General Music Chat

A solution not mentioned in the article is to run all the tracks through an EQ plug-in (use the same one for each track, but individually, not on a bus) - you can set them with a shelf (low pass or high pass), or just with flat response - but this will result in all tracks being in phase.

Really? Please explain exactly HOW an EQ changes the phase of a track.

If the EQ is a good one, it leaves the signal in the same phase that it was recorded. The last thing an engineer would want is a program that intentionally screws up his tracks by flipping the phase of them when he simply desires to increase or decrease a particular tracks frequency response. After all, that is the purpose of EQ.

But even at that, lets say a track is recorded out of phase and another is in phase. Does the EQ flip both of them? Or does it say to itself.. gee that last track was out of phase with the former track?

If you have a track that is in the opposite phase and an EQ puts it in phase, just pure logic dictates that tracks that are in phase would now be put out of phase when put through the same EQ. Thus you have the same problem as before only all the tracks have changed phase.

You can add to the strength of some frequencies or decrease the strength of some frequencies but that has little to do with phase relationships. However, there may be options in some recording programs that might allow you to flip the track so that the phase is reversed.

A solution not mentioned in the article is to run all the tracks through an EQ plug-in (use the same one for each track, but individually, not on a bus) - you can set them with a shelf (low pass or high pass), or just with flat response - but this will result in all tracks being in phase.

Really? Please explain exactly HOW an EQ changes the phase of a track.

If the EQ is a good one, it leaves the signal in the same phase that it was recorded. The last thing an engineer would want is a program that intentionally screws up his tracks by flipping the phase of them when he simply desires to increase or decrease a particular tracks frequency response. After all, that is the purpose of EQ.

But even at that, lets say a track is recorded out of phase and another is in phase. Does the EQ flip both of them? Or does it say to itself.. gee that last track was out of phase with the former track?

If you have a track that is in the opposite phase and an EQ puts it in phase, just pure logic dictates that tracks that are in phase would now be put out of phase when put through the same EQ. Thus you have the same problem as before only all the tracks have changed phase.

You can add to the strength of some frequencies or decrease the strength of some frequencies but that has little to do with phase relationships. However, there may be options in some recording programs that might allow you to flip the track so that the phase is reversed.

"Equalizers are composed of filters, and filters are components that alter the frequency content of a signal. It's a basic function of analog filter design that frequencies within the range passing through a filter are delayed by differing amounts. Time delay in a signal means phase shift, and changes in phase can be audible." - By Brian Smithers
http://www.emusician.com/news/0766/squa ... ase/137064

A solution not mentioned in the article is to run all the tracks through an EQ plug-in (use the same one for each track, but individually, not on a bus) - you can set them with a shelf (low pass or high pass), or just with flat response - but this will result in all tracks being in phase.

... that's very doubtful.

Here is another thing to consider considering the nature of phasing. In the example given with the drum heads, one head is going away from microphone at the top of the drum head. The bottom drum head is miking the head coming towards it. Actually both heads drum ARE going in the same direction.

That being a given, suppose you change the phase of the bottom head mike so that it appears to also be going away from the mike.. You will still have phasing problems due to the time lag caused by the delay of the bottom head being pushed by the air inside of the drum. It takes time to respond to the hit. The time delay causes phasing issues even if both mike diaphragms are moving in the same direction. Now if the mikes are picking up other drums, then there are other phase issues caused by inverting the ambient sound in one mike. Is there something wrong with this logic?

If a guitar plays the same note on one track, and plays the same note on a second track, only not exactly at the same time, there will be phase issues if the two are combined. This is the theory behind the Doppler effect. The Doppler effect can be explained by a moving train. As a train comes towards you the whistle is high pitched as the frequencty of the whistle, as it moves towards you, is combined to the sound of the original signal . As the whistle is heard directly in across from you, you hear the true pitch of the whistle. As the train moves away from you, the frequency of the whistle lowers from your position as the sound of the train leaving causes the pitch to lower through subtraction of the two frequencies. Yeah, I know, my explanation is pretty lame, but Google the Doppler Effect.

The Doppler effect led to the development of phase shifters, flangers and choruses.. The nature of a phase shifter is to take a stationary signal and modulate the same signal, only out of phase, against it by means of a low frequency triangle or sine generator causing the second signal to increase in amplitude or decrease in amplitude as it beats against the stationary signal.. That is a loose explanation of what a phase shifter does and how it does it.

Phasing is a natural phenomena and is present when playing live. The only time it presents a serious problem is when the identical sound is being captured from more than one mike and the signal source is out of phase with the mikes.

Here is another thing to consider considering the nature of phasing. In the example given with the drum heads, one head is going away from microphone at the top of the drum head. The bottom drum head is miking the head coming towards it. Actually both heads drum ARE going in the same direction.

