Behringer ECM8000 still the one to get??

**JimP** · **06-17-07, 05:40 PM**

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.

**brucek** · **06-17-07, 05:52 PM**

Quote:

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

**JimP** · **06-17-07, 06:13 PM**

thanks

**lcaillo** · **06-18-07, 07:56 AM**

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.

**JimP** · **06-18-07, 10:14 AM**

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??

**Sonnie** · **06-18-07, 10:55 AM**

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.

**brucek** · **06-18-07, 10:55 AM**

Quote:

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

**Sonnie** · **06-18-07, 10:56 AM**

Great minds think alike...

(Okay, I confess, his is greater than mine by far!)

**JimP** · **06-18-07, 01:56 PM**

Quote:

brucek wrote:

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?

**Sonnie** · **06-18-07, 02:07 PM**

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.

**JimP** · **06-18-07, 02:26 PM**

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?

**Sonnie** · **06-18-07, 03:11 PM**

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.

**brucek** · **06-18-07, 05:14 PM**

Quote:

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.

ub802loop_response_res.jpg

brucek

**JimP** · **06-18-07, 06:01 PM**

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.

**JimP** · **06-18-07, 06:14 PM**

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??

**brucek** · **06-18-07, 08:19 PM**

Quote:

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....

compare.jpg

brucek

**lcaillo** · **06-18-07, 08:57 PM**

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

**JimP** · **06-18-07, 09:13 PM**

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.

**lcaillo** · **06-18-07, 09:30 PM**

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.

**JimP** · **06-18-07, 10:29 PM**

Agreed, time for a second calibration.

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

**Sonnie** · **06-18-07, 10:32 PM**

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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