Dayton iMM-6 vs UMIK-1

[ManCaveAudio]

Hi, please find below the measurements of UMIK-1 vs iMM-6.
Configuration is as below.
AVR - Denon x4700h
Speaker - Polk ES-15 (L+R used for measurement)
Sub - SVS SB 3000

Only the challenge I faced was in Impulse measurement. It is not working as expected.

It does not measure the correct impulse with the use of acoustic time reference. I use it for speaker time alignment. Can anyone share their experience and guide how to measure the correct impulse with iMM-6?

Mic set-up as below.

I have connected iMM-6 with a USB audio driver and selected "USB PnP Sound Device" as input in REW.

I have used two different calibration files for iMM-6. One was the original file downloaded from the Dayton website and the Second one was the UMIK-1 file.

Sub-calibration data:

Blue: UMIK-1 with factory calibrated file
Green: iMM-6 with factory calibrated file
Yellow: iMM-6 with UMIK-1 calibration file

Speaker Calibration data (without sub):

Green: UMIK-1 with factory calibrated file
Red: iMM-6 with factory calibrated file
Purple: iMM-6 with UMIK-1 calibration file

I found that iMM-6 can measure below 10hz and comparing the price, it is a worthy investment. Differences are much acceptable considering the price to performance.

 

[sm52]

iMM-6 iMM-6 has the correct, positive polarity, UMIK-1 has negative polarity.

 

[ManCaveAudio]

iMM-6 iMM-6 has the correct, positive polarity, UMIK-1 has negative polarity.

I do not know how to check. Please guide. And how to correct it?

 

[sm52]

I don't know how to fix it so that both microphones show the same graphs. May provide both microphones to independent calibrators to obtain calibration files. Regarding microphone polarity, in the preferences/soundcard window, select Java drivers, the output device in the name should have Excl. Or select ASIO driver. Take one measurement with one microphone, the second with another. It’s better not a subwoofer, but a high-frequency driver, or midrange driver.

 

[ManCaveAudio]

I don't know how to fix it so that both microphones show the same graphs. May provide both microphones to independent calibrators to obtain calibration files. Regarding microphone polarity, in the preferences/soundcard window, select Java drivers, the output device in the name should have Excl. Or select ASIO driver. Take one measurement with one microphone, the second with another. It’s better not a subwoofer, but a high-frequency driver, or midrange driver.

Thanks for your support, I am new in this REW or calibration world.

May I ask how and at what point you find reverse polarity which I am not able to see or understood. Your input will help me a lot in my learning journey.

 

[sm52]

If you compare the 4th and 5th measurements, one microphone and another, compare their impulses, then they are the same, only inverted relative to the time axis, the X axis. To see this, click on the Overlays button in the main window, then the Impuls tab, Mark measurements 4 and 5, uncheck the rest. At the top left, switch to % when the mouse pointer is on the graph field, at the top right, click the gear icon and check Plot normalized. Increase the scale of the graphs along the X axis so that one division is 5m. Move along the X axis to get to time stamp 0.

 

[ManCaveAudio]

If you compare the 4th and 5th measurements, one microphone and another, compare their impulses, then they are the same, only inverted relative to the time axis, the X axis. To see this, click on the Overlays button in the main window, then the Impuls tab, Mark measurements 4 and 5, uncheck the rest. At the top left, switch to % when the mouse pointer is on the graph field, at the top right, click the gear icon and check Plot normalized. Increase the scale of the graphs along the X axis so that one division is 5m. Move along the X axis to get to time stamp 0.

Ok, thanks for your valuable inputs and help. I will raise the ticket to MiniDSP for ratification.

 

[ManCaveAudio]

@Travis Ballstadt