Which measurement is correct ?

[Infra7]

Hello !

I was trying many hours to get consistent measurements with REW, i guess this was due to Windows issues. There are error messages appearing all the time, different ones. I am using REW with UMIK-2.

I was fighting a lot with "no input data", drivers were deleted automatically, the measurement won´t start, the mic was not recognized, clipping even at -25dBfs, you name it. I am sure these are Windows issues, i was setting up REW correctly ( and Windows, too, but yeah.. )

However, i got some measurements of my subwoofers, outside, i always got the identical measurement spot. It is an 8Ohm Sub, i was applying 2,83V measured with a true RMS Voltmeter and i was going to make 1w/1m measurements.

The measurements are different.

1-3 is the subwoofer measured today
4-6 is the same subwoofer measured yesterday

Both times at the exact same spot with exact same reflections, outside.


Which measurement is the correct one ? I would think that 4-6 are correct - but why are the other ones distorted ? What kind of phase is that ?


What went wrong with 1-3 ??


Thank you !


Kind regards

 

[John Mulcahy]

You would need to attach an mdat file rather than some images to get meaningful comments on the measurements. No input data and input selection reverting to default sounds like the mic is disconnecting, so USB cable length or connector issues.

 

[Infra7]

Hi,

thank you, of course i should add the mdat files. i have done so, now. The USB cable is the original one, the USB port is working. The cable and the mic are pretty new.

It would be great if you could have a look at those two, which one do you think is the correct measurement ? The low end cutoff is very different f.ex.


Thank you !