Umik-1 and J-BoxII giving different curve above 4kHz

[Phil Pope]

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 voltage increased until curves overlaid each other. Checked the mics were both pointing directly at the centre of the horn. Speaker being measured it a large MEH. Mic position is 30cm from the front of horn. Red trace is the Umik-1, Blue is the J-Box. Why do the measurements diverge at high frequency?

 

[Wayne A. Pflughaupt]

For others checking this thread, the OP is not talking about the stand-alone karaoke system with the same name as the speaker calibration kit in question.

https://www.thanksbuyer.com/j-box-ii-audio-measurement-second-generation-speaker-frequency-response-curve-measurement-kit-support-for-justmls-rew-86413

Regards,
Wayne

 

[Phil Pope]

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

 

[Wayne A. Pflughaupt]

Is the SPL scale accurate?

Regards,
Wayne

 

[Phil Pope]

Is the SPL scale accurate?

Regards,
Wayne

No

 

[John Mulcahy]

Probably best attaching an mdat file with the two measurements, that will make it easier to compare them and their respective cal file responses.

 

[Phil Pope]

here is mdat file

 

[John Mulcahy]

Main contribution looks to be the UMIK's cal file.

 

[Phil Pope]

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?