# Behringer ECM8000 measurement positioning help please.



## tattoo_Dan (Jan 17, 2009)

which direction to point a Behringer ECM8000 when measuring with REW in my HT ? 

towards the front speakers/sub ? 

or up at the ceiling ? 

or is it truly omnidirectional and it doesn't really matter ?

*it will be on an ear height stand in the center of my listening position*


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hey Dan,

You’ll find everything you need on that topic here.


Regards,
Wayne


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## tattoo_Dan (Jan 17, 2009)

thanks Wayne


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## Djnickuk (Mar 30, 2012)

A couple questions on mic orientation.

I understand that horizontal with 20 deg incline in preferred for fr measurements. Which is fine. I have a premium plus 8000.

But I have an issue when it comes to measuring the side speakers as they are at about 6 foot height. Meaning to point the mic at them the mic will be near 45 deg or perhaps higher. Which puts it in between horizontal and virticle. So what file should I use? Should I just point the mic to the ceiling in these measurements? 

Also, for the purpose of soley speaker distance measurements, I want to move the mic as little as possible so to give the most accurate results for each speaker. And the best way for this would be to leave the mic in a virtical position and complete a measurement for each speaker. As we are only measuring time of flight, really. The reflective portion of the sound should not screw with these results as the direct speaker sound will always hit the mic first?


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## Wayne A. Pflughaupt (Apr 13, 2006)

Djnickuk said:


> But I have an issue when it comes to measuring the side speakers as they are at about 6 foot height. Meaning to point the mic at them the mic will be near 45 deg or perhaps higher.


 Or, you could point the mic directly at the speaker, then _lower_ it 20 degrees. That would be a legitimate option of the speaker is significantly higher than the mic.




> The reflective portion of the sound should not screw with these results as the direct speaker sound will always hit the mic first?


 Arrival time doesn’t matter. If the reflected sound screws up the results, it would be because the vertical calibration file is acting to make the reflections louder than the direct sound. The mic can’t tell direct from reflected sound; the measurement will reflect whichever is the loudest - see this post for more details.

Regards, 
Wayne


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## Djnickuk (Mar 30, 2012)

Thank you wayne. Horizontal it is with 20 deg increase for mains and 20 deg decline for sides.


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## Wull (Apr 7, 2010)

Djnickuk said:


> Thank you wayne. Horizontal it is with 20 deg increase for mains and 20 deg decline for sides.


Nick, why a 20 deg decline for your sides when they are positioned 6ft in height from the floor?


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## Djnickuk (Mar 30, 2012)

Because if you think the main speaker measurement will have the mic at 20 deg incline. Then if I was to point the mic direct at the sides at around 45 deg and reduce with 20 deg decline then the mic is back within it tolerances. 

Alternitavely I could use the 45deg narrow mic file.


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## Wayne A. Pflughaupt (Apr 13, 2006)

The various calibration files assume the mic is situated more-or-less on axis with the sound source. If you have to orient the mic up 45° to get it on-axis with the speaker, that tells me the listening position is pretty close to a high-mounted speaker. If you’re that far off-axis from the speaker, you’re probably hearing less of the high frequencies. Using a 45° calibration will get measurements with exaggerated high end that’s not a good indication of what you’re actually hearing.

Regards, 
Wayne


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## Djnickuk (Mar 30, 2012)

Thanks Wayne. 

I think I experimented with using the 45deg file for the sides. As you say they are close. And I think this is why when I ran the auto eq for my Ada peq, it suggested on two different filters, for the same measurement. Ie filter 2 - 1120hz +6 db q3 then on filter 6 again 1120hz but -10db q7. I will re do these later today.

Another, perhaps very dumb question is do I need to fill in my Ada peq exactly as REW suggests, ie filter 1 @ 390hz, filter 2 @ 23, filter 3 @ 220 and so on. As I have inputed them into my Ada with the lowest frequency at the left hand of the peq and the highest on the right. 

All frequencies, gains and q are at the level REW recommended but just not on the filter numbers. Ie, I have them assigned by frequency numerically increasing from left to right.


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## Wull (Apr 7, 2010)

Good question Nick, one I have thought about myself..


My dumb question........ :bigsmile:

Going back to the 20deg. From my seated position fixed at ear height, I point the Mic toward my speaker but at a 20deg. So if I used a laser line the Mic would not be pointing at my speaker, it would more likely to be pointing some 'now I am guessing here' 3ft above as my speakers are a good 14ft from my seat.


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## Wull (Apr 7, 2010)

Djnickuk said:


> do I need to fill in my Ada peq exactly as REW suggests, ie filter 1 @ 390hz, filter 2 @ 23, filter 3 @ 220 and so on. As I have inputed them into my Ada with the lowest frequency at the left hand of the peq and the highest on the right.
> .



Looking at the REW EQ filters, it has a 'sort Ascending' box, by:

Freq
Gain
Q
BW
Area

So I guess it does not matter which order you input the results Nick.


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## Djnickuk (Mar 30, 2012)

Ah, thanks wull.

I was going to have another play today but my neighbours decded to get some earth moving machinery in. Nt great for audio calibrations.


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