Frequency band separation techniques
Frequency band separation techniques
Hello,
I thought this subject might be an interesting one to discuss because there's more than one way to achieve band separation & it seems like the separation technique you choose would depend purely on the application (number of bands, device purpose etc). I've tried quite a few different methods now in the sdk which I'll detail if you like. I've had good results with all of them. I can see the benefits of certain methods for particular tasks, but thought it would be cool to discuss it & see what some of you guys think and have to offer on the subject. There's always the issue of cycle/memory cost as well, so that affects the method (module in the Scope paradigm) selection for particular tasks. What methods of band separation do you think are preferable & which do you prefer for given tasks? Ok, that's maybe a big question, but I think it's probably not & actually relatively simple for certain applications. Any thoughts? All input is welcome.
I thought this subject might be an interesting one to discuss because there's more than one way to achieve band separation & it seems like the separation technique you choose would depend purely on the application (number of bands, device purpose etc). I've tried quite a few different methods now in the sdk which I'll detail if you like. I've had good results with all of them. I can see the benefits of certain methods for particular tasks, but thought it would be cool to discuss it & see what some of you guys think and have to offer on the subject. There's always the issue of cycle/memory cost as well, so that affects the method (module in the Scope paradigm) selection for particular tasks. What methods of band separation do you think are preferable & which do you prefer for given tasks? Ok, that's maybe a big question, but I think it's probably not & actually relatively simple for certain applications. Any thoughts? All input is welcome.
You know, that I'm a big fan of broad seperation like I did in most of my devices, but I'm not that smart concerning alternative methods & their advantages. I remember reading something with "fir" on it recently, but I might remember wrongly. As I'm no expert in digital filters I have no idea how to implement/build fir-filters... Is it possible with sdk?
a lowpass is a mathematical technique to smoothen discrete values. quick discrete peaks are high freq. audio information.MCCY wrote:Sounds cool. Could anybody explain in easy words, what fir is, b.t.w.?
Or was "back on phase" a hidden hint once again? It's nicer to ask here than reading in wiki.
fir uses a dedicated amount of delayed signals to calculate the new values.
iir uses the technique of recursive programming to calculate the new values.
mehr oder weniger sind alles mathematische Glättungsverfahren.
Glättung entspricht sozusagen einem Lowpass Filter.
Hey, thanks for all the comments so far!
You could also use a network of LP filters (6-24dB), sync inverters & 2>1 adders to create a nice separation circuit up to a certain No' of bands. It works on the theory that if you feed 2 LP filters with the same input signal, set one to say 300Hz & the other to say 3kHz then subtract the 300Hz filter output from the 3kHz filter ouput, you create a bandpass filter with a pass band of 300Hz - 3kHz.
I haven't tried the FIR approach though. Would that not be a bit much tax on the old dsps?
I guess there's alway's the parametric eq network as well, but I haven't investigated that as far up as 31 bands or anything like GRAPH EQ.
Yes, by broad separation I take it that you mean creating crossovers using configurations of HP & LP filters? Or maybe in a HP-BP-BP-LP setup?MCCY wrote:You know, that I'm a big fan of broad seperation like I did in most of my devices
You could also use a network of LP filters (6-24dB), sync inverters & 2>1 adders to create a nice separation circuit up to a certain No' of bands. It works on the theory that if you feed 2 LP filters with the same input signal, set one to say 300Hz & the other to say 3kHz then subtract the 300Hz filter output from the 3kHz filter ouput, you create a bandpass filter with a pass band of 300Hz - 3kHz.
I haven't tried the FIR approach though. Would that not be a bit much tax on the old dsps?
I guess there's alway's the parametric eq network as well, but I haven't investigated that as far up as 31 bands or anything like GRAPH EQ.
@MCCY
its all about the phase you know . .
maybe now, with a 15 month delay,
you see my point in the funny phase discussion without emotion from a different phase position _;
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you can build your own filters or combine existing ones but dont invent the weel for a second time;
simple lowpass filter greetings
good vibes + (good vibes - 1sample) = cutofffrequency samplerate/2
its all about the phase you know . .
maybe now, with a 15 month delay,
you see my point in the funny phase discussion without emotion from a different phase position _;
---------
you can build your own filters or combine existing ones but dont invent the weel for a second time;
simple lowpass filter greetings
good vibes + (good vibes - 1sample) = cutofffrequency samplerate/2
Yeah. Spend hours on that topic.its all about the phase you know . .
Now that was my point all the time, wasn't it? In the end all is about sound I'd say.you can build your own filters or combine existing ones but dont invent the weel for a second time;
Fir seems to excede my knowledge for now (by far). From what I read here, in wiki & co. I'll have to learn quite a lot to understand those things on a more basic level... But I think best learning starts with interest
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the fir atom
The FIR atom is an enigma to me as is has no variables to configure - anyone know how to use it ? say to construct a FIR with 21 taps for example ?
Thanks
Thanks
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