Page 7 of 7

Re: Research ... capture EQ curve

Posted: Mon Apr 02, 2018 12:44 am
by guyman
Hello Martin. Care to share this schematic wired up with the real time convolver? :D

please and thanks.

Re: Research ... capture EQ curve

Posted: Tue Apr 03, 2018 9:17 pm
by francoisreme
Hi Guys.

Martin thanks for this clean and great work !

I'm a bit confused about the convolution part. I'm sure this is maybe covered somewhere else but I can't fint any ressource on that.

I understand that you get an half spectrum from DC to almost nyquist freq (4096 bins) from the output of the FFT anlysis module.
From what I understand, we are macking a average on the squared magnitude, and we finally apply the square root juste before the output of the FFT Anlysis.

But what I can't get is the zero padding part. I mean I get the point of the zero padding because of temporal aliasing in the convolution. But I can't get how taking IFFT of an asymetrical spectrum (which gives complex temporal domain filter kernel), tacking only this IFFT real part, shifting by 1/4 of the size, and keep only the half can be equivalent to making the spectrum symetric before IFFT. I migh be one of these cool DSP hacks but I miss a few ressource to get this one !

does someone get a ressource ?

Also I re downloaded all .fsm from the realtime fft thread, I seems that Martin introduced the idea of meshed convolution in his convolution implementation in this post :
viewtopic.php?f=4&t=3879&hilit=reverb&start=20
But I really can't understand how it works ! Any of you guys got it ?

Thanks !