# Behringer ECM8000 still the one to get??



## JimP

I've been busy the last few days getting REW 4.0 up on a Vista laptop and believe that the phantom power supply to my Behringer ECM8000 has died. Checked voltage out and its almost non existant.

I am going through a Creative external USB sound card and have verified that my Radio Shack analog SPL meter appears to respond correctly on the input signal.

Before ordering another phantom power supply, I thought I'd ask to find out if there is a better choice than the ECM8000. 

My interest is in testing more of a full frequency range than just the subwoofer range, otherwise, I'd just use the Radio Shack meter.


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## brucek

> I thought I'd ask to find out if there is a better choice than the ECM8000


No, it's quite a good mic for the money. It's also the one we have a downloadable calibration file for...

brucek


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## JimP

thanks


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## lcaillo

There are lots of similar mics that would be as good and many better than the ECM8000. It just happens to be very inexpensive. If you want something better you should consider having the ECM8000 calibrated or buying a calibrated mic. The biggest variation in measurement accuracy is likely that between mics. You can use the calibration measurements published, but that only gets you in the ballpark and you have no idea where your mic actually compares unless you have a calibrated one to compare to or you have it calibrated by a lab with NIST traceable equipment.

You will need the supply for any decent mic anyway.


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## JimP

My ECM8000 had been individually calibrated a few years ago and that was part of my concern in that if I went with another mic, I'd have to send it off to be calibrated also. I just wanted to be sure before buying another 48 volt power supply for it, there wasn't another mic that had fallen into favor.

I went all over town trying to find another 48 volt phantom power supply. Never did find one. Wound up ordering one last night from an internet company.

Which mic are you using?

Wasn't there one Sonnie was getting up a power buy for back last year??


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## Sonnie

I did a power buy for the Galaxy CM-140 SPL meter, which has a very good mic on it and it extremely consistent from meter to meter. If you didn't already have the mic, you could actually use it and not have to have the power supply.


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## brucek

> Wasn't there one Sonnie was getting up a power buy for back last year??


Yeah, that was the Galaxy CM-140 SPL meter. Quite a few people got in on that buy. We did a calibration file for it compared against sonnies ECM8000. The Galaxies were all extremely consistant in their response between each other (and sonnie tested every single one of them)............

Don't forget to test and include the response of your mic premp in the soundcard.cal file. It will increase the accuracy of your measurements (especially at the top and bottom end).

brucek


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## Sonnie

Great minds think alike... :sarcastic: (Okay, I confess, his is greater than mine by far!)


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## JimP

brucek said:


> Yeah, that was the Galaxy CM-140 SPL meter. Quite a few people got in on that buy. We did a calibration file for it compared against sonnies ECM8000. The Galaxies were all extremely consistant in their response between each other (and sonnie tested every single one of them)............
> 
> Don't forget to test and include the response of your mic premp in the soundcard.cal file. It will increase the accuracy of your measurements (especially at the top and bottom end).
> 
> brucek


I'm aware of the sound card calibration routine going into the soundcard.cal file, but not the mic preamp. Are you talking about the levels thing?


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## Sonnie

Just connect your mic preamp in the loop with making your soundcard.cal file. This will account for any frequency response deficiencies your mic preamp may have. I can't remember how much it was, but my mic preamp was off a little bit down low and it may have been off a little up high as well.


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## JimP

Physically, on the preamp, connect a wire to the "mic input" and the other end to the line out (I think its marked "speaker") of the sound card?


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## Sonnie

I believe it would be:

Line Out (Sound Card) >> Line In (Mic Preamp) 

Line Out (Mic Preamp) >> Line In (Sound Card)

Make sure your preamp controls are set properly... bass and treble set to neutral.


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## brucek

> I'm aware of the sound card calibration routine going into the soundcard.cal file, but not the mic preamp. Are you talking about the levels thing?


When you run the soundcard calibration routine (once only) you connect a cable from the line-out to the line-in and create a file that will be used to compensate for any response anomalies of the soundcard. This soundcard.cal file applies the inverse of the soundcards response to make the soundcard appear perfect. 

