Calibrating for Focusrite Scarlett 8i8 (3rd Gen)

[madscene]

Trying to learn how to use REW for analyzing my home studio. I watched the youtube video from the REW website, and was trying to calibrate my Focusrite as he does with his Duet in that video. I used a balanced 1/4" to 1/4" from the right speaker out to input 2 on my Focusrite. (I didn't do anything with loopback because he didn't in the video and frankly I don't know what that is!). I seem to get some signal but as I try to turn it up to get to the recommended range, it doesn't change but suddenly at a certain point overloads and peaks. doesn't matter if I raise the input level, output level or fiddle with both. There's a point where it just pins to the top. Hopefully I'm not frying something... (I turn it down/off as quickly as possible when this happens).
Does anyone know what's going on or have experience creating a calibration file for the Focusrite? I noticed in the video he used a 1/4" to XLRM cable, but I thought the balanced 1/4" cable would also work?

 

[John Mulcahy]

There is some input monitoring active causing a feedback loop when gains are raised. You need to configure the Focusrite software so that only the signal from REW goes to the outputs, all the inputs should be muted for the output mix.

 

[madscene]

There is some input monitoring active causing a feedback loop when gains are raised. You need to configure the Focusrite software so that only the signal from REW goes to the outputs, all the inputs should be muted for the output mix.

Ah, I think I understand. The input is sending the signal right back out to the output... will see if I can fix that in the Focusrite control software. Thank you!

 

[DanDan]

@madscene an interface is likely to be flat within a dB or less, and with minuscule distortion or noise. I see no need for a Calibration file. As a beginner I would also advocate no loopback. If you ever need it you will know why.

 

[madscene]

@madscene an interface is likely to be flat within a dB or less, and with minuscule distortion or noise. I see no need for a Calibration file. As a beginner I would also advocate no loopback. If you ever need it you will know why.

I wondered about that (the need for calibrating) but since the video from the site said to, I thought I should. Anyway, @John Mulcahy was spot on. I thought I had tried muting the inputs but I think I probably muted all but the one I was testing, not realizing that of course it is feeding back into the output.

And that's what I figured about the loopback.

 

[John Mulcahy]

The main aim of the loopback cal these days is to pick up inadvertent monitoring, which it does very well.