Question about phase and minimum phase EQ

M

Milton_Friedman

New member
If a speaker is tuned to have scooped mids, will it have the same amount of phase distortion that taking a flat speaker and scooping the mids with a minimum phase equalizer would cause?

In other words, if speaker A has scooped mids out of the box, and speaker B is flat, would EQing speaker B to have scooped mids introduce phase distortions that speaker A wouldn't have?

I guess my question boils down to "do normal (non linear phase) equalizers have any quality harming effects that just normal speaker tuning doesn't have?"

I'm referring to when you cut frequencies with an equalizer, I realize boosting frequencies can cause distortion.

Thanks for your help in advance!
 
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You're really having a tough go of it getting that particular nailed down :D

"I guess the question boils down to do normal (non linear phase) equalizers have any quality harming effects that just normal speaker tuning doesn't have?"

I've seen speaker review/measurements that include phase plots through the cross over points and frequency span. Maybe it would be helpful to look at some of them, it'd give some insights and examples as to how some of the different cross overs spin things around' in that regard.
 
I am just actually curious as to why you are asking this question and how it applies to what it is you are planning on doing?
 
I believe the answer to your question is "no". If my understanding is correct (and I can't guarantee that at the moment) speakers are effectively minimum phase devices, so they should act something like analog filters.
 
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bouldersoundguy said:
I believe the answer to your question is "no". If my understanding is correct (and I can't guarantee that at the moment) speakers are effectively minimum phase devices, so they should act something like analog filters.
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I'll go with that ^^^.


I too also want to know this:

jimmys69 said:
I am just actually curious as to why you are asking this question and how it applies to what it is you are planning on doing?
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Because I wanted to do room correction with my EQ, but wanted to make sure that wouldn't screw the phase up.
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Is that what this has been all about?

jonny deep said:
I think it's possible, but you can't move your head.
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Go here..
hunecke.de | Room Eigenmodes Calculator
Plug your room sizes in, click on the various results in the different frequencies it gives.. and see why and what you're up against. .. a) huge eq corrections just to get close to compensating for 10, 20, 30dB room problems, and b) it only relates to that one spot in the room.
 
Milton_Friedman said:
My head is normally in about the same place. But it's also because the speaker doesn't seem totally flat so I wanted to fix that but not mess up the phase.
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It will certainly change the phase response of the system to add eq, but who's to say it doesn't actually improve it? More problematic is judging your speakers' response in a flawed acoustic environment.
 
But the question is do normal (non linear phase) equalizers have any quality harming effects that just normal speaker tuning doesn't have? I think the answer is no

So if I took a non-flat speaker and EQd it to be flat, wouldn't that improve the phase?
 
mixsit said:
Is that what this has been all about?



Go here..
hunecke.de | Room Eigenmodes Calculator
Plug your room sizes in, click on the various results in the different frequencies it gives.. and see why and what you're up against. .. a) huge eq corrections just to get close to compensating for 10, 20, 30dB room problems, and b) it only relates to that one spot in the room.
Click to expand...

I just found the sweet spot in my guitar isolation room with your post. :)
 
Milton_Friedman said:
But the question is do normal (non linear phase) equalizers have any quality harming effects that just normal speaker tuning doesn't have? I think the answer is no

So if I took a non-flat speaker and EQd it to be flat, wouldn't that improve the phase?
Click to expand...

I don't know but I'm betting the answer is something like "Yes, but..." where "but" is followed by a long and technical explanation of the complex variables.
 
mixsit said:
How's that Jimmy? A spot that misses the 'bumps' or..?
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Yes actually, kinda.

I just recently had a guitar player record in the room. Two rigs and two cabinets.

I for some reason tend to face the cabinets at an angle in the room (old bad habit maybe). I couldn't figure out why the 412 cab had less low end quality tone than the 212 combo in there. Both raised off the floor but at different spacing between the length of the room.

Looking at the room mode calculator made me realize the placement could be the issue. Yep!

Even though the room is well treated acoustically, there are still spots where there will be buildup of frequencies. It is still only a 2.28m x 3.5m x 2.5m space, so there are obviously places that have different issues/benefits in a tracking room. A good thing to be aware of in a tracking room because sometimes you want a bit more/less of something...


Anyway, the calculator kinda placed a visual as to where to place the cabinets. And it worked for me as I set up the same rigs tonight with different placement. Much better! :)

Thanks again for that calc post mixit!
 
Here's a strange question but one I need to know the answer to for reasons that would take a while to explain so I don't want to.

Lets suppose that the flat speaker being EQd was voiced in a method that was not minimum phase, would adding a minimum phase EQ to it introduce any quality harming problems that a minimum phase voiced speaker wouldn't have?

In other words you have a non minimum phase voiced speaker being modified by a minimum phase equalizer, compared to a minimum phase voiced speaker.
 
My first answer to ^this^ would be:

Don't use eq on monitors ever. Treat the room. Forget the question...
 
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