In this case, when we run this routine, we simply include the ECM8000 preamp into the cable that loops from the soundcard line-out to line-in. It's response is added into the soundcards response to be inversely applied.

Below is the response of my UB802 preamp. You can see why it would be nice to eliminate it's inadequacies. It's good, but it ain't perfect. It drops off at the upper and lower end a little bit and the 'detent' position of the eq of the mixer pots isn't perfect.

This response is added into the soundcard.cal file, and so when we measure, the preamp becomes 'perfect', and doesn't add anything to the measurement.










brucek


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## JimP

brucek,

Thanks for the explaination.

Back when I sent my mic off for the calibration file, I also sent the preamp. I'm wondering how likely it is that they included the preamp in the measurement. I did order an identical preamp.

Think I'll compare the mic calibration file to the one on the download page (or where ever it is) to see how they compare.


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## JimP

Here's from the download page

5.00 -24.79
6.30 -16.22
8.00 -12.54
10.00 -9.23
12.50 -6.64
16.00 -4.68
19.95 -3.09
25.12 -2.08
31.62 -1.30
39.81 -0.83
50.12 -0.41
63.10 -0.14
79.43 0.00
100.00 0.15
125.89 0.22
158.49 0.22
199.53 0.26
251.19 0.26
316.23 0.26
398.11 0.22
501.19 0.20
630.96 0.14
794.33 0.07
1000.00	0.00
1258.93	-0.07
1584.89	-0.13
1995.26	-0.23
2511.89	-0.27
3162.28	-0.13
3981.07	-0.22
5011.87	-0.30
6309.57	-0.25
7943.28	-0.17
10000.00 -0.15
12589.25 -3.77
15848.93 -7.48
19952.6 -9.01


