# Phase Plot



## Iain Apple (Feb 22, 2009)

Hi,

It must be me, but I can't find a setting to show a phase plot. 

If it's not me. Will this be available in a future version?

Thanks.

Iain.


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## JohnM (Apr 11, 2006)

It's not you  and yes, the next release has phase and group delay plots.


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## Iain Apple (Feb 22, 2009)

Hi,

Thanks for your reply. But also thank you very much for the software. It is very impressive. Since it looks like you are going to add more features. I would like to make a few requests, if possible.

Coherence view and variable blanking (4 steps?)
Setup presets (maybe 6)
Addition of measurements, eg stitching of LF port to main etc. like MLSSA.
Defined averaging. ie vector/RMS.

Iain.

ps AES UK section meeting on the 10th March looks interesting.


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## JohnM (Apr 11, 2006)

REW only makes one calculation of the response, when multiple sweeps it pre-averages synchronously in the time domain before FFT so coherence would be 1. Frequency domain averaging is on the list to be looked at though, and I'll take note of the other items. What settings would you like captured in the presets?


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## Iain Apple (Feb 22, 2009)

John,

"REW only makes one calculation of the response, when multiple sweeps it pre-averages synchronously in the time domain before FFT so coherence would be 1."

Ok, but in "RTA" mode, I would have thought it would be helpful. Of course it's better to do an impulse and go from there.

"What settings would you like captured in the presets?"

Soundcard/Interface settings
Levels. 
Time Offset
General Measurement/Generator settings
Mic Cal file

Iain.


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## DrWho (Sep 27, 2006)

I just wanted to echo a big thanks for the software too...I have found it extremely helpful in all sorts of applications. :T

One minor request....when using the loopback feature, would it be possible for the ETC and impulse to show absolute time?


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## JimP (May 18, 2006)

John,

Will the phase plot provide for equalizer induced phase shift?


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## JohnM (Apr 11, 2006)

JimP said:


> Will the phase plot provide for equalizer induced phase shift?


Depends what you mean. If the equaliser is in the measurement path its phase shift will be included in the measurement.


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## JohnM (Apr 11, 2006)

DrWho said:


> One minor request....when using the loopback feature, would it be possible for the ETC and impulse to show absolute time?


It is certainly possible, are you aiming to compare arrival times between different measurements, e.g. to check speaker or drive unit time alignments?

A feature I have already included is an option to eliminate measurement delays through a process of cross correlation of the captured impulse with its minimum phase counterpart, that has the effect of finding the zero time of the system itself and eliminates all the time delays, whether in the soundcard path or the system itself.


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## DrWho (Sep 27, 2006)

JohnM said:


> It is certainly possible, are you aiming to compare arrival times between different measurements, e.g. to check speaker or drive unit time alignments?


Yep :T

It would also aid in multi-speaker systems...like a church or live venue with delay stacks, etc...


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