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Multi-Way Conventional loudspeakers with crossovers

rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
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Old 12th February 2017, 01:48 PM   #1771
mark100 is offline mark100  United States
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Quote:
Originally Posted by thierry38 View Post
Hi Mark,

Is it dot or comma for decimal separator ? (frequency domain file)
text header is removed ?

If you can show the file.(time domain)
Hi Thierry, don't know why, but tab separator works for frequency domain import, and space doesn't . But it works !

If I can get a wav impulse file to import , ALL systems go.

Don't know what you mean by show the time domain file...how do I show a wave? (Space separated works for txt impulse import.)

BTW, here's a screenshot of HOLM import of latest REW meas (FDW6 I think)...
This is using the jriver ID running 65k taps per channel.
Attached Images
File Type: jpg Holm 65K taps.JPG (194.6 KB, 321 views)
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Old 12th February 2017, 02:20 PM   #1772
BYRTT is offline BYRTT  Denmark
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by mark100 View Post
...BTW, here's a screenshot of HOLM import of latest REW meas (FDW6 I think)...
This is using the jriver ID running 65k taps per channel.
That is what i call by the book precision and great work, in that spot in space must sound fantastic and hope you get this kind of performance spread into wider area too.
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Old 12th February 2017, 07:21 PM   #1773
mark100 is offline mark100  United States
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Quote:
Originally Posted by BYRTT View Post
That is what i call by the book precision and great work, in that spot in space must sound fantastic and hope you get this kind of performance spread into wider area too.
Yep, textbook for one spot...that's too close to listen to haha...about 4ft.
It minimizes room reflections there....
(but certainly does sound dang good out in room

I wanted to get as close to ideal response as I could, because now, without moving mic etc, I'm taking the rePhase files that are in jriver's convolution running 65k taps per channel , and regenerating the exact same files at 6144 taps per channel, to run in the openDRCs.

Want to see how my two 'best current alternatives' measure and sound...

PS...thx for the kind words!
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Old 14th February 2017, 11:59 AM   #1774
Rokytheman is offline Rokytheman  Denmark
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Quote:
Originally Posted by Pano View Post
HOLMImpulse takes a different approach. By default it centers the impulse of each measurement. You can choose how it centers the, default is 1st peak, IIRC.

However, you can choose not to center the impulse, which would show you total delay. Or you can center the impulse on one measurement, say the midrange driver, then lock the time and see the offset of subsequent measurements. That would be similar to what REW is doing with the calibration.
Until know I have used Holm to export impulse responses, but Im not sure whether or not my method is best practice.

In Rephase i can see a decent flat phase, which is relatively easy to flatten out ie. no odd wrinkles except around the tuning point for the box (as should be). I guess this point to being a good basis measurement/impulse, but Im not sure how to best center the offset. I quess if the offset is not set as it should, the sound will not be as good as can be. I have tried different offset (both in Holm and Rephase)(can not remember the exact settings) - and there is clear audible difference - But when I do not now the best method/now how things are working, my testing is random. Off course my ears let me now if something is not right, but it is forth and back.

My system is multiway ie tweeter, mid/bass and subwoofer.

How do you guys export impulse response files from REW or Holm (would like to know methods in both) ready to import in Rephase => Ie what is the exact settings/methodology to do this? (there seems to be a low of variables to adjust). As I see it:
1) Setting the device up (settings in holm/REW)
2) Manipulate the specific measurement (Gating, offset, time zero locked etc) (holm/REW)
3) settings when exporting the impulse response (Holm/REW)

I have not found a good article about doing it right, before even working with Rephase.

Som screenshots would be very welcome- and I think that a lot of people would benefit from it (Guess I am not the only person who have not figured this process out).
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Old 15th February 2017, 03:40 PM   #1775
thierry38 is offline thierry38  France
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Hello,

it can be a long way to describe universal walktrough.

Use the measurement.txt file (frequency domain),file contains 3 columns (frequency---magnitude---phase).
drop out the text header (information) with any text editor .

more tricky operation is to get a proper/clean acoustic measurement

gating,try about 80~100ms on the left and right side of t=0,flat top window seems to working fine in every case,and 1/3 (or 1/6) octave smoothing.
or frequency dependent window (warning...).

to export from REW,as shown below.(take a look at the text delimter,(space))

Click the image to open in full size.

Last edited by thierry38; 15th February 2017 at 03:48 PM.
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Old 16th February 2017, 05:52 AM   #1776
diyaudnut is offline diyaudnut  United States
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Hi

My raw driver response measurements used loopback timing reference in REW.
All drivers were measured with the mic at 1m and at tweeter height.

Can the difference between "system delay" values reported by REW be used as the timing alignment delay between the drivers?
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Old 16th February 2017, 03:22 PM   #1777
mark100 is offline mark100  United States
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Quote:
Originally Posted by diyaudnut View Post
Hi

My raw driver response measurements used loopback timing reference in REW.
All drivers were measured with the mic at 1m and at tweeter height.

Can the difference between "system delay" values reported by REW be used as the timing alignment delay between the drivers?
Hi, Yes.

IME, loopback timing ref differences in raw measurements closely reflect physical offsets, providing lower freq drivers reach high enough to get a good timing "lock". You can tell a good "lock" by running several sweeps and seeing if the time delay stays consistent...

And then with the delays in place, if you use linear-phase xovers, timing should be very close to correct. Fine tune it, a few samples at a time, until you get the flattest phase line through x-over you can.

If use use minimum phase x-overs, you will need to do further timing work. But I don't know why you'ld use minimum phase x-over unless you are planning on an entire speaker summed phase correction,..... instead of driver by driver.
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Old 17th February 2017, 07:02 AM   #1778
diyaudnut is offline diyaudnut  United States
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Thanks Mark. This is indeed for a linear phase 4-way.
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Old 21st February 2017, 05:08 PM   #1779
Rokytheman is offline Rokytheman  Denmark
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Hi thierry38,

thank you!

Still not totally sure whether or not Im doing it right though
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Old 25th February 2017, 06:25 PM   #1780
sax512 is offline sax512
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Location: Virginia, USA
I moved this subject to its own thread, as I think it deserves its own space.
I also don't want to detract from the subject of this thread, as I was hoping for a couple quick links to products that managed to measure their phase directly, but it doesn't seem to be the case.

http://www.diyaudio.com/forums/equip...libration.html

Thank you all for your input and feel free to chime in in the new thread.
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