Signal Generator - Calibrate Level - strange behaviour

Hi

I am using latest version 5.31.1 but seem to have replicated this problem with v5.19.
generating a sine wave with the Generator at 50Hz, switch it to Volts scale and press play to start the signal.
connecting multimeter to speaker outputs of my amplifier I get a reading of 1.7V.
Press the calibrate level button, type in 1.7 and press enter. the generator now says the level is 1.7V RMS
Shouldn't the level in the generator now track the level on the multimeter?
If I turn the generator up to 3V the multimeter only reads 2.83V - nearly 10% error.
Is this normal? Have I fundamentally misunderstood how this should work?
I've tried two different laptops, two different amps, headphone output and USB interface.

the calibrate function and volt function are only on the newer version. but on version 5.19 increasing the generator level by 10dB doesn't give 10dB rise in multimeter voltage.

the better one I have is a UNI-T UT60E multimeter. says it is trueRMS with a bandwidth of 40-400Hz. The signal I am generating for calibration is a 50Hz sine wave so it should be able to measure that accurately.
I have ordered a Multicomp Pro MP730678 to check whether my UNI-T is faulty but again it has 40-400Hz bandwidth. Surely I don't need to spend hundreds on a 20Hz-20kHz meter just to calibrate the voltage level?

nb just checked the UNI-T meter and it exceeds spec - consistent voltage reading from 20Hz-1kHz

DanDan said:

Phil, may I suggest you make a new post or question regarding what you are trying to do. If you are troubleshooting your REW rig, is suggest you start with the bare minimum. The onboard Line In and Out if possible. Adjust the OS levels to nominal or 0dB. Any old RMS AC Voltmeter should be reasonably accurate at a single sine frequency within it's range. You mentioned speaker outputs of your amplifier....... I would omit that from the chain of events.

Click to expand...

measuring the voltage on the headphone jack output I get exactly the same issue - the output voltage doesn't track the voltage in the generator. I have tried two different laptops, disabled every audio setting I can find that might be interfering, reinstalled the audio drivers. Waiting for a third multi-meter to arrive see if that solves it.

tried it at 400Hz and it seems a lot more accurate. calibrating then doubling the generator voltage i'm getting about 2% error rather than 10% or more. new multi meter is on its way so will try same with that one. Always assumed multimeters were most accurate at mains frequency 50Hz

I'm trying to measure the output voltage from my amplifier so I can do calibrated loudspeaker sensitivity measurements - so I need to use an external meter don't I? what do you mean by 'the Meter in REW'?