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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Audio Measurement and Testing => Topic started by: Carl Fischer on December 11, 2019, 04:51:36 PM

Title: ECFs'. To use or not to use, that is my question.
Post by: Carl Fischer on December 11, 2019, 04:51:36 PM

I'm sure this has been discussed before, but I'll ask for some opinions again regardless.

I'll shortly be testing this soon with my earthworks M23. Capturing a response with and without the ECF inserted.

I recently setup a Sound System for Howard Page and while I had him close to me I asked him as many questions as I could.

One question I asked was if he used a calibration file for his RTA mic and he said "no, never."

So I ask:

1) What is a calibration file?

2) If you have a relatively flat response on you RTA mic, does the file matter?

Title: Re: ECFs'. To use or not to use, that is my question.
Post by: Nathan Riddle on December 12, 2019, 11:57:15 AM

Quote from: Carl Fischer on December 11, 2019, 04:51:36 PM

I'm sure this has been discussed before, but I'll ask for some opinions again regardless.

I'll shortly be testing this soon with my earthworks M23. Capturing a response with and without the ECF inserted.

I recently setup a Sound System for Howard Page and while I had him close to me I asked him as many questions as I could.

One question I asked was if he used a calibration file for his RTA mic and he said "no, never."

So I ask:

1) What is a calibration file?

2) If you have a relatively flat response on you RTA mic, does the file matter?

1) it looks like the below. Its a factory created file so the mic reads 'true' compared to 1kHz

Quote

;www.isemcon.com      freefield
;sensitivity   7.05   mV/Pa @ 1kHz
10   -1.25   
11.2   -0.89   
12.5   -0.76   
14   -0.57   
16   -0.41   
18   -0.3   
20   -0.19   
22.4   -0.11   
25   -0.05   
28   0   
31.5   0.06   
35.5   0.09   
40   0.12   
45   0.15   
50   0.17   
56   0.18   
63   0.19   
71   0.2   
80   0.21   
90   0.21   
100   0.21   
112   0.21   
125   0.21   
140   0.21   
160   0.21   
180   0.2   
200   0.2   
224   0.19   
250   0.18   
280   0.18   
315   0.17   
355   0.16   
400   0.15   
450   0.13   
500   0.12   
560   0.11   
630   0.09   
710   0.07   
800   0.05   
900   0.03   
1000   0   
1120   -0.02   
1250   -0.09   
1400   -0.07   
1600   -0.13   
1800   -0.15   
2000   -0.17   
2240   -0.18   
2500   -0.23   
2800   -0.28   
3150   -0.28   
3550   -0.23   
4000   -0.3   
4500   -0.5   
5000   -0.53   
5600   -0.35   
6300   -0.3   
7100   -0.13   
8000   -0.12   
9000   -0.01   
10000   0.09   
11200   0.32   
12500   0.59   
14000   0.59   
16000   0.27   
18000   -0.06   
20000   -0.24

2)
No, definitely not RTA, DualFFT sure.

Note the most difference is @ 10Hz ~1dB. Not enough to be a big deal IMO.

---

I use a calibration file because it's easy to put in SMAART and keep there and use when I'm using my EMX-7150 mic.

I don't bother with a calibration file the ECM8000 Behringer mics as those are mostly used for general tunings & main/sub alignments.
occasionally I'll compare to my EMX-7150 and they are within 3dB and that's okay for field measurements IMO.