So many things to correct or dispel here!
In most modern recording facilities the mics are converted to digital on entry into the mixing console. As such the EQ, which in reality is very rarely used, is done in the digital domain and there is no phase shift as in analog.
Yes, many recordings are done instrument by instrument, it doesn’t matter which mics are used because every mic in the studio is wired the same way so a positive going signal is always positive. When multiple mics are used at once they are all in phase, this matters because, especially on drums which are always multi micced, the same sound is captured by multiple mics but at different volume levels. I.e. the Tom mic pics up some of the kick too. If the mics were not wire the same that overlap would be subtractive. The doing things at different times has no bearing on anything as the signals from different instruments are not phase timed with each other ever, that’s what makes it sound the way it does as opposed to being computer generated.
This whole discussion is meant to be about phase of your system at home. And yes it does matter.
One more old thread, the same questions...
I found that the polarity matters after the stage that adds more of even order distortions in dynamics. Usually it is the power amp, so input polarity changes nothing, while change of the output polarity, from the amp to speakers, is audible. And the more distortions the amp adds, the more it is audible, especially in the nearfield. The farther from speakers, the less it matters.
I found that the polarity matters after the stage that adds more of even order distortions in dynamics. Usually it is the power amp, so input polarity changes nothing, while change of the output polarity, from the amp to speakers, is audible. And the more distortions the amp adds, the more it is audible, especially in the nearfield. The farther from speakers, the less it matters.
I haven't delved much into the subject of equalisers, but I did come across this Equalizers and Phase Shift. He gives a brief description of digital equalisation using shift registers to introduce delays, and contrasts the procedure with analogue equalisation using capacitor/inductor networks. The discussion includes the line:
With an analog EQ the delays (phase shift) are created with capacitors and inductors. In a digital EQ the delays are created with a tapped shift register. But the key point is that all EQ shifts phase, unless it uses special trickery.
Now, he doesn't elaborate on what "special trickery" might be employed, but he does give the impression that run-of-the-mill digital equalisation will involve phase shifts just as much as analogue equalisation does.
Many are like that, yes. I don't own a stand alone function generator any longer but instead just use the computer and a sound card. I could make you a nice sawtooth and post it here if you like.
cnpope,
Thanks for mentioning that some Digital Equalizers introduce delays (such as one frequency is delayed more than another).
In my earlier post, I asked the question, what about Group Delay.
I forgot to explain group delay to those who do not know what it is.
Across a band of frequencies, some of those frequencies may be delayed more than others. The measurement unit of group delay is time.
In simple terms, different times changes the relative phase of 2 or more frequencies. (suppose the 2nd harmonic of a 440Hz music note is delayed, that means the phase is different).
Hopefully, most multiple driver speaker systems have all the drivers in phase acoustically.
And a measurement of that is called Group Delay.
Things are not always as simple as they first appear.
Thanks for mentioning that some Digital Equalizers introduce delays (such as one frequency is delayed more than another).
In my earlier post, I asked the question, what about Group Delay.
I forgot to explain group delay to those who do not know what it is.
Across a band of frequencies, some of those frequencies may be delayed more than others. The measurement unit of group delay is time.
In simple terms, different times changes the relative phase of 2 or more frequencies. (suppose the 2nd harmonic of a 440Hz music note is delayed, that means the phase is different).
Hopefully, most multiple driver speaker systems have all the drivers in phase acoustically.
And a measurement of that is called Group Delay.
Things are not always as simple as they first appear.
Set one scope lead on the input, and trigger on that input.
Set the output to display the sine wave on the same screen.
Do they track each other?
Can you move one on top of the other?
They are in phase if they both go up at the same time, down at the same time.
If they cross, one up while the other is down, then it inverts.
One very experienced member of our club investigated this extensively, and came to the conclusion that the pressing and mastering people in large part arent considered with absolute phase.
You can check your amplifier and know for sure.
Set the output to display the sine wave on the same screen.
Do they track each other?
Can you move one on top of the other?
They are in phase if they both go up at the same time, down at the same time.
If they cross, one up while the other is down, then it inverts.
One very experienced member of our club investigated this extensively, and came to the conclusion that the pressing and mastering people in large part arent considered with absolute phase.
You can check your amplifier and know for sure.