That being a given, suppose you change the phase of the bottom head mike so that it appears to also be going away from the mike.. You will still have phasing problems due to the time lag caused by the delay of the bottom head being pushed by the air inside of the drum. It takes time to respond to the hit. The time delay causes phasing issues even if both mike diaphragms are moving in the same direction. Now if the mikes are picking up other drums, then there are other phase issues caused by inverting the ambient sound in one mike. Is there something wrong with this logic?

If a guitar plays the same note on one track, and plays the same note on a second track, only not exactly at the same time, there will be phase issues if the two are combined. This is the theory behind the Doppler effect. The Doppler effect can be explained by a moving train. As a train comes towards you the whistle is high pitched as the frequencty of the whistle, as it moves towards you, is combined to the sound of the original signal . As the whistle is heard directly in across from you, you hear the true pitch of the whistle. As the train moves away from you, the frequency of the whistle lowers from your position as the sound of the train leaving causes the pitch to lower through subtraction of the two frequencies. Yeah, I know, my explanation is pretty lame, but Google the Doppler Effect.

The Doppler effect led to the development of phase shifters, flangers and choruses.. The nature of a phase shifter is to take a stationary signal and modulate the same signal, only out of phase, against it by means of a low frequency triangle or sine generator causing the second signal to increase in amplitude or decrease in amplitude as it beats against the stationary signal.. That is a loose explanation of what a phase shifter does and how it does it.

Phasing is a natural phenomena and is present when playing live. The only time it presents a serious problem is when the identical sound is being captured from more than one mike and the signal source is out of phase with the mikes.

A popular implementation of a phase shifter is using an all-pass filter, sweeping the center frequency of the filter by voltage control with a sine or triangle wave shifts the phase relative to the input signal. Additional filter poles and or increasing the filter resonance (feedback of output to input) will create a more pronounced effect.

"Equalizers are composed of filters, and filters are components that alter the frequency content of a signal. It's a basic function of analog filter design that frequencies within the range passing through a filter are delayed by differing amounts. Time delay in a signal means phase shift, and changes in phase can be audible." - By Brian Smithers

Yes.

But the key is "frequency content" dealing more with harmonic enhancement, not so much frequency change. After all, aren't we speaking of microseconds between the input and the ouput of an EQ?

If an EQ did seriously change the frequency, then all the instruments would become out of tune, and that is not the case. Have you ever listened to one of your tracks after you have EQ'd it? Did it sound radically out of tune or even mildly out of tune to you?

Although time delay will cause phasing to a note, it does not significantly detune the note, at least in my limited experience. . However radical variable delay in frequency will cause detuning, such as in a flanger, but nothing of such radical consequence happens when EQ ing a signal in anything I have ever EQ'd.

For instance, the tone control on your guitar does not throw your out of tune, it simply muted higher frequencies, even though the cap and pot in the circuit are a filter network or in other words, a basic RC EQ.

"Equalizers are composed of filters, and filters are components that alter the frequency content of a signal. It's a basic function of analog filter design that frequencies within the range passing through a filter are delayed by differing amounts. Time delay in a signal means phase shift, and changes in phase can be audible." - By Brian Smithers

Yes.

But the key is "frequency content" dealing more with harmonic enhancement, not so much frequency change. After all, aren't we speaking of microseconds between the input and the ouput of an EQ?

If an EQ did seriously change the frequency, then all the instruments would become out of tune, and that is not the case. Have you ever listened to one of your tracks after you have EQ'd it? Did it sound radically out of tune or even mildly out of tune to you?

Although time delay will cause phasing to a note, it does not significantly detune the note, at least in my limited experience. . However radical variable delay in frequency will cause detuning, such as in a flanger, but nothing of such radical consequence happens when EQ ing a signal in anything I have ever EQ'd.

For instance, the tone control on your guitar does not throw your out of tune, it simply muted higher frequencies, even though the cap and pot in the circuit are a filter network or in other words, a basic RC EQ.

Altering of the frequency content is not altering the pitch of the instruments, or anything! ... but alters the harmonics that comprise the signal.

From Wiki "A harmonic of a wave is a component frequency of the signal that is an integer multiple of the fundamental frequency, i.e. if the fundamental frequency is f, the harmonics have frequencies 2f, 3f, 4f, . . . etc. The harmonics have the property that they are all periodic at the fundamental frequency, therefore the sum of harmonics is also periodic at that frequency. Harmonic frequencies are equally spaced by the width of the fundamental frequency and can be found by repeatedly adding that frequency. For example, if the fundamental frequency is 25 Hz, the frequencies of the harmonics are: 50 Hz, 75 Hz, 100 Hz etc."

But the key is "frequency content" dealing more with harmonic enhancement, not so much frequency change. After all, aren't we speaking of microseconds between the input and the ouput of an EQ?

I believe that is what I said.

A popular implementation of a phase shifter is using an all-pass filter, sweeping the center frequency of the filter by voltage control with a sine or triangle wave shifts the phase relative to the input signal. Additional filter poles and or increasing the filter resonance (feedback of output to input) will create a more pronounced effect.

