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Post by marcl on Mar 12, 2023 11:34:51 GMT -5
This is brilliant ... it's what we've always wanted! Here is how to use REW to measure Atmos channels! Watch very carefully. There are specific steps to disable ASIO and measure From File. You load the .WAV file after selecting From File in the Measurement screen. Then you separately play the .mp4 file using Windows Media Player or whatever you have (i.e. you don't play the .mp4 files from within REW). REW will wait for the chirp and record the sweep. You get all the usual data. Brilliant! Very cool! So basically we need to disallow REW from taking control of the sweep and play one manually. So when we click PLAY in REW it's just listening. Neato! as Herman Munster used to say. Now I gotta figure out how to do this with a Mac. Yes, exactly! |
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ttocs
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Post by ttocs on Mar 12, 2023 12:12:29 GMT -5
Very cool! So basically we need to disallow REW from taking control of the sweep and play one manually. So when we click PLAY in REW it's just listening. Neato! as Herman Munster used to say. Now I gotta figure out how to do this with a Mac. Yes, exactly! Easier than I thought it would be!!! With my Mac mini, all I did was to que up the file I wanted - blah_blah_blah_TFR.mp4 - in QuickTime Player, open the MEASURE window, click on PLAYBACK: FROM FILE and select the 1MMeasureSweep_0_to_24000_-12_dBFS_48k_Float_L_refR.wav, then click START and then play the mp4 file in QuickTime Player and sit back and let the process play out. THIS IS FRIKIN' COOL MARC!!!! Thanks!!!! edit: But, this took valuable time away from my deadline work I need to have complete by bedtime tonight! So, stop distracting me with shiny objects!! |
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Post by marcl on Mar 12, 2023 16:20:18 GMT -5
Easier than I thought it would be!!! With my Mac mini, all I did was to que up the file I wanted - blah_blah_blah_TFR.mp4 - in QuickTime Player, open the MEASURE window, click on PLAYBACK: FROM FILE and select the 1MMeasureSweep_0_to_24000_-12_dBFS_48k_Float_L_refR.wav, then click START and then play the mp4 file in QuickTime Player and sit back and let the process play out. THIS IS FRIKIN' COOL MARC!!!! Thanks!!!! edit: But, this took valuable time away from my deadline work I need to have complete by bedtime tonight! So, stop distracting me with shiny objects!! And that guy does some CRAZY stuff in REW that I had no idea it could do ... in this and his other videos. He's in the Audyssey ecosystem and a lot of what he does is not relevant to Dirac where we can't adjust delays, etc. But otherwise there could be some use in how he determines level adjustments. He has a link below the video to the "early access" REW 5.20.14 with different UI and some of the new features. |
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ttocs
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Post by ttocs on Mar 12, 2023 17:57:08 GMT -5
BTW marcl I don't know if you noticed, but in one of the last versions, don't recall which, it's now possible to finally turn off Tool Tips! |
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Post by thompson12 on Mar 13, 2023 18:16:45 GMT -5
This is brilliant ... it's what we've always wanted! Here is how to use REW to measure Atmos channels! First, here's a video that tells you exactly how to do it. There's a lot that does not apply to us as we use Emotiva gear and Dirac, but the Atmos part starts at 00:22:46 In order to do the measurements you need the .WAV and .mp4 files located here: drive.google.com/file/d/1APNO_yTseoPoBoyfwyjGLBTFat8g20_4/viewWatch very carefully. There are specific steps to disable ASIO and measure From File. You load the .WAV file after selecting From File in the Measurement screen. Then you separately play the .mp4 file using Windows Media Player or whatever you have (i.e. you don't play the .mp4 files from within REW). REW will wait for the chirp and record the sweep. You get all the usual data. Brilliant! Here's the response of my Atmos Tops - Magnepan MMGW Front, Polk OWM5 Rear - with crossovers at 120Hz ... along with all the other channels measured with the usual method. Psychoacoustic Smoothing. View AttachmentNice, I watched and enjoyed you guys zoom meetings maybe you guys can do a zoom meeting and go through this process and setup using an XMC\RMC. Mitch |
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Post by ttocs on Mar 13, 2023 18:28:06 GMT -5
