How to place a measurement microphone

[Golitan11]

Also how do you set the level on a subwoofer for calibration? (do you need to use it for calibration?)

[Golitan11]

Ok for the microphone position it's ok but I am still wondering how to take measurements with a subwoofer. Thanks!

[Lights]

I can't tell you definitively, but I have the same mic, and I tried it pointing directly to the speaker when testing a single channel, pointing it to the midpoint between the two when testing stereo, and pointing it directly to the ceiling, and for the most part the measurements were equivalent. I saw posts saying both options and found either seemed to work.

[DanDan]

Depends what you want to measure. For modes it is best to place the mic and speaker in opposing floor/ceiling corners. Maximum input, maximum reception.
If you want to balance surround speakers you would point the mic equally away from all speakers, up or down, whichever looks deader.
If you want to estimate what you will actually hear, then place the mic where each ear is and point it at it's corresponding speaker.
Take measurements driving one speaker only, unless you have a really coherent reason to do otherwise.

http://www.gearslutz.com/board/studi...er-v2-1-a.html

Be aware these affordable mics are not very good quality. They are not flat and not omnidirectional. Turn on smoothing when viewing over 300Hz, and don't take it too seriously.

DD

[Golitan11]

Ok thanks DD! What about the subwoofer? Thanks.

[Golitan11]

Also can you use a measurement microphone as a SPL meter?

[Golitan11]

I will make a list of questions instead LOL:

1. How do I set my subwoofer level correctly?
2. Can you use the ECM8000 as a SPL meter?
3. When I set my input level to max on my Komplete Audio 6 the level only go up to -40dB (during REW 5 calibration process). What do I do to match the -10dB Output? Do I crank the output level up?

Thanks!

[Glenn Kuras]

See if the following video answers some of your questions. Testing is great but don't get to anal about it. What you are looking for is an improvement from one test to another as you treat or set up your mix spot.
REW Room EQ Wizard Room Measurement Tutorial video

[Jens Eklund]

Originally Posted by Golitan11

I bought a Behringer ECM8000 a few hours ago and I was just wondering how to place the microphone for room measurement. Should it face the floor, the ceiling, the speakers, etc. ? Thanks!

Why point the mic at the ceiling?

[boggy]

Originally Posted by Golitan11

"Also how do you set the level on a subwoofer for calibration?
(do you need to use it for calibration?)"

No.

Originally Posted by Golitan11

I will make a list of questions instead LOL:

1. How do I set my subwoofer level correctly?

Normal listening level is enough (not quiet!), without needs for earplugs, and without clipping...

Originally Posted by Golitan11

2. Can you use the ECM8000 as a SPL meter?

No. You need to calibrate microphone senistivity (at least) somewhere, for SPL measuring. So answer is no.

Originally Posted by Golitan11

3. When I set my input level to max on my Komplete Audio 6 the level only go up to -40dB (during REW 5 calibration process). What do I do to match the -10dB Output? Do I crank the output level up?

This is possibly line-level-to-line-level-loopback "calibration"... I rarely use REW, and I never "calibrate" anything there, because virtually all acoustic measurements used here, don't need any calibration...
Also I'm pretty sure that user manual describe calibration process, if it is needed at all...
I use ARTA, and I calibrate there output level of my audio card, at 100Hz, I measure balanced output level with multimeter... and I put this value in ARTA utility for calibration... after that... ARTA define loop gain and compensate channel gain differences, I need this only for measuring gain of some, non acoustical, DUT (Device Under Test), or, with info about microphone sensitivity, for SPL measuring/acquisition... all of this procedures, are pretty irrelevant for measuring room interference distribution.... so you don't need it. If you have external independent output level control, set your card output to -1dBFS (or first maximum undistorted level)... sound pressure level adjust as I expleain above, and go!

[Golitan11]

Thanks boggy! That's what I was waiting for.