Preferred filters in CSound?

[Bryan_T]

I’m adding a few filters to my project. I wanted a low pass filter and a high pass filter. I think I opted for lowpass2 and bqrez. But it made me wonder if there are preferred implementations. Thoughts?

[nymano]

In the manual there is a dedicated Filter section, I think it can help you decide which filter would suit your needs: https://flossmanual.csound.com/sound-modification/filters

I suggest trying the examples to see which one sounds good for your project

[rorywalsh]

Check this out too:

Csound filters demonstration

Anton Kholomiov posted some nice instruments to the Csound list today that show the subtle differences between Csound’s filters. I’ve ported his ‘dub-step’ filters examples it as a Cabbage instrument which you can try out here. It’s really quite interesting to hear the differences between the filters. I plan to port his other instruments when I get a chance. CsoundFiltersWobble.csd (4.1 KB) Here are some short sound files demonstrating the various filters. dub-moogvcf.mp3 (706.1 KB) dub-svfil…

Might need some updating, but a great demo instrument.

[Bryan_T]

I tried several last night, basically running a sawtooth wave through them and listening. Obviously, there were differences in sound. And some of them respond quite differently to resonance changes, which scared the heck out of me when they blew up!

But I’m also curious about their computational demands. I’m not sure how to assess that.

[rorywalsh]

I don’t think any of them will demand too much CPU to be honest. You can use the cabbageProfiler opcodes to test them.

[Bryan_T]

That’ll be a useful tool!

[Oeyvind]

Among all nice options, I find the butterworth (butterlp, butterhp, …) to be a good bread and butter filter for general use.

[Bryan_T]

I’m doing some stuff where I’m putting a filter in the feedback path of a delay line. Those buttereorth filters are really great for that since they are so well behaved. Filters with resonance can cause the feedback loop to blow up.

[zephyrbrooks]

Hello,
According to me using lowpass2 and bqrez are good choices for implementing low pass and high pass filters. The preferred implementation can depend on the specific requirements of your project, such as the desired frequency response, computational efficiency, and ease of tuning.