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Discussion Starter #1
Hello, is there a way to export only phase data from a measurement? I tried to export the minimum phase "Measurement as text" , but i get the spl data also. What i need is an impulse response as wav or text which has the minimum phase data of the measurement but flat frequency response. Then i can create a time reversed impulse of the measurement which i will use for corrections (example to compensate high pass behaviour of a subwoofer).

Thanks :smile:
 

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If I understand; you intend to use a music player with convolver to achieve phase correction. That way some, or all, the phase rotation of the SW will be removed?

If that is your objective then 'rePhase' software can be used create the FIR filter you need. A rePhase filter can be created using an exported REW response measurement of your audio system. Use the text file export option. rephase allows us to create a phase correction FIR filter without any impact to SPL. rePhase can optionally be used for more complicated FIR filter designs if we want to filter the SPL also. I just use to create a phase correction filter that I use in Foobar2000.
 

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Discussion Starter #3
Yes you are right, that's my intention... but what i need is just to export the measurement done with rew as phase response alone with flat amplitude. I know rePhase only allow me to create a new impulse but it doesn't let me export the time reversed impulse of the rew measurement.
 

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Why not use rePhase to create the phase correction filter directly? That is what I do. It basically does the time reversal automatically when the filter is created.
 

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Discussion Starter #5
Becauase it requires too much time to create another impulse with the same phase in rePhase... when i can get it directly from rew..
 

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Another Filter? I must not understand the situation and objective.

My approach is to measure 20-20k response in REW (SWs+MR+TW) and export the FDW response as .txt. Then, load that into rePhase to create the phase correction filter. That is then applied as a mono filter in Foo_convolve. Thus both channels are corrected for phase.

If you explain your situation I may be able to help.

Phase response of my setup measured at LP Vs Phase response with rePhase FIR Filter active:
Phase Vs Corrected Phase.PNG
 

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Discussion Starter #7
When i load txt file in rephase, it doesn't make an automatic correction of the phase... it only allow me to use standard filters like (1st order, 2nd order, 24lr, closed or vented box compensation, ecc..). But my subwoofer high pass behaviour is not exactly as a simple 2nd order with Q 1,1 and fc 45 hz. What rephase is not able to do, is an automatic correction with phase reversal of the loaded file. I can choose to use many filters to flatten it, but it requires to much time for an accourate correction.

So if i have the possibility to export the phase alone, i will get a perfect phase compensation when i do the time reversal correction (using audacity) without engaging any other filter.
 

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Couldn't you just export the data with either comma or tab as the delimiter, load it into a spreadsheet and remove or modify whatever data you want?
 

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Sorry I couldn't help.
Yes, a text editor or spreadsheet works to get the text file requested, but I didn't seen how to get from there to the overall objective.
> Will audacity import a standard text file? I don't know how to do that.
> If not, is there a way to convert the text file into the 'RAW' audio format that Audacity will accept?
Thanks.
 

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you could do this in acourate but that's not a free piece of software

if you could create a linear phase magnitude response correction then you could convolve the measurement with that filter offline then import the resulting wav into audacity and reverse it
 
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