# Focusrite 2i4 soundcard calibration



## Math (Aug 17, 2015)

Normally, I don't have issues with getting things to function properly but this is the graph I'm getting just after the sound card calibration. I'm using a Focusrite 2i4 with REW before I attempt to do anything in my actual home studio for room calibration.


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## Math (Aug 17, 2015)

*Re: REW distortion graph*

I tried using a sample rate of 96kHz and the graph resembles what the online manual suggests. I have attached the image. Can someone confirm function relative to the sample rate please? I was using 48000Hz before.


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## Math (Aug 17, 2015)

*Re: REW distortion graph*

Ok, I just tried this on a MOTU MKIII routed into a Mackie mixer and a sample rate of 96kHz. The graph looks great. So far, it seems suspect that the sample rate needs to be as high as it can to avoid artifacts due to limits of the DACs. This actually doesn't sit well with me as it makes no sense that a sample rate of 44.1 isn't sufficient enough.

Anyway, this is my last post on this issue until someone decides to follow up.


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## AudiocRaver (Jun 6, 2012)

*Re: REW distortion graph*



Math said:


> Normally, I don't have issues with getting things to function properly but this is the graph I'm getting just after the sound card calibration. I'm using a Focusrite 2i4 with REW before I attempt to do anything in my actual home studio for room calibration.
> View attachment 99273


That graph looks like you might have input monitoring enabled in the Focusrite control panel or mixer.



> I tried using a sample rate of 96kHz and the graph resembles what the online manual suggests. I have attached the image. Can someone confirm function relative to the sample rate please? I was using 48000Hz before.


Yes, that is what it should look like, and is a very good calibration curve.



Math said:


> Ok, I just tried this on a MOTU MKIII routed into a Mackie mixer and a sample rate of 96kHz. The graph looks great. So far, it seems suspect that the sample rate needs to be as high as it can to avoid artifacts due to limits of the DACs. This actually doesn't sit well with me as it makes no sense that a sample rate of 44.1 isn't sufficient enough.


It is not running at 96 kHz that is fixing anything. What you are seeing in your earlier graphs is not due to DAC limits or artifacts. A 44.1 kHz (we normally recommend 48 kHz, but 44.1 works fine) sample rate is sufficient. Check the input monitoring settings. Also check for a bad cable or connection, giving those noise bursts. Or a preamp channel of your Focusrite might be defective.


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## JohnM (Apr 11, 2006)

*Re: REW distortion graph*

The earlier plots look like the results of signal interruptions to me. Might have been marginal on buffering somewhere.


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## AudiocRaver (Jun 6, 2012)

*Re: REW distortion graph*



JohnM said:


> The earlier plots look like the results of signal interruptions to me. Might have been marginal on buffering somewhere.


 Yes, buffering, did not think of that. And that could be somewhat dependent upon sample rate as well.


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## Math (Aug 17, 2015)

*Re: REW distortion graph*

Thank you for the prompt responses. The Focusrite Scarlett 2i4 interface software is extremely limited as compared to their high end devices. There is no buffer adjustment setting but only a latency slider and sample rate pulldown. I rarely use portable gear but I do know this device has a good SNR and very quiet inputs, so I have it as an emergency backup for recording something into a computer. With the low SNR, you can see why I attempted to try out REW on it.

I suppose I may get different results on a desktop computer but I am not concerned in doing so as I was using this laptop/Scarlett setup to learn the process of room eq'ing with REW before attempting to go into my home studio with it.

For reference, the curve result for the MOTU 2408 MKIII, with same loopback cable, on my studio equipment is attached. 

Also, for the record, I got a similar graph with a Mackie mixer in the MOTU loopback chain. So, REW was especially helpful to show that the Mackie mixer does indeed add a -0.4db in the highs and lows.

Thank you for your responses and great efforts.


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## AudiocRaver (Jun 6, 2012)

*Re: REW distortion graph*



Math said:


> Thank you for the prompt responses. The Focusrite Scarlett 2i4 interface software is extremely limited as compared to their high end devices. There is no buffer adjustment setting but only a latency slider and sample rate pulldown. I rarely use portable gear but I do know this device has a good SNR and very quiet inputs, so I have it as an emergency backup for recording something into a computer. With the low SNR, you can see why I attempted to try out REW on it.
> 
> I suppose I may get different results on a desktop computer but I am not concerned in doing so as I was using this laptop/Scarlett setup to learn the process of room eq'ing with REW before attempting to go into my home studio with it.
> 
> ...


Is it correct to assume that you are using ASIO4ALL along with REW? The buffer size slider on its control panel, along with the latency slider on the Scarlett control panel, should give you the range you need to get clean measurements, after some experimentation. For REW use, my ASIO4ALL buffer size slider is always at 512 samples.


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## Math (Aug 17, 2015)

*Re: REW distortion graph*

Interesting...all my other posts and the replies are all gone including all the graphs and the one I just uploaded doesn't appear.

Anyway, no, I'm not using ASIO4ALL. I am using the current stable Focusrite Scarlett ASIO driver.

I'll try to upload the MOTU graph once more.


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## Math (Aug 17, 2015)

*Re: REW distortion graph*

Well...from the days of using stamps and missing letters, this is no big deal. 

As far as settings are concerned, you're saying that Asio4All will allow you to adjust buffer settings and display them. My solution was to just max out the sample rate. Either way, problem solved. My goal, ultimately, is to be able to eq any room for mixing orchestral music.


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## AudiocRaver (Jun 6, 2012)

*Re: REW distortion graph*



Math said:


> Well...from the days of using stamps and missing letters, this is no big deal.
> 
> As far as settings are concerned, you're saying that Asio4All will allow you to adjust buffer settings and display them. My solution was to just max out the sample rate. Either way, problem solved. My goal, ultimately, is to be able to eq any room for mixing orchestral music.


No argument, it gets the job done. I think it is useful to recognize where the problem lies, that the noise bursts were not due to a REW deficiency and that 48/44.1 kHz operation is an option if something pushes you that way in the future. _Go forth and prosper!_:sn:


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