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BruteFir integration
#31
[attachment=1887 Wrote:bitlab pid='27068' dateline='1604863684']@Coustard I can garantee nothing, we can only do our best to make it as accurate as possible  Big Grin
I tried the BW as in octaves (dived by 2), but that was clearly not a match.
Also if you take look at the AutoEQ HD800s example, you see a difference between APO and EqFap.

We made the transfer function from Q to bw not part of the filter library but of moOde it self.
In this way we can easy and fast update the transfer function if we find a better solution.

For completeness hereby both transfers plotted (BW A = yours, and current BW =0.5/Q):


If you have any doubts about the correctnees just let me know.

No doubts! I've attached an REW plot of my measured EqFa4p curve (+10 at 1k, BW 0.5) vs an REW generic band of +10 at 1k Q1 which shows pretty much the same relationship as your curve for EqualizerAPO so it looks like my comparison with Logic's Eq is unhelpful and eyeballing my measurements again and doing a bit of basic Q maths I'm not sure that Logic's Q is technically 'correct'. 

Anyway, it's looking like a really great addition to moOde. Apologies for the intervention - carry on...


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#32
(10-30-2020, 06:31 PM)jijopujolo Wrote:
(10-08-2020, 07:06 PM)bitlab Wrote: The CAPS project EqFA4p filters makes use of a bw (bandwitdh) parameter instead of the Q factor.
In the past a few asked question about the exact meaning of bw, but I didn't see the answer.
Did anybody make progress on that 


I may be completely wrong, but I seem to remember reading on some audio forum about the bw parameter in EqFA4p simply being the bandwidth in octaves (there are online converters for converting Q factor to bandwidth in octaves). Is that possible?

PS: @bitlab thanks for your great work!

 I read as well that it is the bandwidth in octaves. It may be off by a factor 2 or 1/2 but that’s it.
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#33
(11-08-2020, 05:56 PM)bitlab Wrote: @Coustard I know that bandwidth calculator and few weeks ago. And I even tried that math to see if that comes close:
I wrote a script where you can provide the fc and Q and it will calculate the rest.

Code:
fc=50.00Hz Q=1.00 bw=1.00 fl=30.9 fh=80.9 fd=50 bw_eqfa=0.50 N=1.388
fc=1000.00Hz Q=16.00 bw=0.06 fl=969.2 fh=1031.7 fd=62 bw_eqfa=0.03 N=0.090
fc=1000.00Hz Q=8.00 bw=0.12 fl=939.5 fh=1064.5 fd=125 bw_eqfa=0.06 N=0.180
fc=1000.00Hz Q=4.00 bw=0.25 fl=882.8 fh=1132.8 fd=250 bw_eqfa=0.12 N=0.360
fc=1000.00Hz Q=2.00 bw=0.50 fl=780.8 fh=1280.8 fd=500 bw_eqfa=0.25 N=0.714
fc=1000.00Hz Q=1.00 bw=1.00 fl=618.0 fh=1618.0 fd=1000 bw_eqfa=0.50 N=1.388
fc=1000.00Hz Q=0.50 bw=2.00 fl=414.2 fh=2414.2 fd=2000 bw_eqfa=1.00 N=2.543
fc=1000.00Hz Q=0.25 bw=4.00 fl=236.1 fh=4236.1 fd=4000 bw_eqfa=2.00 N=4.165
fc=1000.00Hz Q=0.12 bw=8.00 fl=123.1 fh=8123.1 fd=8000 bw_eqfa=4.00 N=6.044

This is fantastic. Did you double check also on other frequencies? (Oh, I see you already gave fc=50 and 1000...)
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