTH, 100 Hz, Order 2, ENABLED
b0:0.9907866979404248 b1:-1.9815733958808497 b2:0.9907866979404248
a0:1.0000000000000000 a1:-1.9814885091445693 a2:0.9816582826171302
BAND_PASS, 364.529 Hz, BW 2.000 (Q 0.667), -6.162 dB, ENABLED
b0:0.9753337038790250 b1:-1.9007342759081824 b2:0.9275665093063239
a0:1.0000000000000000 a1:-1.9007342759081824 a2:0.9029002131853491
BAND_PASS, 3122.277 Hz, BW 0.863 (Q 1.647), -5.312 dB, ENABLED
b0:0.9340057741878747 b1:-1.5705317765303994 b2:0.7774914181148489
a0:1.0000000000000000 a1:-1.5705317765303994 a2:0.7114971923027236
HIGH_SHELF, 8384.027 Hz, BW 1.900 (Q 0.707), 3.612 dB, ENABLED
b0:1.2973957851235292 b1:-0.7856595921197735 b2:0.1733106061768412
a0:1.0000000000000000 a1:-0.4018695414139699 a2:0.0869163405945669
FIR FILTER
Sampling Rate: 48000 Hz
Filename: /Users/<username>/Downloads/FIRfilter.fdt
Length: 400 samples, 8.333 milliseconds
Delay: 200 samples, 4.167 milliseconds