I think we are saying the same thing. That feedback is the purpose of the regeneration control. The true phasing itself is accomplished through beating a variable amplitude signal against a signal of opposite phase in most designs. As the out of phase signal increases and decreases in amplitude it changes the harmonics and frequency at the output. That is the Doppler effect. The variable filter is a natural phenomena that is derived when the two signals interact.

Without the regeneration, you have a true Vibrato and an actual Doppler frequency change. I used to leave out the regeneration and go for the vibrato when I wanted to get that Magnatone sound.

The EQ pass-through thing I read was obviously wrong, not sure where I read it, but it was one of a series of articles, that basically said to run all the tracks through an EQ plugin first.

The EQ pass-through thing I read was obviously wrong, not sure where I read it, but it was one of a series of articles, that basically said to run all the tracks through an EQ plugin first.

WTH is that supposed to do? Besides make the mix sound crappy?

Mike N - you could set all parameters of the EQ at Zero, or use a high-pass (set at an appropriate low frequency) across everything except for the bass guitar and kick.

Mike N - you could set all parameters of the EQ at Zero, or use a high-pass (set at an appropriate low frequency) across everything except for the bass guitar and kick.

I have a retarded question for you.
Do you need to run everything through a compressor before tracking, or is that something you can do while mixing?

I ask because we have no outboard compressors.
I was hoping that the software would have one.

Mike N - you could set all parameters of the EQ at Zero, or use a high-pass (set at an appropriate low frequency) across everything except for the bass guitar and kick.

I have a retarded question for you.
Do you need to run everything through a compressor before tracking, or is that something you can do while mixing?

I ask because we have no outboard compressors.
I was hoping that the software would have one.

I think it is more advantageous to compress when tracking if you are recording to analog tape or to 16 bit digital .. where there is a greater limitation of headroom. With a 24 or 32 bit depth digital you can easily record without compression, which give you more options later when mixing.

Often it can be useful to duplicate your uncompressed track and add compression to the copy, then you can mix the compressed track with the dry track to get the desired amount of thickening without blunting the transients in the original signal.

Mike N - you could set all parameters of the EQ at Zero, or use a high-pass (set at an appropriate low frequency) across everything except for the bass guitar and kick.

I have a retarded question for you.
Do you need to run everything through a compressor before tracking, or is that something you can do while mixing?

I ask because we have no outboard compressors.
I was hoping that the software would have one.

There are circumstances where you'd want to record with a compressor, such as vocals of certain pitch, or enunciation. The pop Filters help, but some folks have screechy , banshee-like voices than need reigning in while going in. Sometimes post compression works best. Certain Lead solos, for example should prolly be recorded as raw and dirty as possible, and the refined in the mix . But there really is no right or wrong ..its waht sounds good and works at the time.

But the key is "frequency content" dealing more with harmonic enhancement, not so much frequency change. After all, aren't we speaking of microseconds between the input and the ouput of an EQ?

I believe that is what I said.

A popular implementation of a phase shifter is using an all-pass filter, sweeping the center frequency of the filter by voltage control with a sine or triangle wave shifts the phase relative to the input signal. Additional filter poles and or increasing the filter resonance (feedback of output to input) will create a more pronounced effect.

I think we are saying the same thing. That feedback is the purpose of the regeneration control. The true phasing itself is accomplished through beating a variable amplitude signal against a signal of opposite phase in most designs. As the out of phase signal increases and decreases in amplitude it changes the harmonics and frequency at the output. That is the Doppler effect. The variable filter is a natural phenomena that is derived when the two signals interact.

Without the regeneration, you have a true Vibrato and an actual Doppler frequency change. I used to leave out the regeneration and go for the vibrato when I wanted to get that Magnatone sound.

I think we are saying the same thing ... for the most part

Maybe we differ on the definition of regeneration? ... I'd consider it to be mixing of the output of the filter back into the input of the filter along with the original signal .. feedack. Mixing the dry signal with the output I would not call regeneration or feedback.

http://www.geofex.com/article_folders/p ... phase.html
" ... Magnatone used either one or two stages of this, depending on the amp, and never did the addition of the dry signal that would have made it into a true phase shifter. They settled for the electronic vibrato that it produced. This was the first true vibrato in an amp. Still, as complicated as it was for Magnatone to do it, it's still a variant of the simple R/C phase stage."

Mike N - you could set all parameters of the EQ at Zero, or use a high-pass (set at an appropriate low frequency) across everything except for the bass guitar and kick.

I have a retarded question for you.
Do you need to run everything through a compressor before tracking, or is that something you can do while mixing?

I ask because we have no outboard compressors.
I was hoping that the software would have one.

Many people will compress bass when tracking. You don't need outboard compressors when recording, you can use plug-ins which gives you the option to change settings after tracking.