....and here's the file generated from my mic

10.000 -1.729 22.055
10.286 -1.582 22.120
10.580 -1.441 22.128
10.883 -1.305 22.025
11.194 -1.174 21.853
11.515 -1.052 21.687
11.844 -0.941 21.527
12.183 -0.835 21.360
12.531 -0.724 21.203
12.890 -0.608 21.065
13.259 -0.491 20.910
13.638 -0.373 20.691
14.028 -0.253 20.404
14.429 -0.136 20.080
14.842 -0.021 19.713
15.267 0.090 19.294
15.704 0.196 18.808
16.153 0.294 18.269
16.615 0.382 17.696
17.090 0.459 17.096
17.579 0.519 16.503
18.082 0.571 15.929
18.599 0.618 15.420
19.132 0.660 14.942
19.679 0.699 14.469
20.242 0.735 14.031
20.821 0.770 13.631
21.417 0.803 13.245
22.029 0.837 12.883
22.660 0.872 12.558
23.308 0.910 12.240
23.975 0.953 11.923
24.660 1.001 11.602
25.366 1.052 11.230
26.092 1.104 10.814
26.838 1.153 10.353
27.606 1.197 9.831
28.396 1.232  9.272
29.208 1.251 8.706
30.044 1.263 8.193
30.903 1.272 7.720
31.787 1.281 7.263
32.696 1.288 6.822
33.632 1.293 6.379
34.594 1.296 5.949
35.584 1.296 5.510
36.602 1.291 5.084
37.649 1.281 4.676
38.726 1.268 4.298
39.834 1.254 3.955
40.973 1.240 3.630
42.146 1.227 3.322
43.351 1.212 3.020
44.591 1.196 2.738
45.867 1.179 2.479
47.179 1.164 2.231
48.529 1.149 1.991
49.917 1.133 1.766
51.345 1.118 1.548
52.814 1.103 1.335
54.325 1.088 1.132
55.879 1.072 0.939
57.478 1.057 0.753
59.122 1.042 0.573
60.814 1.026 0.399
62.554 1.011 0.231
64.343 0.996 0.069
66.184 0.981 -0.087
68.077 0.965 -0.237
70.025 0.950 -0.382
72.028 0.935 -0.521
74.089 0.920 -0.655
76.208 0.904 -0.785
78.388 0.889 -0.910
80.631 0.874 -1.032
82.938 0.859 -1.150
85.310 0.843 -1.262
87.751 0.828 -1.369
90.261 0.813 -1.475
92.844 0.797 -1.576
95.500 0.782 -1.672
98.232 0.767 -1.767
101.040 0.752 -1.855
103.930 0.736 -1.943
106.910 0.721 -2.024
109.960 0.706 -2.105
113.110 0.691 -2.180
116.350 0.675 -2.252
119.670 0.660 -2.322
123.100 0.645 -2.389
126.620 0.630 -2.451
130.240 0.614 -2.510
133.970 0.599 -2.566
137.800 0.584 -2.619
141.740 0.569 -2.669
145.800 0.553 -2.718
149.970 0.540 -2.776
154.260 0.509 -2.911
158.670 0.468 -2.655
163.210 0.499 -2.565
167.880 0.489 -2.675
172.680 0.490 -2.605
177.620 0.508 -2.639
182.710 0.523 -2.895
187.930 0.508 -3.174
193.310 0.467 -3.308
198.840 0.452 -3.419
204.530 0.399 -3.588
210.380 0.344 -3.432
216.400 0.331 -3.205
222.590 0.335 -3.109
228.960 0.324 -3.089
235.510 0.311 -2.872
242.240 0.343 -2.880
249.170 0.345 -2.921
256.300 0.359 -2.880
263.630 0.388 -3.099
271.180 0.369 -3.289
278.940 0.363 -3.478
286.910 0.320 -3.619
295.120 0.307 -3.634
303.570 0.281 -3.695
312.250 0.246 -3.644
321.180 0.246 -3.450
330.370 0.242 -3.476
339.820 0.236 -3.375
349.550 0.256 -3.411
359.550 0.243 -3.453
369.830 0.256 -3.431
380.410 0.256 -3.529
391.290 0.263 -3.561
402.490 0.279 -3.750
414.000 0.243 -3.943
425.850 0.243 -3.927
438.030 0.239 -4.111
450.560 0.216 -4.186
463.450 0.186 -4.156
476.710 0.194 -4.150
490.350 0.192 -4.166
504.380 0.180 -4.315
518.800 0.181 -4.212
533.650 0.180 -4.326
548.910 0.174 -4.377
564.620 0.178 -4.365
580.770 0.193 -4.588
597.380 0.172 -4.736
614.470 0.168 -4.798
632.050 0.159 -4.880
650.140 0.153 -4.962
668.730 0.154 -5.079
687.870 0.145 -5.235
707.540 0.138 -5.346
727.790 0.126 -5.433
748.610 0.122 -5.549
770.020 0.113 -5.705
792.050 0.101 -5.792
814.710 0.099 -5.934
838.020 0.081 -6.098
861.990 0.067 -6.190
886.650 0.056 -6.313
912.020 0.045 -6.442
938.110 0.031 -6.570
964.950 0.017 -6.686
992.550 0.005 -6.826
1020.900 -0.014 -6.946
1050.200 -0.027 -7.074
1080.200 -0.042 -7.194
1111.100 -0.061 -7.336
1142.900 -0.078 -7.477
1175.600 -0.100 -7.585
1209.200 -0.124 -7.723
1243.800 -0.148 -7.824
1279.400 -0.178 -7.920
1316.000 -0.209 -7.958
1353.600 -0.236 -7.963
1392.400 -0.267 -7.951
1432.200 -0.292 -7.888
1473.200 -0.312 -7.813
1515.300 -0.325 -7.650
1558.700 -0.333 -7.507
1603.300 -0.333 -7.346
1649.100 -0.320 -7.212
1696.300 -0.307 -7.062
1744.800 -0.290 -6.877
1794.800 -0.251 -6.689
1846.100 -0.207 -6.529
1898.900 -0.146 -6.432
1953.200 -0.072 -6.356
2009.100 0.016 -6.400
2066.600 0.108 -6.587
2125.700 0.205 -6.892
2186.500 0.305 -7.310
2249.100 0.393 -7.918
2313.400 0.459 -8.584
2379.600 0.521 -9.323
2447.700 0.559 -10.094
2517.700 0.586 -10.840
2589.700 0.604 -11.559
2663.800 0.619 -12.256
2740.000 0.635 -12.961
2818.400 0.651 -13.669
2899.000 0.665 -14.460
2982.000 0.670 -15.307
3067.300 0.658 -16.202
3155.000 0.625 -17.080
3245.300 0.571 -17.843
3338.100 0.509 -18.452
3433.600 0.451 -18.882
3531.900 0.413 -19.177
3632.900 0.403 -19.396
3736.800 0.432 -19.720
3843.800 0.470 -20.247
3953.700 0.507 -21.004
4066.800 0.511 -21.903
4183.200 0.476 -22.762
4302.800 0.420 -23.394
4425.900 0.378 -23.720
4552.600 0.372 -23.985
4682.800 0.400 -24.316
4816.800 0.436 -24.776
4954.600 0.462 -25.208
5096.300 0.512 -25.467
5242.100 0.624 -25.693
5392.100 0.803 -26.352
5546.300 0.979 -27.715
5705.000 1.091 -29.558
5868.200 1.100 -31.351
6036.100 1.090 -32.673
6208.800 1.119 -33.829
6386.400 1.175 -35.251
6569.100 1.201 -36.827
6757.000 1.199 -38.343
6950.300 1.190 -39.720
7149.200 1.204 -41.054
7353.700 1.238 -42.503
7564.100 1.260 -44.119
7780.500 1.257 -45.638
8003.100 1.274 -46.930
8232.000 1.368 -48.296
8467.500 1.488 -50.338
8709.800 1.534 -52.852
8958.900 1.501 -55.163
9215.200 1.485 -57.108
9478.900 1.517 -59.195
9750.000 1.537 -61.711
10029.000 1.493 -64.254
10316.000 1.449 -66.549
10611.000 1.415 -68.947
10915.000 1.353 -71.309
11227.000 1.346 -73.347
11548.000 1.415 -76.114
11878.000 1.362 -79.515
12218.000 1.234 -82.242
12568.000 1.200 -84.762
12927.000 1.177 -87.942
13297.000 1.071 -91.135
13677.000 1.018 -94.015
14069.000 0.954 -97.796
14471.000 0.757 -101.086
14885.000 0.673 -104.005
15311.000 0.596 -107.519
15749.000 0.499 -111.177
16200.000 0.375 -114.971
16663.000 0.271 -118.824
17140.000 0.144 -123.113
17630.000 -0.011 -127.337
18135.000 -0.135 -132.047
18653.000 -0.352 -137.174
19187.000 -0.609 -142.305
19736.000 -0.904 -147.589
20301.000 -1.285 -153.027


