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In Reply to: RE: Phase Matching and Delay/Time Alignment Example Plots posted by emailtim on July 25, 2020 at 11:28:00
What does the 0ms SPL curve look like? It's a little hard to see with all the other delays shown.
Are you using RePhase to set the delay times and then using REW to measure all this?
I'm familiar with the REW group delay plots, but not these. Maybe I'm not using the right settings. Does the latest version of REW produce these? I'm using an older version.
"... What does the 0ms SPL curve look like? ..."
The 0ms is the green trace heading South West on the PHASE and the green trace second from the bottom of the 250Hz dip on the SPL plot (both just above the bottom/lowest 4ms purple trace).
I should have varied the line styles for added clarity.
"... Are you using RePhase to set the delay times and then using REW to measure all this? ..."
I made all of the linear filters in RePhase.
Exported REW's PEQs as an XML file and imported into RePhase for frequency corrections.
Delays are done in JRMC. You can add delays in the convolution's text *.cfg file or inside either of JRMC's Parametric Equalizers using the "Add Delay" option.
Verification is done with subsequent REW measurements.
"... I'm familiar with the REW group delay plots, but not these. ..."
I did not post any GROUP DELAY plots in the OP.
The multiple-trace plots are created using REW's "OVERLAYS" windows which allow one or more measurements to be plotted on the same graph.
I am using one of the latest beta versions of REW.
I am also using different FDW settings on each plot to emphasize/de-clutter the specific points trying to be presented (i.e. eliminate room reflections).
This is getting a little off topic, but here is the content of the 4 RePhase convolution files which make up the digital XOs, OB/Dipole sub rolloff compensation, phase and frequency corrections. I am using a multi-channel DAC to turn 2-channel stereo into 4-channel stereo which eliminates the downstream passive XO.
Low Pass Convolution files contains:
250Hz Low Pass XO filter
Low Shelf - OB/Dipole rolloff compensation
High Shelf - OB/Dipole rolloff compensation
Sub Phase correction - manual process
Sub Frequency correction - From REW's exported XML file
High Pass Convolution files contain:
250Hz High Pass XO filter
Maggie Phase correction - manual process
Maggie Frequency correction - From REW's exported XML file
Config file channel routing and conv file mapping:
Take input from channel 0 (left), apply convolution file 0 and send to output channel 0 (left high)
Take input from channel 1 (right), apply convolution file 1 and send to output channel 1 (right high)
Take input from channel 0 (left), apply convolution file 2 and send to output channel 6 (left low)
Take input from channel 1 (right), apply convolution file 3 and to send output channel 7 (right low)
Output channels 2, 3, 4 and 5 currently not used, but could be used for tri or quad amping.
not sure if many REW users are aware of this. The latest Beta revs provides a semi-auto alignment tool for phase/delay. Check it out.
Shumi and emailtim thanks for sharing all this useful information. Glad to hear the beta REW's got some new functions.
Very cool. Thanks for sharing the new feature.
I will have to learn it and give it a go.
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