Recent content by Phil Pope

I changed the internal gain switch on my UMIK to do high volume measurements of subwoofers. amended the cal file to change the gain. could this have made it less accurate at high frequency?

thanks. the J-Box measurements seem to keep the same shape regardless of drive level whereas the Umik roll-off seems to be all over the place - which suggests there is something wrong with my Umik set up I guess. And the J-Box measurements are more in line with what I was expecting from...

thanks for looking at this. So the UMik cal file is incorrect? How can you tell it is the Umik cal file rather than the JBox cal file?

here is mdat file

No

just tried it again at a lower drive level. less of a difference but still there.

Hi not sure why I am getting different measurements. Umik-1 USB mic is set up with mic calibration file, headphone output goes to mixer and then to power amp. J-box II was set up according to instructions and mic calibration file loaded, aux output connected to mixer and power amp, REW output...

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'?

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

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...

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...

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.

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...