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Parametric Equalizer

Posted: Mon Jul 22, 2013 12:18 am
by The Handle
I made an equalizer that separates frequencies into three ranges. This was done by feeding the input sound into three different chains: one with a low-pass filter, one with a high-pass filter fed into a low-pass filter, and one with a high-pass filter. Each chain has an amplifier after it to increase/decrease the volume of each range. You can also isolate a range by completely reducing the volume of the others. For example, if I want to isolate frequencies below 160 Hz, I can set the low-pass filter's frequency to 160 and reduce the volume of the other two ranges.

Update 1 (9-26-2013):
-Added Roll-off controllers

Module: ... r.sunsynth

If you want the volume to remain the same, leave it at 256. I will update the link and reply to this topic when I make changes.

Re: Equalizer

Posted: Mon Jul 22, 2013 8:47 pm
by Darkhog
In other words, you replaced functionality of Equalizer module.

I'm still wailting for equalizer which separates into many frequencies, just like Audacity Equalizer filter or equalizers in popular media players.

Re: Equalizer

Posted: Tue Jul 23, 2013 4:32 am
by The Handle
Darkhog wrote:In other words, you replaced functionality of Equalizer module.
Yeah pretty much. I wanted one where I could see and control the frequencies I was adjusting.
Darkhog wrote:I'm still wailting for equalizer which separates into many frequencies, just like Audacity Equalizer filter or equalizers in popular media players.
I could make one with more ranges, all I have to do is add more chains to it. It's really not that hard to do, I'll put up a picture later showing how it's set up.

Re: Equalizer

Posted: Tue Jul 23, 2013 3:13 pm
by gilzad
I've also created one (10 band), but haven't released it yet because:

The native filters will create a biased signal, even if they're fed with equal loudness and if the band separation is chosen carefully.
This is still not a problem, because you can balance the weighting with inaccessible amplifiers (in a metamodule) to end up with a sound color similar to the source signal (talking about the 0-state of the EQ).

But there's a bigger problem, which makes the EQ not so reliable:
If you have 10 inaccurate crossbands (that's what you get with the filters), they will interfere with each other constructively and destructively. So if you turn up the 100 Hz knob, you might loose some bass at first, because there will be the destructive interference (e.g. with its lower neighbour ~80 Hz). You'd have to turn it up higher until you get the desired boost. At the same time you might get a constructive interference with its higher neighbour ~ 120 Hz, which will force you to tweak the 120 Hz knob down. This action, in turn, creates new constructive and destructive interferences.

So you can have a 10 band EQ for inaccurate EQing but this will be far from acceptable.

Another issue is the amount of so many filters. Except of the lowest and highest band there are 8 bandpass filters, each of them consisting of 2 filters themselves. So there are 8*2 + 2 = 18 filters and they will create a notable CPU usage.

I haven't found a real solution to the mentioned problems yet. One could be - if Alex happens to make one controller control two parameters - to have a parametric EQ some time. This would offer an accurate control over the desired bands and consume less filters.

edit: The Handle's EQ is exactly a parametric 3-Band EQ. Actually, that's the best thing you can have right now. Good job, The Handle!

10-Band EQ

Posted: Tue Sep 24, 2013 5:18 am
by gilzad
Hi all,

here's the 10-Band Equalizer I created: Right-click to download.
I suggest to use the parametric 3-Band-EQ from The Handle, because it takes less resources and affects the original signal less than mine does.
But I've seen that a 10-band EQ has been requested here and there and I even found myself trying to quickly balance several frequency bands at once, so here it is. I'm sorry I don't come up with another article. I prepared a video and everything but wasn't happy with it and heck, it's just an EQ.

However, there's a couple of things you should know about this selfmade EQ:

It will color the sound a lot, even in its zero-state. That's most probably because of the filter-crossover. There's a lot of cross-talking between the border-frequencies of the filters, because each of them is active all the time. I evened out the colored sound as much as I could. I used my monitors, my monitor headphones, fed the EQ with many diferent signals and white noise to have its output sound similar to its input. This comes at the cost of a higher volume, which will sound as loud as the source signal. But since the inaudible crosstalking is there, the EQ will always create a higher volume on its output to sound as loud and to deliver the same color as its source.

You'll see that the 10-band-EQ comes with an integrated 3-Band-EQ. This is possible just by summing up the output of the low-band filters, the mid-band filters and the high-band filters to three separate amplifiers (LoSum, MidSum, HiSum). I found it to be helpful to have some additional rough boosting/attenuating without using futher filters.

I'm sorry that I don't show up here that often anymore. I'm quite busy with this and that but still wanted to share the stuff that is finished on my disk.

See you some time.


Re: Equalizer

Posted: Tue Sep 24, 2013 8:47 pm
by organic io
Good job fellows! I was gonna make something like this a while back but I lost interest, I'm still wishing for a way to zoom into metamodules instead of having to load them separately to edit them.

Re: Equalizer

Posted: Thu Sep 26, 2013 10:41 pm
by The Handle
Added Roll-off controllers (Link updated)

Re: Equalizer

Posted: Sun Mar 16, 2014 8:08 pm
by SolarLune
Hey, this is cool. Nice work! Do you think you could name the source song, with your name as the creator, and save it again as a SunSynth file? That way I know where it comes from later.

Re: Equalizer

Posted: Thu Mar 20, 2014 4:57 am
by The Handle
SolarLune wrote:Hey, this is cool. Nice work! Do you think you could name the source song, with your name as the creator, and save it again as a SunSynth file? That way I know where it comes from later.
I'm a tad bit confused...Are you talking to me or gilzad? If me, do you want the metamodule or the song itself? If you want the metamodule (in sunsynth form) it's in the link I provided in the first post (you can just rename it). If you want the song itself I'll have to organize things a bit before I upload it. I'm uncomfortable with putting my name on it as it's intended to be a community tool, not an attention grabber for myself.

Re: Parametric Equalizer

Posted: Mon Aug 17, 2015 10:01 pm
by SawZer
I was reading this thread and realized that I had solved the EQ bias problem. I'll post a metamodule one I get back home.

The module I made uses phase cancellation to perfectly split a signal into 3 user definable bands. I stopped at 3 bands because the process requires a lot of brainpower to construct, although I'm certain more bands are possible.

Re: Parametric Equalizer

Posted: Thu Aug 20, 2015 5:03 pm
by cube48
^ Heh, that was exactly my thought while I was reading through this old thread. Use of Amplifiers and it's phase invert feature to get rid of the crossbands. I believe you it's mind-bending to patch this correctly. Will try that as well as an exercise.

Re: Parametric Equalizer

Posted: Fri Aug 21, 2015 4:17 am
by SawZer
Link to the module I mentioned.