This is brilliant ... it's what we've always wanted! Here is how to use REW to measure Atmos channels! First, here's a video that tells you exactly how to do it. There's a lot that does not apply to us as we use Emotiva gear and Dirac, but the Atmos part starts at 00:22:46 In order to do the measurements you need the .WAV and .mp4 files located here: drive.google.com/file/d/1APNO_yTseoPoBoyfwyjGLBTFat8g20_4/viewWatch very carefully. There are specific steps to disable ASIO and measure From File. You load the .WAV file after selecting From File in the Measurement screen. Then you separately play the .mp4 file using Windows Media Player or whatever you have (i.e. you don't play the .mp4 files from within REW). REW will wait for the chirp and record the sweep. You get all the usual data. Brilliant! Here's the response of my Atmos Tops - Magnepan MMGW Front, Polk OWM5 Rear - with crossovers at 120Hz ... along with all the other channels measured with the usual method. Psychoacoustic Smoothing. View AttachmentNice, I watched and enjoyed you guys zoom meetings maybe you guys can do a zoom meeting and go through this process and setup using an XMC\RMC. Mitch I'm game! |
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Post by marcl on Mar 14, 2023 6:21:15 GMT -5
A little note on this method. When I first did the four tops I used this method, then went back to the usual way to measure the other speakers. If you want to compare things like impulse timing, this doesn't work. I went back and did a whole set of all 12 speakers using these external files and it worked great. Only limitation is the sweeps only go down to 20Hz. They are 1M Length though which is good for S/N ... I think earlier versions from a few years ago were shorter Length. Here are my Frequency Response, Impulse Response and Music Clarity for all channels.    |
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Post by Jean Genie on Mar 14, 2023 8:05:10 GMT -5
A little note on this method. When I first did the four tops I used this method, then went back to the usual way to measure the other speakers. If you want to compare things like impulse timing, this doesn't work. I went back and did a whole set of all 12 speakers using these external files and it worked great. Only limitation is the sweeps only go down to 20Hz. They are 1M Length though which is good for S/N ... I think earlier versions from a few years ago were shorter Length. Here are my Frequency Response, Impulse Response and Music Clarity for all channels. View AttachmentView AttachmentView AttachmentDid you use this track?🎼😎 m.youtube.com/watch?v=oZLG9MV5GvQ |
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Post by marcl on Mar 14, 2023 8:06:50 GMT -5
A little note on this method. When I first did the four tops I used this method, then went back to the usual way to measure the other speakers. If you want to compare things like impulse timing, this doesn't work. I went back and did a whole set of all 12 speakers using these external files and it worked great. Only limitation is the sweeps only go down to 20Hz. They are 1M Length though which is good for S/N ... I think earlier versions from a few years ago were shorter Length. Here are my Frequency Response, Impulse Response and Music Clarity for all channels. View AttachmentView AttachmentView AttachmentDid you use this track?🎼😎 m.youtube.com/watch?v=oZLG9MV5GvQEvery time I typed "the four tops" I thought ... "what's a song to go with this?"  |
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Post by thompson12 on Mar 18, 2023 20:42:39 GMT -5
 Nice, I watched and enjoyed you guys zoom meetings maybe you guys can do a zoom meeting and go through this process and setup using an XMC\RMC. Mitch I'm game! Good evening all. So I'm trying to time align my speakers using the impulse response the way OCA guy showed but my surround come in at 3.97ms @ 4.5ft and 1.16ms @ 3.79ft before the other speakers How would I align these with the other. Mitch |
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Post by thompson12 on Mar 18, 2023 20:48:57 GMT -5
I tried adding delay to the center but it stays at 0u
Mitch
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Post by marcl on Mar 19, 2023 0:56:09 GMT -5
I tried adding delay to the center but it stays at 0u Mitch A couple questions: - Are entering the distances in the User Slot in the Preset, as the difference between what you physically measured (with a tape measure) and the REW measurement?
- Are you NOT going to use Dirac?
- Are you using the Acoustic Timing Reference in REW, like the Center channel (output 3 in REW)?
If you are going to use Dirac, you don't need to do this. Dirac will set the delays and these settings will have no effect. But it looks to me from the fact that you did something to the Center channel and the impulse response didn't change, that you may not be using the Acoustic Timing Reference, or it isn't working. Do you hear a chirp before and after your measurement for each channel?
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Post by thompson12 on Mar 19, 2023 5:17:07 GMT -5
Thanks marcl I forgot step one center channel setup.
