So, if i understand well ?)
Linear phase is not so much what we need, but a linear phase with FIR (if symmetric) (or maybe IIR if possible) will do the same group delay for all frequency ?
If we have to do a multiband, it's really better to have the same group delay, if it's a filter that exclude some frequency, it's not so much needed, but it will more sound like "boing", like in a spring reverb, if there's different delay by frequency ?
Meaning that the transiant will not sound the same ? (which could be desired some time ?)
FIR Filter had some advantage in the past, but do they have any now ?
Seams that using IIR with some modification to make them group delay,
we get something that is more efficient and optimized in any case ?
Like here :
viewtopic.php?f=4&t=8081&p=115410&hilit=group+delay#p115410and here :
viewtopic.php?f=2&t=2822&p=15319&hilit=MultiBandSplitter#p15319Maybe the average filter could continue to have some advantage, because it need less calculation ?
(But from what i try it's really hard or impossible to make an average filter that have real time configurable cutoff..)
I was planning to try a larger size FIR, but apart from liking to try it, seams that there's no real usage ?
(Wanted to try if this way to address the memory could be a little faster : )
- Code: Select all
//4sample loop//
movaps xmm1,a;
shufps xmm0,xmm1,0;
shufps xmm0,xmm1,152;
movaps a,xmm0;
//index & write//
mov eax,x[0];
add eax,-16;
and eax,1023;
mov x[0],eax;
movaps mem[eax],xmm1;
//read//
add eax,64;
and eax,1023;
movaps xmm2,mem[eax];
add eax,64;
and eax,1023;
movaps xmm3,mem[eax];
//...etc
Thanks for all the precision and all those treasury in the forum !
Seams that when we are not Flowstoner, understanding dsp filters is a breaking head and a crazy voyage !
Trying to understand very simple principle, we are facing incomprehensible formula where it it's only a feedback loop..
And we get fastly the best filters if we search a little on the forum !
I don't even know why i do some filter
!)
Maybe it's to more understand what's happen for the signal ?
Maybe sometime i like to have some simplified one ?
(only one coefficient for all, not so much care about the curve, experimental non linear think... ...)