Any thoughts??


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## brucek

> Back when I sent my mic off for the calibration file, I also sent the preamp. I'm wondering how likely it is that they included the preamp in the measurement.


I just can't imagine that any professional calibration would include the preamp.

Here's the comparison of your calibration versus Sonnie's. 

I don't know what to think of your calibration - it doesn't drop off as I would think it should and it sure jumps around at higher frequencies. Doesn't seem correct.

Maybe others can comment....










brucek


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## lcaillo

Who did the calibration, JimP?

These are the numbers for my ECM8000, similar to Sonnies numbers, calibrated by the same lab.

19.95 -3.14
25.12 -1.78
31.62 -0.78
39.81 -0.16
50.12 0.31
63.10 0.54
79.43 0.71
100.00 0.77
125.89 0.78
158.49 0.72
199.53 0.64
251.19 0.53
316.23 0.40
398.11 0.34
501.19 0.20
630.96 0.14
794.33 0.10
1000.00 0.00
1258.93 0.08
1584.89 0.15
1995.26 0.20
2511.89 0.28
3162.28 0.39
3981.07 0.67
5011.87 0.74
6309.57 0.98
7943.28 2.09
10000.00 1.11
12589.25 -0.78
15848.93 -3.31


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## JimP

The mic was calibrated by Wadenhome Sound out of Winona, MN.

On the diskette, it does show it being the ECM8K.

