Noob Question on Low Pass filter

H-evolve

Member
Apr 21, 2014
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Montreal, Canada
Hi all,

I'm working on a home made demo at the moment, and I was wondering this very noob question... Is this normal that I have to stack more than 1 low pass filter to get rid of the fizz on quad tracks - 2 mic per track guitar tracks?

Let me explain:
- We've recorded 4 tracks: 2 on a ENGL Savage + ENGL XXL and 2 on a Dual Rectifier + Mesa OS Cab
Each recording is with a SM57 + e906 mic.

I'm pretty sure the fizz comes from multiple imperfections in my setup, and what I find is that when having so many tracks for my rythm guitars, even if I did put a high pass/low pass on each individual mic track (so 8 total), I still have a decent amount of garbage in the highs (6kHz ishhh and above..)

I'm basically wondering if it's very possible and relatively normal. First time I work with so many tracks...

Thanks for the help.
 
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Exchange one of the lowcuts for a narrow high-freq cut (bell shape). You often get spikes in the 10k area which simply ignore most hicuts, because they are too close and too loud. As soon as they are gone, it´s much easier on the ear
 
Interesting... I wasn't seeing anything weird on my curve, but then this is probably not extremely precise. I'm using ToneBooster also, which is relatively unexpensive. And also, I was finding my tone quite "bright", so I was using a low pass with a relatively progressive shape, and I set it so that it starts a bit lower than usual (7kHz I think...). So I would have thought that the 10 kHz you talk about was already cut by a good 3 to 4 dB minimum. But maybe it's not, I'll investigate that range above 6k with more details tonight. Thanks for the tip.
 
What is the slope of your low pass filter? A single pole (6dB per octave) filter won't cut as much high end as a double pole (12dB per octave) filter, which won't cut as much as a triple pole (18dB per octave) filter, and so on.

See if your plugin allows you to change the slope.
 
What is the slope of your low pass filter? A single pole (6dB per octave) filter won't cut as much high end as a double pole (12dB per octave) filter, which won't cut as much as a triple pole (18dB per octave) filter, and so on.

See if your plugin allows you to change the slope.

With ToneBooster EQ, you have 2 slopes available, however I don't recall having a clear indication on what is the actual value of the slope in that program. I'll double-check tonight. But for sure the one I used was very slow acting, therefore possibly not cutting enough shit at the 10+ kHz.
 
So I would have thought that the 10 kHz you talk about was already cut by a good 3 to 4 dB minimum.

i usually add a narrow cut between 3 and 10 dB up there, if there is actual problematic content up in the treble freqs. On top of the hicut.
These fizzy highs can be really loud, depending on the speaker and mic position
 
some filters (like RenEQ) have a passive kind of behaviour where they're quite subtle. its annoying advice but just listen and do whatever it needs....try not to worry about the values or how it looks.

I think I made it slightly better using local notches on top of the low pass. At some point I had to stop cause I was just removing too much in the top end and guitars were not as interesting, a bit dull... So I think with the quality of the recording that I have, I won't be able to do a lot better. But, it's still an improvement, so that's that.

I'll probably share, for those interested, the track in question in the next few days. If you want, you'll be able to criticize what you don't like
 
I'd suggest to use LP and HP on grouped tracks (on "guitar" or all rhythm guitars with respective mics). Because doing filtering on individual mics that are supposed to be as in a phase as possible will shift low-end and hi-end phase shifting. And that could cause resonance in nasty frequencies.
 
I'd suggest to use LP and HP on grouped tracks (on "guitar" or all rhythm guitars with respective mics). Because doing filtering on individual mics that are supposed to be as in a phase as possible will shift low-end and hi-end phase shifting. And that could cause resonance in nasty frequencies.

Oh ok I really didn't know that. Do you recommend doing all of the EQ'ing on the group track then? Or only the LP and HP filters?
 
Oh ok I really didn't know that. Do you recommend doing all of the EQ'ing on the group track then? Or only the LP and HP filters?
I'd suggest to do it on group, unless you have something realy specific going on individual mic, then I'd use linear phase EQ. Think about it - you need to shape one whole sound that's happened to be made out of smaller pieces.