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Discussion Starter · #3 · (Edited)
Sorry if I was unclear…
I am trying to use REW instead of other software because the support for the DCX2496 filters…*at the same time*

If I display the overlay window, is there a way to show 'minimum phase' for selected measurements based on an individual measurement / time base of these ?
I.e. I show a minimum phase of the midrange system, and also display the highrange system minimum phase in the overlay window

> for time aligning 'thru crossover'

Thank you very much
and best regards

Klaus
 

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Discussion Starter · #8 ·
I use the same rig as with Smaart,
1 soundcard ch = reference, 1 soundcard channel = measuring output / input.
So this should be ok…. not ? ( all measurements are then correlated time / phase wise, not ? )
Do I have to set anything else ?
> the wrapped phases in overlay woud be nice to be displayed as minimal phases so one can overlap phases in the processor settings on regions or crossover points…
Aligning 'just' by IR isn't what I'm trying to do, but exact phase overlapping…
Thanks a lot

Klaus
 

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Discussion Starter · #11 ·
Yeah, thanks a lot John, step by step is best to me...
I had it set to 'no timing….:D
I'll repeat when I get to the club…
Best regards

Klaus


Klaus,
Main Steps:
> Set REW 'loopback timing'/'Acoustic timing' depending on XLR/USB mic.
> Measure MR driver and TW driver
> Select the TW measurement/impulse chart
> Open the 'controls' panel
> Select 'Estimate IR Delay' Record the delay that is offered (ms).
> Select 'Shift IR' [The TW impulse will shift that amount back to near 0 ms]
> Select the MR measurement/impulse chart. In the 'controls' panel and enter the recorded offset value used for the TW IR into the 't=0 offset(ms):' entry box and select 'Apply'
[The MR IR will shift the same amount as the TW. The relative timing will be unchanged as they were both shifted the same distance.]

REW settings for phase analysis:
> Open the 'overlay/phase' graph panel.
> Set 1/48 octave filtering for both measurements.
> Activate the 'IR Windows' popup.
  • Enter 0.00 into the 'Window Reference Time' box
  • Check 'Add Frequency Dependent Window'
  • Enter '5' into 'Width in cycles' [A greater number often works fine. Using a lower number will start to distort the trace tails.]
  • Select 'Apply Windows to All'

The phase overlay graph now displays the correct relative phase between the MR and TW and should be easily read. If it is not clear then there was an error in this process.

If you shift the MR impulse location to find the offset need for proper phase tracking then it is necessary to again enter 0.00 into the 'Window Reference Time' box and select 'Apply'. Any IR shift requires resetting the 'window reference time' to 0.00 to assure the phase relationship will be correct.
 
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