Once I get the replacement phantom power supply, I think I'll run a test using my Radio Shack SPL meter with the correction file for it and compare it to the Behringer mic with each of the two Behringer correction files. With any luck, the Radio Shack sweep with match one of the two Behringer sweeps.
Lets hope all three aren't different. :rolleyesno:


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## lcaillo

I would not give that kind of calibration much credibility. Here is the response that I got from him when I asked what kind of equipment he used:

"The ref mic was calibrated when I purchased it by the manufacturer -- ACO 
Pacific. Mics of this type are typically stable to about 1 dB per 250 years 
(or something like that). http://www.acopacific.com/micdetal.html
I've had the mic about 10 years. The original capsule was damaged and 
replaced about 5 years ago."

This is what prompted me to use West Caldwell Labs, the one that Sonnie eventually used for his as well. They are NIST traceable, which means that their equipment is calibrated regularly and validated. Using a ten year old calibration file from a manufacturer and having changed the capsule is not a reliable reference for calibration. I wonder how Sonnie's calibration files compared between Kim's numbers and those from WCCL. Did he send them the same mic?

Just get a power supply and have the mic calibrated again if you want to know what you are actually measuring.


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## JimP

Agreed, time for a second calibration. 

Speaking of which, I wonder how often we should get these microphones recalibrated. Anyone know?


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## Sonnie

There was quite a difference between Kim's calibration and WCCL. I suggest WCCL is definitely the real deal and can be trusted.

I have a second ECM8000 and it traces fairly close to my other one. With Leonard's tracking fairly close and being calibrated at WCCL... I'd suggest that the WCCL cal file would be more accurate. 

As Leonard suggest though, about the only way to be absolute certain is send it off.

You are more than welcome to use mine if you would like Jim. I've got to come your way sometime soon to pick up a part at the Hyundai dealership for Angie's Azera. I could swing by your place and drop it off. Of course you will probably want to have yours calibrated so you can have it readily available at any time. I would use WCCL.


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## JimP

Sonnie,

I'd appreciate the loan of the calibrated mic. Gives me another reference point. 

Let me know when would be a good time for you. 

As an option, I can pick up the part from Hyundai and bring it out there to you.


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## Sonnie

No problem. I've been procrastinating coming your way for a few weeks now. It should be fairly soon though. If not soon enough I can always drop it in the mail to you. I don't think it will happen this week because we are suppose to be moving our office. I'm just gonna have to make time.


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## clubfoot

Just wanted to add that you can purchase an ECM8000 mic and M-Audio Audio Buddy pre amp with 48v phantom power for US$49.99 each from Guitar Center. I will post my cal file once I get it back from WCCL.


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## brucek

> I will post my cal file once I get it back from WCCL.


We would appreciate that. The more professional files we have, the more confidence that the ECM8000 is fairly consistent between units...

brucek


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## JimP

The replacement 48 volt phantom power supply arrived today.

No joy. Either I got a dud or I'm doing something wrong.

When using the Radio Shack spl meter, the input level is about where it needs to be without much adjustments. When using the Behringer mic through the phantom power supply, it measures too low which is why I though I had a bad phantom power supply and ordered the replacement. 

The new phantom power supply(PPS) is the same brand and model as the one I've had. I can not say conclusively that the first one was working properly as I recall getting low input levels with it when I tried REW a couple of years back on a different computer.

I tried to take voltage measurement off of the PPS to compare with the Radio Shack Meter. What I found with the PPS is that the voltage on the mic side stays constant where the voltage on the output side starts off high and tapers off to nothing within moments of plugging them into the a/c outlet. 

By the way, the phantom power supply is the audio technica AT8801.

Has anyone encountered anything like this?


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## brucek

> What I found with the PPS is that the voltage on the mic side stays constant where the voltage on the output side starts off high and tapers off to nothing within moments of plugging them into the a/c outlet.


Could you elaborate on this? Are you talking about the +48 volt DC?

brucek


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## JimP

On the microphone side of the phantom power supply, the voltage between pins 2(+) and 1or3(ground) measures around 42 to 44 volts dc on both AT8801s.

On the output side of the phantom power supply going to the external sound card, the voltage spikes and then drops off to zero. I've tried it with and without the microphone connected.

