Question about EQ poles and the artifacts/phase they may/may not raise

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-- Question about EQ poles and the artifacts/phase they may/may not raise

Posted by DjStephenWiley on Jul-17-2010 23:20:

Question about EQ poles and the artifacts/phase they may/may not raise

I recall reading a book one time that emphasized the use of 6dB, 12dB (the best it said), and 24dB filters. It said anything higher starts to really create artifacts and phasing problems.

I'm asking this because EQ's like the FabFilter Pro-Q have slopes of up to 48, and I don't have a lot of experience with it or any other EQ's using 48dB slopes.

Could anyone with some knowledge here shine some light on the subject?

Thanks!

Posted by Zombie0729 on Jul-18-2010 01:03:

hmm... i have no idea. why would an eq cause phasing problems?

Posted by Zak McKracken on Jul-18-2010 01:16:

take me home

Posted by MSZ on Jul-18-2010 03:13:

quote:
Originally posted by 19503
take me home

country road

Posted by kitphillips on Jul-18-2010 13:00:

I don't know and only one or two people on here will. Search on Gearslutz IMO.

Oh, but for your own interest, set the slope on a low pass to 48 and sweep it, you'll notice a weird resonance. You get less of that with shallower slopes. Thats one issue. Another is the strangeness of these filters as they approach a brickwall. You just don't get those sharp cutoffs in nature and they sound very artificial to our ears. Those things are two issues but I think that they're seperate to the phase issue, which I don't frankly understand.

Posted by farris on Jul-18-2010 13:42:

quote:
Originally posted by msz
country road

quote:
Originally posted by 19503
take me home

to the place I belong...

Posted by Stephen Wiley on Jul-18-2010 14:00:

quote:
Originally posted by kitphillips
I don't know and only one or two people on here will. Search on Gearslutz IMO.

Oh, but for your own interest, set the slope on a low pass to 48 and sweep it, you'll notice a weird resonance. You get less of that with shallower slopes. Thats one issue. Another is the strangeness of these filters as they approach a brickwall. You just don't get those sharp cutoffs in nature and they sound very artificial to our ears. Those things are two issues but I think that they're seperate to the phase issue, which I don't frankly understand.

same. i read it i believe in "mixing audio" - but yea, i have def noticed the unexpected results on a 48 pole filter. sounds like shit usually imo. 24 keeps the sound musical and offers plenty of cut.

Posted by kitphillips on Jul-18-2010 17:14:

I've just been going back to using the least cut possible tbh. Generally 6 is fine for everything but the low cut on the master which I use an 18/24 for.

Posted by DJMaytag on Jul-18-2010 20:07:

digital EQ's will have some phasing or coloration problems, but they are miniscule in comparison to analog EQ's found on outboard gear and on analog mixing desks. most EQ plugins are designed to minimize phasing problems and some even have switches to turn these optimizations on and off (at the expense of CPU horsepower).

that said, sometimes these artifacts are actually quite desirable, in both analog and digital EQ's.