Problem Calibration

[Dante Cry]

Hello everyone,

I allow myself to write here because I find myself facing a problem that I can not understand or solve.

I wish to make the acoustic measurements of my home studio, only I can not properly calibrate my sound card with REW.


Here is my problem:


My input gain level is much too low (-37 dbfs) while I have the input knob completely thoroughly.


So, if I drop my output level to -37dbfs, I end up with a curve filled with 'peaks' and not smooth.


However, if I balance with the out using the knob: volume monitoring, I find a flat curve but the signal is no longer "In" but "In + Out".


This is a problem for me at the time of sound because I end up with a very loud sound volume at the time of measurement.

Is this normal?

So, I do not know what to do, or how to do it. I do not know if I understand how to do the manipulation or if there is a problem with my sound card.


My sound card is the focusrite 18i20. I use TRS for loopback. REW V5.18.


If anyone can save me, it'll be amazing!


I am French and it may be that there is something that I didn't understand in the record of REW or an answer that I didn't see on the forum for the same problem ... be indulgent, please .

Sorry for my English.

I thank you all,

Regards,

Dante

 

[Wayne A. Pflughaupt]

Perhaps John has some ideas, but unfortunately Dante, you may be in what I call the “fancy sound card twilight zone.” Basically, simple interfaces work best with REW. This post explains.

Regards,
Wayne

 

[Dante Cry]

Hello Wayne.
Really thank you for your message
I will translate all that!

Regards,
Dante

 

[John Mulcahy]

You must make sure monitoring is off, we do not want any of the input signal feeding back to the output. One of the reasons to do soundcard calibration is to check monitoring is off.

I guess that levels and routing are controlled by your software mixer, the problem may lie in the mixer settings somewhere. It is odd to have low input level with a line level connection.

 

[Dante Cry]

Hello John,
Thank you for your reply.

yes I indeed 'mutated' the micro input track in the mix control.

I looked in the mix control and I didn't find anything at the level of the routing.

I don't understand because a friend tried yesterday at his home with his Focusrite scarlet solo and we have almost the same result. Knob input gain completely thoroughly, it is left with -34 dbfs (with Java).
He is forced to open the volume monitor knob to enhance the IN.

Concretely, if I open the 2 knobs, is my calibration just right?

I do not know how to handle the 2 knobs.

Really, thank you again for your future response and sorry to bother you.

Thank you,
Dante

 

[John Mulcahy]

It looks like you have selected the monitor as the output, so you will need to use the monitor volume to set the output level. Have you tried using other outputs instead of the monitor?

 

[Dante Cry]

Hello John,
Sorry for my late response.

I tried to change output (I tried all the outputs) and indeed, I go from -37dbf to -22 dbfs!

Only my peakmeter is really high.
If I caliber at -22dbfs, I end up with a headroom in the red. I am forced to lower my output level to -28dbfs for that my input not peak.

Even if I drop the output level, I end up with this line.

Another opinion regarding this information?

I give you screens so that you can better understand.

I thank you for your informations.

Dante

 

[John Mulcahy]

I don't know anything about the Scarlett Mixcontrol, sorry, but two things look strange:

1. The REW input meters show signal on both mic1 and mic 2, but REW is only putting a signal on the Line 3 output, so something else is routing a signal into mic 2
2. In the mixcontrol window it looks like you have configured mix1 L to go to both Line 3 and Line 7 outputs, but mix1 L is the input signals from mic1/mic2, so you appear to have mixcontrol set up to create a feedback loop.

The only thing going to the output should be the signal from REW. Do not route anything else to the output.

 

[Dante Cry]

Hello,
I did as you told me:

- I removed the second cable so as not to have another signal.

- I disabled all the routes specified by default.

I find exactly the same thing. I have a signal in fullmix1 when I remove the mute.


If you know a sound card, entry-level, which is sure to work with the software, I want to have the info please.

I'm not very good at it all and I'd rather it all work, rather than spending more time searching rather than working.

If you can advise me, thank you very much.

Dante

 

[John Mulcahy]

The simplest route is usually a USB mic like the miniDSP UMIK-1. Otherwise the built-in audio output and input of a PC are also fine to use, but with an analog mic you'll usually need an interface with a mic preamp and phantom power to be able to feed the PC line in. There are some other suggestions on the REW page.

 

[Dante Cry]

Thank You John