One of the features of this PPS is that it has a circuit protection feature where it shuts itself off under certain conditions. My guess is that there is a basic incompatability problem with the Behringer mic.

I also tested the voltage out on the xlr microphone plug on my SMS-1(Velodyne equalizer). It only showed 12 volts which makes me think that the mic is getting too much power. Hope I didn't damage the mic.

This morning I'm going to head off to Guitar Center to see if they've got the Behringer 802. I'd rather stop spinning my wheels with what evidently isn't working and go with something that has worked for (wasn't it you?)one of the other members.


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## brucek

> On the output side of the phantom power supply going to the external sound card, the voltage spikes and then drops off to zero. I've tried it with and without the microphone connected.


But the AT8801 is simply a phantom power supply. It's not a pre-amp. The output voltage should be zero DC as you have measured, since it would be capacitively coupled. The signal is now a low level AC signal. You can't fed a line level soundcard directly. You must amplify the low level signal with a preamp.

The 802 is a phantom power supply and preamp in one box and works quite nice with the ECM8000...

brucek


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## JimP

Just got back from Guitar Center with the 802.

brucek, The way you explain it, it now makes sense. Thanks. I know I've seen quite a few post about using the Behringer mic with the phantom power supply for audio analysis without mention of a preamp. Live and learn.


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## brucek

Here's a pic of where I have my pots set on the 802. It may help you get going...

Be sure the EQ dials are in their detent positions..









brucek


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## JimP

Thanks for the jpg. I thought I had seen that somewhere but couldn't remember where.
Should the "CD/Tape To CTRL" and "CD/Tape to Mix" buttons be in the out position and "phantom power" in the in position ?


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## brucek

> Should the "CD/Tape To CTRL" and "CD/Tape to Mix" buttons be in the out position and "phantom power" in the in position ?


Yep, but wait until you plug in the mic before turning on the phantom +48 volts.....

brucek


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## Bob_99

Very timely thread as it covers something that I was wondering about myself. 

Bob


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## clubfoot

brucek said:


> We would appreciate that. The more professional files we have, the more confidence that the ECM8000 is fairly consistent between units...
> 
> brucek


I sent it off for calibration today, should be back in a week.


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## JimP

clubfoot,

About how much does a mic calibration cost?


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## Sonnie

I believe mine with WCCL was $118.75. Initially they told me $150, but it ended up being less.


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## JimP

brucek said:


> I just can't imagine that any professional calibration would include the preamp.
> 
> Here's the comparison of your calibration versus Sonnie's.
> 
> I don't know what to think of your calibration - it doesn't drop off as I would think it should and it sure jumps around at higher frequencies. Doesn't seem correct.
> 
> Maybe others can comment....
> 
> 
> View attachment 3655
> 
> 
> brucek


I've been thinking about your post for a few days. 
I have to say that neither curve resembles what you would expect as a correction from Behringer's website. http://www.behringerdownload.de/ECM8000/ECM8000_C_Specs.pdf

As other's get their mic's calibrated, it might be of some value to post them along side Sonnie's for comparison purposes.


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## clubfoot

JimP said:


> clubfoot,
> 
> About how much does a mic calibration cost?


I was quoted CN$121.00 from the US lab. I dropped it of at the Canadian lab today but they will be sending it off to the US, because their equipment is getting its annual recalibration. And I will be posting it up here once I get it back from calibration. They also offered to calibrate my pre amp as well, but I can compensate for it in a soundcard and pre amp loop .cal file.


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## brucek

Note the difference in the vertical scales. The graph you reference of Sonnies ECM8000 goes to -10dB, while Behringers goes to -30dB.

Also note they only extend theirs down to 60Hz. The only real difference is up high. Sonnies drops of at 10Khz and theirs drops at 20Khz. 

Every ecm we've tested has been close to sonnies. They're quite consistent.

Here's sonnies in a comparison using the scale that behringer used (-30dB to +20dB for vertical)................. different, but closer visually anyway. behringer chose a scale that made the results look better than they are....


















brucek


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## lcaillo

Manufacturers have the ability to average over many measurements. The resulting curves may look much smoother as a result and a given mic may vary considerably from that average. This is the reason for calibration. It is the same reason that two displays can look very different when using exactly the same values for the various calibration parameters.


