Linear Phase EQ?

As part of my normal "getting my mixes to sound......err......less crappy", I find myself notching quite a bit of nasty frequencies out of vocals, acoustics, etc.  I usually use a "normal" EQ for this...high Q...sometimes up to 20 notches.  I was reading a little bit for the necessity of a Linear Phase EQ for this kind of surgical work, but am not sure about the sonic -- and CPU intensive -- differences.
 
Anybody know when/when not to use Linear EQs?  I use this notch technique in both stereo and mid-side tweaking as the mix unfolds.  It's amazing what a difference it makes when you A/B it.  Thanks gang!

If your having to notch out to much of a linear phase EQ then you have not done proper EQ for your tracks. My advice is go to Groove 3 and watch the videos on EQ. You should only have to make minor adjustments, in any, on a  LPEQ.

Guitarpima
If your having to notch out to much of a linear phase EQ then you have not done proper EQ for your tracks. My advice is go to Groove 3 and watch the videos on EQ. You should only have to make minor adjustments, in any, on a  LPEQ.

Thanks dude...I'll check out the Groove 3 vid...I was actually talking about individual track notching, not final mix...but still don't know when it's beneficial to use linear vs. regular EQ.

Linear-phase EQ isn't the solution you're looking for. If you're doing a lot of notching on vocals, the problem is resonances in your room. Get some acoustical absorption around you when you track your vocals, even if it means dragging the mic into a closet and surrounding yourself with winter coats. Get away from walls and windows. Even with a cheap microphone you should not have to do extensive EQ on vocals, certainly not "lots" of notches.
 
 

I always understood phasing issues to be more associated with boosting than cutting. I've certainly never considered linear phase EQs on tracks needing some notching.

I think your misunderstanding. I don't quite understand it either but a regular EQ smears the frequencies when you shape them the way you want. The LPEQ does not do this which is why it is so CPU intensive.

I just watched it as well. I wish X3 had that analyzer in the EQ. That would be cool!

Equalizers, by nature, shift phase. However, it's rarely an issue because under normal conditions the effect is simply not audible.
 
The truth is that we cannot hear phase shift. We can only hear the side-effects of phase shift when we add two versions of the same (or very similar) signal that are not in phase with one another.
 
For example, if you record one source with two microphones, it's possible that by using different (and extreme) EQ settings for each microphone you could conceivably hear comb filtering at some frequencies. More likely, just the fact that you used two microphones is going to be a far greater concern. Presumably, the OP is singing into just one microphone.
 
So-called "linear-phase" equalizers shift phase, too. They just shift all frequencies by the same amount so they remain in sync with one another across the spectrum. It's one of the reasons linear-phase EQs are primarily used on the master bus, because the delay doesn't matter when filtering the entire mix. A linear-phase equalizer would still cause comb filtering under the conditions described above, except that it might be even more noticeable because it'd be across the board, not limited to a particular frequency range.
 
Extremely narrow notches (and boosts) can cause another problem - not related to phase shift - called ringing. This is what happens when the Q is so narrow that the filter is on the edge of being an oscillator. It's usually something to be avoided, but it applies to all equalizers, uh, equally. You can't avoid it by choosing a different EQ.

Just to clear something up; Sonar's PDC takes care of the LP EQ if you put in on a track, so you really shouldn't get phase issues by using it on a regular audio track instead of the master bus.

That's why I suggested treating the problem at the source, acoustically. It'll preclude the need for extreme corrections later.