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USB Mic Acoustic Timing

4K views 28 replies 2 participants last post by  JohnM 
#1 ·
Hi please can someone point me in the right direction cant seem to find instructions?

OS Windows XP

Thanks in advance
 
#7 · (Edited)
Hi John thank you.

Here is a step by step from Minidsp
Is this for HDMI?
https://www.minidsp.com/applications/auto-eq-with-rew/measuring-time-delay

In the preference soundcard panel I have set the following is this correct?
I have not got HDMI and are using Java

Output Device = O/S soundcard (not sure what it is called
Output = Default
Channel = Right

Input Device = UMIK
Input = Default
Channel = Left


Thanks again
 
#8 ·
As a general point, do not leave the input and output on default, set them to the option offered in the drop-down menu.

What are you trying to achieve by making measurements with a timing reference? If you can explain what you are trying to do it will be easier to understand whether the acoustic timing reference will help and, if so, how you should use it.
 
#14 ·
Use the 90 degree file if you point the mic straight up, use the zero degree file if you point the mic at the speaker you are measuring.

The timing reference allows different measurements to be compared or combined in magnitude and phase as they share a common timing reference.
 
#15 ·
Thanks John

I measured all speakers and they all said -200mm delay (in the info panel), except for the left speaker (which is the reference channel). It read -750mm, but when re-measured it also said -200mm, re-measured again and back to -750mm, what could this be?

Thanks again
 
#21 ·
Thanks John

It seems to be sometimes a smaller negative peak then a larger negative peak is this normal?

I have looked back on other measurements and sometimes the biggest peak has gone from negative to positive with absolutely nothing changing other than possibly mics or postioing. Im confused why this could happen

I'm I doing something wrong?

Thanks again
 
#25 ·
Hi John I have checked the polarity and it is connected correctly but the graphs shows incorrect polarity.

I have swapped the wires and polarity is good now, according to the graphs

Is it common that the internal wiring has been incorrectly wired?

Sorry at the moment I cant post files

Thanks again
 
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