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Discussion Starter · #1 ·
HI

I have a 2.2 (dual sub) setup. Im using JRiver Media Center 64 bit convolution feature with REW. JRiver seems only to take a single convolution file, but I would like to do corrections at the individual speaker level.. My question is: How do I do corrections on a per speaker basis and then also a master correction on top of that?

In other words: I would like to measure and correct each speaker (=4 speakers). After I have each speaker adjusted, using the 4 correction filters, I would like to measure the combined (corrected) response in REW and make an additional filter for further (combined speaker) adjustments.

Can this be done using REW and Jriver MC?

If not, this may be why some people are using Aidiolense, which can do the above. I much prefer working in REW and am trying to figure out how to combine multiple per speaker filters.

Thanks

Thanks
 

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ccclapp said:
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,and am trying to figure out how to combine multiple per speaker filters.

> Not exactly my cup of tea ( since there's no HTPC here ), but ;

TheLion said:
taken_from_HERE!

The used Convolver config is:


48000 8 8 0
0 0 0 0 0 0 0 0
3.6 3.6 3.9 0 1.1 1.3 0 0.1
C:\EQ\Referenz-3db\Left-3_48.wav
0
0.0
0.0
C:\EQ\Referenz-3db\Right-3_48.wav
0
1.0
1.0
C:\EQ\Referenz-3db\Center-3_48.wav
0
2.0
2.0
C:\EQ\Referenz-3db\LFE-3_48.wav
0
3.0
3.0
C:\EQ\Referenz-3db\Left_Back-3_48.wav
0
4.0
4.0
C:\EQ\Referenz-3db\Right_Back-3_48.wav
0
5.0
5.0
C:\EQ\Referenz-3db\Left_Surround-3_48.wav
0
6.0
6.0
C:\EQ\Referenz-3db\Right_Surround-3_48.wav
0
7.0
7.0
C:\EQ\Referenz-3db\Subwoofer-3_48.wav
0
0.0 1.0 2.0 4.0 5.0 6.0 7.0
3.0


As you can see I use the delay feature (third line) and specify the channel delays in x.x ms. This is highly relevant for the XO to the sub (the sub delay is set with internal sub DSP) and different handling of those decimal delay parameters may be a reason for the difference?!
> It seems obvious ( to me , at least ) that to implement multi-channel convolving ( within either MediaCenter or ConvolverVST ) one needs to learn how to "script" a proper "configuration file" for MC ( or Convolver ) to work from ( see the above example ) .
> This script directs the "calls" to the individual EQ ( correction ) files ( see above ) to be convolved .

> You've got some homework to do !

:)
 

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Caleb,

> So,,, how's the homework going ? :innocent: :whistling:

> Hopefully, by now you have read Convolver's info page demonstrating some examples for various "Configuration Files" for convolverVST to reference .
> Notice the particulars in this pic ;



> Note, that both Convolver and JRiver's "Media Center" use the same formatting within the custom "configuration file" ( that is up to you to create ) .
> Understanding how to create ( script/write ) a custom configuration file ( saved as a text file ) for one convolver allows one to use the same config file for the other convolver ( MC or convolverVST ) since the formatting is the same between both .

> Within either convolution engine ( MC or ConvolverVST ) , one can directly reference the .wave file to be convolved //// or //// reference the configuration file ( that in turn references individual/multiple .wave files to be convolved ) .

:)

PS #1 : This stuff , is still well within the bleeding edge of the Bell Curve for those who wish to become "early adopters" . As a consequence, a lot of things ( like creating configuration files ) are left up to the end user to figure out /// a more "refined" program aimed at a mass market would have these parts simplified .

PS #2 : You might be better off to stick with convolverVST if your computer is just 32 bit ( since MediaCenter's convolution engine is strickly 64 bit and as a consequence, puts more demand on a computers CPU ) .
 

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Discussion Starter · #4 ·
Hi Earl. Thanks very much for your two replies. Sorry to have been distracted for a few days and not to have replied back to you...

"Not exactly my cup of tea ( since there's no HTPC here )"...

...No, I'm not doing HTPC either. I have two mains and two subs and a mytek 8x192 highend DAC, primarily for music. Integrating the subs and a tough room leads me to DRC. At this point, I prefer a more hands-on approach to a push-the-button solution. As such, I will effectively be doing 2 x 2 X/O's plusover all room correction. After the less automated REW approach, I will be in a better position to evaluate/compare other options like Audiolense/Acourate, etc.

"The used Convolver config is:"...

...while I have not yet created my config file, I now understand what needs to be done. Thanks for the links, that's helpful.


One more question, if I may:

To see the results of my incremental adjustment steps, e.g. impact of XO's and then room correction, with/without time-domain changes, etc...I need to apply my various corrections to the REW measurement sweep and compare the before/after measurements (and listening). I know I can do this by recording sweeps and playing back via JRMC, etc, etc and using REW RTA set to Pink PN. However, that will only give me frequency responce data, not waterfalls, excess group delay, etc. I also know in JRMC, I can use the loopback feature to play the live REW measurement sweep through JRMC with one or more correction filters applied.

My question is: Will additional delay, phase change, etc possibly caused by the JRMC loopback, yield misleading REW measurements? If so, I suppose one option is to run ALL REW measurements through JRMC, so before/after are equally impacted and the comparison would be more meaningful. Do you have any wisdom on this?

Thanks
 

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Caleb said:
,,,,,,,,,,,,,,,,,My question is: Will additional delay, phase change, etc possibly caused by the JRMC loopback, yield misleading REW measurements? If so, I suppose one option is to run ALL REW measurements through JRMC, so before/after are equally impacted and the comparison would be more meaningful. Do you have any wisdom on this?
> I'll respond a little bit later ( it may even be tomorrow ) with a post that I hope has some wisdom in it .

:sn:
 

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Discussion Starter · #7 ·
To see the results of my incremental adjustment steps, e.g. impact of XO's and then room correction, with/without time-domain changes, etc...I need to apply my various corrections to the REW measurement sweep and compare the before/after measurements (and listening). I know I can do this by recording sweeps and playing back via JRMC, etc, etc and using REW RTA set to Pink PN. However, that will only give me frequency responce data, not waterfalls, excess group delay, etc. I also know in JRMC, I can use the loopback feature to play the live REW measurement sweep through JRMC with one or more correction filters applied.

My question is: Will additional delay, phase change, etc possibly caused by the JRMC loopback, yield misleading REW measurements? If so, I suppose one option is to run ALL REW measurements through JRMC, so before/after are equally impacted and the comparison would be more meaningful. Do you have any wisdom on this?
Thanks
...partially answering my own question above, I just now I confirmed I get a good signal from REW through MC in loopback (no stutters, clicks, pops). MC Playback Options is setto WASPI Eventstyle with hardware buffer at anything from 10-100 ms to my firewire Mytek 8x192 DAC. If I use ASIO instead of WASPI I get stutter. I assume I should use the least possible buffer, or does it matter?

Correct me if I'm wrong, but I also assume it doesn't matter what sound device should be set to default for REW to play on (to be looped back to MC).

Does anyone know REW well enough to suggest what graph I should inspect to determine of Im getting any additional delay, phase shifts, etc from loopback that harms by before/after comparison?

Also, does anyone know why most have said we can only use REW RTA, not MC loopback, to inspect before vs after results?? It seems to me the way to do it is via MC loopback, unless there are issues that arent apparent.

PS: Since I posted this elsewhere, Ill report these findings there as well..

Thanks
 
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