Question about phase and Minimum Phase EQs

M

Milton_Friedman

New member
Many speakers meant for recreational listening have boosted or cut responses. For instance, many hifi speakers have scooped mids. My question is if there is a speaker that's 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?
 
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It's unlikely that you'd be able to recreate the exact frequency response of one set of speakers on an entirely different set of speakers with a completely different function and design, although with a lot of work you might get close... Let alone the question of why one would attempt to do that?

Is there a question behind your question? If so, what would that be?

GJ
 
I think you misunderstood the question because I'm not asking about frequency response, I'm asking about phase. I edited the question to make it clearer. :)
 
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My personal opinion is that you should do that regardless (buy another set of speakers). Flat monitors are great for mixing, but don't have what a lot of us "expect" from a set of speakers. So you can augment your mixing gear _and_ use the second set for home listening as well. I think a studio should have several choices in speakers for monitoring that are more "real world." Then you won't have to run around to all these different locations and from car to car as much to check your mixes out.

Even Phil Spector mixed on AM radio speakers way back in the 60's. I'm not saying flat-response monitors don't have their place, but so-called "hyped" hi-fi speakers have a place too; they keep our mixes honest and grounded in what is closer to listening reality for many people.

GJ
 
Ok but that still doesn't answer my question. :/

I know flat monitors don't have what we expect for listening purposes, but you could fix that with an EQ
 
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Like I said, you might get close with a lot of work. Since you're considering buying a second set anyway, and I think that's a better idea, I was trying to nudge you in that direction...

GJ

PS-- You can "smiley face" any set of speakers with any eq (not even a special what-have-you-not), so that's certainly an option. Just not so good an option, IMHO ;)
 
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Exactly, I'm asking if said smiley face eq would cause any phase distortion that a speaker that's tuned to have a smiley face frequency response wouldn't have.
 
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short answer - yes you will induce phase distortion simply because the eq will regardless of how linear the phase response is

- without a series of custom complex all-phase filters added to readjust the phase response of the signal to what it was before eqing, there will be phase distortions

- this is normal whether you do it with sw or hw and is a hallmark of what your listeners will be hearing on their speakers anyway if they apply their own eq
 
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Milt, you seem set on doing it. I guess you should then... ("A man's gotta do what a man's gotta do.")

GJ
 
bandcoach said:
short answer - yes you will induce phase distortions imply because the eq will regardless of how linear the phase response is

- without a series of custom complex all-phase filters added to readjust the phase response of the signal to what it was before eqing, there will be phase distortions

- this is normal whether you do it with sw or hw and is a hallmark of what your listeners will be hearing on their speakers anyway if they apply their own eq
Click to expand...


Right, but my question is "Many speakers meant for recreational listening have boosted or cut responses. For instance, many hifi speakers have scooped mids. My question is if there is a speaker that's tuned to have scooped mids, will it have the same amount of phase distortion that taking a flat speaker and scooping the mids with an equalizer would cause?"
 
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and my answer stands... yes you will induce phase distortion simply by virtue of using eq (regardless of how linear their impact on phase it will still have an impact) to change the signal before sending it to your monitors, as for whether it will be more or less than using hifi speakers only your ears or a lot of expensive test equipment can tell you that for sure
 
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bandcoach said:
and my answer stands... yes you will induce phase distortion simply by virtue of using eq (regardless of how linear their impact on phase it will still have an impact) to change the signal before sending it to your monitors, as for whether tit will be more or less than using hifi speakers only your ears or a lot of expensive test equipment can tell you that for sure
Click to expand...

But I know an EQ will cause phase distortion, that's not my question.
 
I just re-read you question again sometimes white space helps to present your ideas

in a nutshell you are asking us to compare apples and oranges:

The question about apples
does a hifi speaker designed to be poor in reproducing low mids introduce phase distortion to the signal reproduced through it as a result of the design?

answer maybe - it depends on the crossover inside the box; chances are that there will be phase distortion caused by the crossover design to do with the nature of low pass and high pass filters used in the crossover itself: if it uses a woofer, squawker and a tweeter and is using a fully spec'd inductance-capacitance crossover network there will be 4 sources of phase distortion:

low-pass to woofer,
high pass to squawker,
low pass to squawker,
high pass to tweeter

If it is using woofer-tweeter then there are two sources of phase distortion:
low-pass to woofer,
high pass to tweeter

If it is using a bi-cone approach then there will be distortion issues due to the stiffness of the two cones interacting and cancelling each other out at the crossover frequency they are designed to kick in at

and

The question about oranges
if I were to use linear phase EQ with my relatively flat monitors to reproduce that scooped frequency response would the level of phase distortion be similar

answer yes/no/maybe :we cannot be more definitive than that as there are way too many variables to give a considered answer let alone an accurate one
 
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bandcoach said:
The question about oranges
if I were to use linear phase EQ with my relatively flat monitors to reproduce that scooped frequency response would the level of phase distortion be similar

answer yes/no/maybe :we cannot be more definitive than that as there are way too many variables to give a considered answer let alone an accurate one
Click to expand...
Thank you for your response.

No not a linear phase EQ, I'm asking about a minimum phase EQ
 
Ok, I got that bit wrong, however,

The question about oranges
if I were to use minimum phase EQ (i.e. typical hifi eq such as designed by baxandall, chebyshev or butterworth) with my relatively flat monitors to reproduce that scooped frequency response would the level of phase distortion be similar

answer yes/no/maybe: we cannot be more definitive than that as there are way too many variables to give a considered answer let alone an accurate one

i.e. regardless of the filter/eq type the answer remains the same because we do not know the variables that you are hearing
 
I still don't know if you understand the question.

I think what my question boils down to "do normal (non linear phase) equalizers have any quality harming effects that just normal speaker tuning doesn't have?"
 
Milton_Friedman said:
I still don't know if you understand the question.

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

and the answer is yes/no/maybe - without specific brands and settings the point is moot - normal hifi eq (aka minimum phase eq) always introduces some phase shift to one part or another of the frequency spectrum - even when flat there are still phase anomalies produced by the non-linearity of the circuit and the fact that unless every component is carefully hand selected and matched there will be shifts due to differences in values used.

most transducers are built to be as flat as possible (leaving aside structural resonances). When used in hifi settings, there may be phase delays built in to the passive crossovers to ensure that the drivers are reproducing in linear phase (not to be confused with equalisers of the same name). In addition, there may be other phase distortions caused by the inductors and capacitors in such crossover networks
 
simply put any hifi speaker cabinet with 2 or more drivers will have some form of crossover implemented. As the elements in such a crossover are most likely inductors and capacitors there are phase delays introduced that are related to the crossover frequency, the bandpass range and the actual elements themselves

in addition you can add phase delay unit blocks to time align the drivers - an important step if you want to have true linear phase reproduction at the driver-air interface (no point in the high frequency components being delayed by 360[sup]o[/sup] or more due (which can be on the order of several ms and given that the ear is discriminatory down to the microsecond for high frequency direction) to crossover related phase delays)


. . . . . . . . . . . { high freq -> tweeter
signal -> crossover ->{
. . . . . . . . . . . { low freq -> phase delay -> woofer
 
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