Impedance measurement

lorrain

Registered
Thread Starter
Joined
Sep 28, 2020
Messages
11
Location
France
My AV System  
Main Amp
SONY
Hi,
In Impedance measurement, Rin (soundcard input impedance) is limited to 1Mohm but some soundcard have higher levels of impedance (more than 2Mohm for Focusrite Clarett in configuration Instrument Input for example) .
It would be nice to accept higher values
Eric
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
3,742
If you go through the calibration steps the input impedance value isn't used once the reference resistor measurement has been completed, in effect it is determined from the calibration results.
 

lorrain

Registered
Thread Starter
Joined
Sep 28, 2020
Messages
11
Location
France
My AV System  
Main Amp
SONY
Thank you very much for your answear, John.
I understand that if we calibrate in 2 steps only (without precison resistance) , the knowledge of Rin is useful and if we calibrate in 3 steps with the precision resistance, the knowledge Rin is not useful. Is it correct?
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
3,742
Yes, but the errors from not making a reference measurement will be far larger than the influence of such a high input impedance.
 
Top Bottom