Calibration Set Up Channels

[Sonder]

Hello, I am trying to follow the calibration setup, but something is very odd.

I am using a 2-channel Focusrite interface, when I follow the calibration instructions it says to connect the loopback to channel 2 when I do this there is no signal when I try and measure, it only seems to work when it is on channel 1?

Could someone tell me what I am doing wrong here?

Many thanks

 

[John Mulcahy]

Calibration is for the measurement input, so connect the output to the measurement input, channel 1 in this case. When using a loopback as a timing reference (not applicable to calibration) it goes to the other input channel.

 

[Sonder]

Thanks for the reply.

But I need the loopback to measure the input channel, so do I measure ch1 with the loopback, then disconnect and put it in ch2 as the reference?

 

[John Mulcahy]

Yes.

 

[Sonder]

Thanks, I understand now, I wonder if it would be good to state this in the instructions for calibration, as it does not say that here;

The audio interface is measured with an external loopback connected to allow its frequency response to be determined and saved as a calibration file. This response is subtracted when subsequent measurements are made, eliminating the interface's own response. The loopback connection goes from the output channel that will be used for measurement (usually the Right channel of the Line output) to the input channel that will be used (usually the Right channel of the line input).

Please connect the loopback now and press Next when it has been connected or Cancel to quit.

 

[John Mulcahy]

Isn't that exactly what it says?

 

[Sonder]

Maybe it's just me not understanding it.

It says output from right to input right, shouldn't it be output right to input left (then disconnect from input left and put into input right for timing reference loopback).

 

[John Mulcahy]

The choice of which channels to use as measurement output and input is up to you. A loopback is not needed for measurement, unless you intend to use it as a timing reference.

 

[Sonder]

I still think it's confusing, how an ever, great software, thank you.

"The loopback connection goes from the output channel that will be used for measurement (usually the Right channel of the Line output) to the input channel that will be used (usually the Right channel of the line input)"