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## BoomieMCT

brucek said:


> I just can't imagine that any professional calibration would include the preamp.
> 
> Here's the comparison of your calibration versus Sonnie's.
> 
> I don't know what to think of your calibration - it doesn't drop off as I would think it should and it sure jumps around at higher frequencies. Doesn't seem correct.
> 
> Maybe others can comment....
> 
> 
> View attachment 3655
> 
> 
> brucek



My ECM8000 seems to drop off at 10kHz (kind of like the picture of Sonnie's above). Is there a .cal file for RoomEQ with that contour?


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## brucek

> Is there a .cal file


All the files are on the downloads page. The ECM8000 is there....

brucek


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## BoomieMCT

brucek said:


> All the files are on the downloads page. The ECM8000 is there....
> 
> brucek


Thanks! For some reason I could not find it last night.


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## clubfoot

brucek said:


> We would appreciate that. The more professional files we have, the more confidence that the ECM8000 is fairly consistent between units...
> 
> brucek


brucek, picked up my ecm8000 today, .cal file attached. Not sure why they did not calibrate to 5Hz and to 20KHz, like sonnie's file?


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## brucek

> .cal file attached. Not sure why they did not calibrate to 5Hz and to 20KHz


Thanks for posting that. It confirms once again that the calibration between different units is quite close. Amazingly close actually.

Sonnie asked for and paid to have his measurement extended, since a lot of IB users here wanted it down to 5Hz - crazy as that might be.. 

The good news is you can see how close the two files are down below the 20Hz and you can safely add those values to your file by simply changing the extension to a .txt file and edit it with notepad and save. Then change the extension back to .cal - easy.

It does start to deviate slightly at 10Khz. At 10KHz it's 0.89dB different.











brucek


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## clubfoot

brucek said:


> The good news is you can see how close the two files are down below the 20Hz and you can safely add those values to your file by simply changing the extension to a .txt file and edit it with notepad and save. Then change the extension back to .cal - easy.
> 
> It does start to deviate slightly at 10Khz. At 10KHz it's 0.89dB different.
> 
> brucek


Thanks I'll do that


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## aktiondan

Are there a lot of people who have their ECM8000's calibrated? I wonder if there would be some benefit to loading up into Excel all the cal curves of everyone whose had theirs cal'd and doing an average of them all to create one single normalized cal file. You figure any data that includes a sample size greater than one has to be more accurate. Though the low-frequency variation appears to be negligible, it's the high-frequency component that I'd be more interested in getting some better accuracy out of.


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## brucek

We've examined quite a few and came to the conclusion that they're quite close, especially in the region used for subwoofer equalization. Sonnie's file is available free on the download site. Many people use it for their ECM mics. If you require accuracy in the above 10KHz region (where the discrepency appears to be), I think it would be best to have your mic calibrated.

brucek


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## JimP

dan

Let me put it to you like this.

This is how you feel when you think you've saved a few dollars by using someone else's calibration file. :jump:


This is how you feel 3 years later when you've spent a pile of money and a ton of time correcting a problem in your accoustics that wasn't really there because the calibration file compounded a deficit in the mic. :hissyfit:

Anything else you'd like to know? :bigsmile:


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## brucek

> Anything else you'd like to know?


I think I'll include a link to the situation you are referring to here, so we can get context, would be best....

brucek


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## aktiondan

JimP, that sounds terrible, sorry to hear about that. In that case, I think I will get my mic calibrated. So is Kim still doing calibrations? I noticed that a few people mentioned him, but wasn't sure if he was still doing them. If he still does, then I would love to send him my new ECM8000 for cal. I like that he does the full-range (out to 46kHz) with 300 data points resolution, where it appears as though WCCL uses a limited bandwidth and lower resolution cal. Is still the case?


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## JimP

Even though my mic was properly calibrated by Kim, recent discussions with Kim by a couple of forum members have raised questions about the accuracy of his current calibrations.

If I were you, I'd use WCCL and request the broader frequency range.


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