Understanding and Preventing Comb Filters | Live Sound Basics 

Very much appreciated.

Thanks a ton, Colin!

Hey, David! So glad you were able to stumble upon my video. Yes, comb filtering due to the floor bounce was exactly what you were hearing.

So how did you remedy this?

Glad it was helpful!

Thank you!

Isn't that a wonderful graphic from Merlijn Van Veen? I never made that connection to the phase wheel and cardioid patterns until I saw that graphic.

Thank you!

Thank you!

You're very welcome! No I did not build these. I got them from GIK Acoustics. But in my next studio space I plan on building them out.

Cool ! Can’t wait to see 🤟🤟🤟

Great question Ethan! The original phase offset could either be due to a static full-bandwidth time offset, or a gradual timing offset over frequency. In your case, you're talking about a single sine wave - so either of the above changes would have the same result. A 1kHz sine wave has a period of 1ms, so delaying it by 1ms would mean 360° of phase shift. Another 1kHz would still be turning at the same rate of 1kHz, but if it was not delayed it would retain its original timing, and therefore phase, relationship to the other delayed 1kHz sine wave.

@MichaelCurtisAudio Thanks! After days of thinking about it it all finally clicked. So cool to be able to calculate how any specific delay time will create interference across the frequency range! And gives some really interesting compositional ideas too about using flangers with very precise intent to emphasize or deemphasize certain frequencies or even chords within a key or section of a piece!

I wouldn't say that one setup is inherently better than the other, but there's a different set of tradeoffs depending on the system you choose. Having audio sources coupled (close to together) helps eliminate the comb filtering effects, like you said. So, you can either choose to have your mains and subs coupled, or all of your subs coupled. In smaller format ground stacked systems I typically prefer a center sub setup with my mains on sticks, then using crossover appropriately to divide up the low end.

If you're frequently mixing in venues with bands that have a lot of stage volume it's common to matrix out your band group vs your vocal group. You may need more vocals in your front fills that the band since you're getting amps/drums from the stage.

Any skill you want to possess can be cultivated, do not deem yourself done for. You can learn about anything you want as long as you put some time into it

+1 to that!

But more is more, right : )? All jokes aside, I used to make that same mistake.

You're exactly right. This technique is often used more in studio contexts, but it's used in live settings as well. The problem using it live is that the perceived separation it offer only applies to the listener directly in the center of the speakers. If you take one step to the left or right your own physical location now provides the time offset to the left or right speaker, as well as a level change that then results in an imaging change. In my opinion that technique does not translate well to a live context at all, and I only do it in a studio context after applying other heavy processing to the duplicate channel to decorrelate it from the original signal. Dan Worrall and Fab Filter did a great series on this - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-spaqBr-cCFw.html

@@MichaelCurtisAudio It would be great to work for you for a year and just learn, South Africa is a bit far unfortunately. Atleast i can learn from these videos. Thanks Michael.

If you ever get a trip over to the states and get to do some gigs let me know!

Your console needs a digital output. Then your route all your drums to a subgroup, then route that subgroup to a digital out that's picked up in your DAW.

It's on my website homepage at the bottom.