Question regarding REW impedance measurement level difference error

[JalteJKR]

Hi

So today I put together an impedance testing rig for REW. I am pretty certain that I have put it together correctly according to the schematic REW supplies, but when I try to do the open circuit calibration I get the error that can be seen in the attached screenshot.

I have everything set as can be seen on the other picture, both inputs set to the exact same 12'o clock position and the headphone output set to give me about 20dB of headroom.

A thing that is confusing me is that it says "If the input channels have individual gain controls they need to be the same.", but the measurement input is passing through an 82ohm resistor that the reference input is not, so doesn't it make complete sense the the level on the measuring input will be lower? Can anyone explain this for me?

 

[Ukaniu]

I think setting input sensitivity other than max is problematic due to large uncertainty of this setting in middle positions.

 

[AllenB]

The 82ohms is not going to be significant against the input impedance.

 

[JalteJKR]

Thanks for the replies

I will try again with the gain set to max on both channels. I didn't think about the input impedance on my interface, but yes that is of course gonna make the 82 ohm resistor insignificant.

 

[1audio]

You should confirm that the SSL is in Hi-Z mode and not something like 150 Ohm mike mode (very obsolete but may still pop up somewhere).

 

[JohnPM]

Just do what the message says, play a test tone from the generator and tweak the gains until the levels match.