1. I did not enter anything in the presets before running any measurements that's probably the problem.
2. Just playing around trying to learn this stuff without dirac and see the differences and affects.
3. Yes I did have acoustic timing reference turned on #3 center channel. I'll put the distance in presets #3 and try again.
Mitch
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Post by marcl on Mar 19, 2023 7:14:20 GMT -5
Thanks marcl I forgot step one center channel setup. 1. I did not enter anything in the presets before running any measurements that's probably the problem. 2. Just playing around trying to learn this stuff without dirac and see the differences and affects. 3. Yes I did have acoustic timing reference turned on #3 center channel. I'll put the distance in presets #3 and try again. Mitch Okay that sounds good. Yes, start by putting in the actual distances and do the measurements and see if the timing is off. Then you can fine tune the alignment differences (which should be very small) using the impulse measurements. |
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Post by LCSeminole on Mar 19, 2023 8:49:25 GMT -5
It’s been quite some time since I used REW, in prehistoric times since using it for the UMC-200, and was just getting the basis then. I’m going to try and make some time(tall order)to catch by watching the three videos at the beginning of this thread and then possibly joining you guys in a future zoom, hopefully!
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cawgijoe
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Post by cawgijoe on Mar 19, 2023 10:13:58 GMT -5
I’ve never used REW, but will view the posted videos and hopefully get a chance to play. For sure when I retire end of next year!
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Post by thompson12 on Mar 19, 2023 15:32:47 GMT -5
Thanks marcl I forgot step one center channel setup. 1. I did not enter anything in the presets before running any measurements that's probably the problem. 2. Just playing around trying to learn this stuff without dirac and see the differences and affects. 3. Yes I did have acoustic timing reference turned on #3 center channel. I'll put the distance in presets #3 and try again. Mitch Okay that sounds good. Yes, start by putting in the actual distances and do the measurements and see if the timing is off. Then you can fine tune the alignment differences (which should be very small) using the impulse measurements. Ok sounds good I'll try it as soon as I get a chance and post how it turns out. Thanks marcl Mitch |
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Post by thompson12 on Mar 19, 2023 20:37:48 GMT -5
Thanks marcl I forgot step one center channel setup. 1. I did not enter anything in the presets before running any measurements that's probably the problem. 2. Just playing around trying to learn this stuff without dirac and see the differences and affects. 3. Yes I did have acoustic timing reference turned on #3 center channel. I'll put the distance in presets #3 and try again. Mitch Okay that sounds good. Yes, start by putting in the actual distances and do the measurements and see if the timing is off. Then you can fine tune the alignment differences (which should be very small) using the impulse measurements. Ok that was it I put distance in and ran the measurements again I got them close the furthest one is less than a half inch off.    Mitch |
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Post by thompson12 on Mar 19, 2023 20:49:04 GMT -5
I think I may have to do them again I lowered the crossovers to 40 but never turned the subs off. Will that affect the impulse and time alignment?
Mitch
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Post by marcl on Mar 20, 2023 1:06:43 GMT -5
I think I may have to do them again I lowered the crossovers to 40 but never turned the subs off. Will that affect the impulse and time alignment? Mitch Okay getting closer. A couple things ... Your right surround impulse has a big pre-ring before the peak. Looking at that, it definitely has a negative polarity. So first thing would be to look at each impulse and look at the first movement of the wave ... all of them should start out going positive. The subs will have a much slower rolling impulse response, but it's still important to be sure they start in the positive direction. Here's an example of the subs (orange) aligned with the other speakers. This is with Dirac so the impulse responses are corrected and precisely aligned.  Here's an example (no Dirac) of two speakers that are not aligned to 0.0, and not aligned to each other, and both with negative polarity. But note they are not even 1ms from 0.0 ... only 9 inches or so in terms of distance.  The other thing is that pre-ring .... not sure what would cause that but assuming your surrounds are the same type of speaker and similar distance from the MLP, either there's something wrong with the measurement or something odd about the speaker. You don't have to turn the subs off. The way REW does the impulse calculation it weighs the higher frequencies more than low. So for the purpose of alignment of timing the subs don't matter, as far as their inclusion as bass management to the small speakers. But you do want to measurement subs for the purpose of alignment and checking polarity. |
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