# trying to use the KRK Ergo with REQ ?



## LSP (May 8, 2010)

I'm just getting into using the Room EQ Wizard in my recording studio. I've recently added more bass traps, and added the KRK ergo room correction to finish "smoothing" out the peaks and/or valleys. I then want to "see" the before and after Ergo correction via Room EQ Wizard.

My problem is the fact that REQ will only let me select the analog outs from my Steinberg MR816 interface, and not the s/pdif outs, which are what is driving the Ergo unit, which in turn is driving my speakers. I can simply use the analog outs of the 816, and send those to the Ergo's analog ins, and all works fine. 

I was just wondering if there's a way to get REQ to recognize the s/pdif outs instead of the analog outs. In regards to the soundcard calibration; is there not a way to use the s/pdif outs and analog ins for this measurement. 

I'm just trying to keep things on an even playing field as possible. Since I monitor via s/pdif into the Ergo controller, I'd like to run a REQ test while also using s/pdif, otherwise, there's another A to D conversion which could likely skew the measurements.

Thanks,
Marc


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## Wayne A. Pflughaupt (Apr 13, 2006)

Welcome to the Forum, LSP!

As far as I know, you can’t use s/pidf with REW (John will correct me if I’m wrong). The only way REW can generate a calibration file for the sound card is via the line input and output jacks.

There’s no good reason why you couldn’t take your measurements through the 816’s analog outputs, then switch back to your regular connections for work. There’s no reason why an extra A/D stage should make a difference. If the A/D is that bad you shouldn’t be using it anyway. 

Regards,
Wayne


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## JohnM (Apr 11, 2006)

REW is not restricted from using digital outputs, though as Wayne says it becomes trickier to make a loopback calibration file. If REW is not ofeering a choice to select the S/PDIF output that suggests it is not included in the WDM driver output list. You could try setting S/PDIF as the default output for your PC in the Windows sound control panel and set REW up to use the default output.


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## LSP (May 8, 2010)

JohnM said:


> REW is not restricted from using digital outputs, though as Wayne says it becomes trickier to make a loopback calibration file. If REW is not ofeering a choice to select the S/PDIF output that suggests it is not included in the WDM driver output list. You could try setting S/PDIF as the default output for your PC in the Windows sound control panel and set REW up to use the default output.


If I can get the s/pdif's to show up in REW, how can I make the soundcard loopback, or is it even possible using the s/pdif outs. 

Also, when using a mic, instead of the db meter, how do I make a calibration file for the mic, as prompted in the software? I simply loaded the cal. file from the soundcard loop, but I've got a feeling that isn't what I was supposed to do. 

Thanks,
Marc


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## LSP (May 8, 2010)

Wayne A. Pflughaupt said:


> Welcome to the Forum, LSP!
> 
> As far as I know, you can’t use s/pidf with REW (John will correct me if I’m wrong). The only way REW can generate a calibration file for the sound card is via the line input and output jacks.
> 
> ...


The A/D in the Ergo controller is supposed to be pretty decent, I've just read where most everyone using it prefers the s/pdif in as opposed to the analog ins. Not sure if anyone actually has done a blind test though. 

So while I agree with you that it shouldn't make a difference, it would be nice just to take that out of the equation anyway.

Thanks,
Marc


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## Wayne A. Pflughaupt (Apr 13, 2006)

> ...how can I make the soundcard loopback, or is it even possible using the s/pdif outs.
> 
> I simply loaded the cal. file from the soundcard loop...


I’m confused. Did you get a sound card calibration file or not?




> Also, when using a mic, instead of the db meter, how do I make a calibration file for the mic, as prompted in the software?


You can create a calibration file for the mic yourself, if you have a frequency response graph from its manufacturer – see here.

Regards,
Wayne A. Pflughaupt


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## LSP (May 8, 2010)

Wayne A. Pflughaupt said:


> I’m confused. Did you get a sound card calibration file or not?
> 
> 
> You can create a calibration file for the mic yourself, if you have a frequency response graph from its manufacturer – see here.
> ...


I didn't "get" a sound card calibration file, I "created one" as per the instructions. Is this not the way I was supposed to do it?

I checked out the link; I don't yet know if the KRK measurement mic I am using has a frequency graph available. So far, the link isn't clear to me exactly HOW to turn the mic graph into a cal. file,.. I may be making it more difficult than it really is. 

To that end, is it necessary to have this mic file, moreover, will it skew the measurements if I don't have a mic cal. file. Like I said before, I thought I had to have one loaded, so I used the one that was created for the soundcard. Now I'm pretty sure that must have altered the measurements, no?


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## JohnM (Apr 11, 2006)

REW allows a cal file to be loaded for the soundcard, and a cal file to be loaded for the mic. The purpose of the cal files is to correct for the non-flat responses of soundcard and mic respectively. You don't have to load either file, and if you don't have the data for a file you definitely shouldn't load it! By specifying the soundcard cal for both soundcard and mic you end up with double correction applied for the soundcard's response, which is not what is needed. 

Without cal files you can't tell what parts of the frequency response are due to the system you are measuring and what parts are due to the response of the mic and soundcard. Soundcards are generally flat over the frequencies of interest for measurements, so no soundcard cal is not a big usse. The soundcard loopback measurement is partly to confirm the flat response and partly to check that the measurement setup is correct and giving valid results before making real measurements. Mics can vary significantly in their response, however. Even without any cal files you can see how the measurements are changing as you change things in the system.


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## LSP (May 8, 2010)

Thanks, that explains it.


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