REW Beta Release Dashed line into new Aligment tool

[FidelioX]

Hi guys, yesterday (for the first time) I used the Alignment tool in the latest beta release of REW.
Do you know what indicates the dashed black line that you can see here at the top of others??

thank you

 

[John Mulcahy]

The help knows

The Alignment tool allows gain, polarity and delay adjustments to be made to a pair of measurements with a live preview of the summed result updated as the parameters are changed (the preview uses log spaced data at 96 PPO so may differ slightly from the final result). There is also a dotted trace which shows the result of a summation of the measurements ignoring phase.

 

[FidelioX]

The help knows

The Alignment tool allows gain, polarity and delay adjustments to be made to a pair of measurements with a live preview of the summed result updated as the parameters are changed (the preview uses log spaced data at 96 PPO so may differ slightly from the final result). There is also a dotted trace which shows the result of a summation of the measurements ignoring phase.

in which cases does having this reference helps?

thank you

 

[Cristianolo]

in which cases does having this reference helps?

thank you

helps you identify the maximum theoretical SPL that the system can reach
If there is perfect alignment, the solid black line coincides with the dashed line

 

[FidelioX]

helps you identify the maximum theoretical SPL that the system can reach
If there is perfect alignment, the solid black line coincides with the dashed line

Very interesting.
Please be patient ... i'm new about this.
About the posted test ... i've tried any position of delay and polarity of the second sub and never reached the doted line. In some portions yes ...but not totally.
So...in theory ... what is missing to reach the doted line?

Thank you

 

[sm52]

what is missing to reach the doted lin

The placement of speakers, furniture, etc. in the room, what's inside the electronic devices, and much more. Sometimes it is better to leave it as is, achieving the maximum with simple actions.

 

[Cristianolo]

Very interesting.
Please be patient ... i'm new about this.
About the posted test ... i've tried any position of delay and polarity of the second sub and never reached the doted line. In some portions yes ...but not totally.
So...in theory ... what is missing to reach the doted line?

Thank you

This will only be possible (black line touches the dotted line) if, for the entire frequency range, the acoustic phase is equal (coincident) for all transducers.
In a room with multi-subs, each in a different location, with different reflections, different acoustic modes, etc., this does not happen.
One way to try to improve this is to use a DSP that has FIR filters for phase correction.

 

[ManCaveAudio]

Very interesting.
Please be patient ... i'm new about this.
About the posted test ... i've tried any position of delay and polarity of the second sub and never reached the doted line. In some portions yes ...but not totally.
So...in theory ... what is missing to reach the doted line?

Thank you

You can try to mach Impulse or Phase Alignment at various frequencies within crossover region to achieve the best sum.