Cross-Spectrum Microphone Calibration Service - USA

**Anechoic** · **06-16-09, 12:37 AM**

Just as an FYI, it took me a while but I finally have inventory again for the "full" calibrated units so I'm back to same-day shipping for orders placed before 1pm eastern time. I have a limited number of the "basic" calibration so I imagine those will get backordered pretty quickly.

Please note that "special orders" (extended freq response, multiple angles, etc) will still take 4-5 business days to ship.

Also, summer tends to be a busy time for my noise control-consulting business. If you want to send me a mic to cal but you need it back quickly, please contact me, before you mail it so I can see if I can fit it into my schedule. If you just send it, it may be a week or so before I can get it back to you.

**cavchameleon** · **06-16-09, 11:22 AM**

This is very useful info Anechoic! Thanks for all the info and link to the acoustic calibrator.

I'm looking for a link to your site (for purchase of a calibrated mic) but cannot seem to find it in your alias pop-up.

**Anechoic** · **06-16-09, 11:52 AM**

Quote:

cavchameleon wrote:

I'm looking for a link to your site (for purchase of a calibrated mic) but cannot seem to find it in your alias pop-up.

Here you go.

**cavchameleon** · **06-16-09, 11:55 AM**

Quote:

Anechoic wrote:

Here you go.

Thanks, I appreciate it! Is there a way to put in in a link to your alias for future inquires (would make it very easy).

**Anechoic** · **06-16-09, 11:59 AM**

I added it to my profile so when you click on "Visit Anechoic's homepage!" under "Anechoic" it goes to that page. Is that what you meant?

**cavchameleon** · **06-16-09, 12:04 PM**

Quote:

Anechoic wrote:

I added it to my profile so when you click on "Visit Anechoic's homepage!" under "Anechoic" it goes to that page. Is that what you meant?

Yep!

Thanks a lot, this was what I was looking for in the first place and could not find a link.

Thanks!
Ray

**Tchao** · **06-18-09, 07:59 AM**

Quote:

Anechoic wrote:

Sorry Tchao, I didn't see this post.

No problem !

I don't know - if the microphone has conventional power and signal connections, then yes, but if it uses some propriety Pioneer connection, then no.
it's a microphone with a jack connexion and no power, only the jack connexion. I tried it with REW, it works well, but without a calibration file it's not really usefull ...

thank you for the answers, I will contact you by email as "Tchao", just to have the link of this conversation.

Bye

**cavchameleon** · **06-19-09, 12:18 PM**

Anechoic,

Hi! Just placed an order for a full spectrum ECM8000. Just a question, I also have a dbx RTA-M mic. Is it worth getting this one calibrated (would it be more accurate than the ECM8000)? Just wondering if the capsule in the dbx is better than the Behringer version.

Thanks,
Ray

**Anechoic** · **06-19-09, 12:30 PM**

Quote:

cavchameleon wrote:

Anechoic,

Hi! Just placed an order for a full spectrum ECM8000. Just a question, I also have a dbx RTA-M mic. Is it worth getting this one calibrated (would it be more accurate than the ECM8000)? Just wondering if the capsule in the dbx is better than the Behringer version.

Thanks,
Ray

Just got your order and I'll be shipping it shortly.

As for the RTA-M, I've measured a few of them (in fact I own one that came with my Sencore RTA) and they're more consistent from unit-to-unit but they still have the upper frequency diffraction bump that most mics have, although it's higher in frequency than the ECM800's because of the smaller diameter of the ECM8k.

I haven't taken one apart, but I would be surprised if the RTA-M and the ECM8000 used different mic capsules (or at least unrelated capsules). I suspect that dbx's OEM is more careful in assembling the units which accounts for their better consistency. But that's speculation on my part.

**cavchameleon** · **06-19-09, 12:42 PM**

Quote:

Anechoic wrote:

Just got your order and I'll be shipping it shortly.

As for the RTA-M, I've measured a few of them (in fact I own one that came with my Sencore RTA) and they're more consistent from unit-to-unit but they still have the upper frequency diffraction bump that most mics have, although it's higher in frequency than the ECM800's because of the smaller diameter of the ECM8k.

I haven't taken one apart, but I would be surprised if the RTA-M and the ECM8000 used different mic capsules (or at least unrelated capsules). I suspect that dbx's OEM is more careful in assembling the units which accounts for their better consistency. But that's speculation on my part.

Thanks Anechoic!!! I'll let you know when I receive the mic. As far as the RTA-M, is the price of calibration the same as the ECM8000? I think it would still be nice to have it calibrated if I plan to use it at all. If you need to PM me the info (not sure if price/etc allowed in thread forums), that would be fine.

Ray

**cavchameleon** · **06-23-09, 01:52 PM**

Anechoic,

Received my calibrated ECM8000 today. Thanks a lot for such quick service!!!

Ray

**Sonic Icons** · **07-01-09, 12:45 AM**

Hi,

First, I would like to thank you (Anechoic) for helping this forum with your calibration services and technical insights. I have a question about the "generic" Behringer ECM-8000 calibration file on the Downloads page, with filename "ECM8000-CS.cal". Is this file based on an average of measurements of ECM-8000's done in your lab? To me, the "generic" calibration file looks flatter in the bass than I would have guessed from the range of response curves you showed in message #43. The "generic" file has -1.40 dB at 20 Hz, -0.54 dB at 25 Hz, while the curves in message #43 appear to range from -5.5 dB to +1 dB at 20 Hz, and from -4 dB to +1 dB at 25 Hz.

**brucek** · **07-01-09, 10:09 AM**

Quote:

I have a question about the "generic" Behringer ECM-8000 calibration file on the Downloads page, with filename "ECM8000-CS.cal". Is this file based on an average of measurements of ECM-8000's done in your lab?

No, Cross Spectrum does not load the files on our download page.

The ECM8000 generic calibration file is from Sonnie's personal ECM microphone that Cross Spectrum calibrated for him.

Of the calibrations that were carried out on this microphone, we chose the Frontal incident (horizontal on-axis 0 degrees), 1/6th octave spacing file and reduced it to two decimal places. It should be fine for home use.

If you require more accuracy, it's best to get your own microphone calibrated.

brucek

**Sonic Icons** · **07-01-09, 01:07 PM**

Thank you for the clarification - the "generic" ECM-8000 calibration file on the downloads page is clearly within range of the response curves shown in #43, if it is understood to be the curve for one particular microphone, rather than an average of all the ECM-8000s tested by Cross-Spectrum.

I agree that the data (the variation of the curves in #43) shows that individual calibration is needed for accurate measurements. Also, it is noteworthy that there is a lot of variation in the deep bass (20 - 100 Hz) (the critical frequency range for measuring subwoofer room response), as well as the highs (5 - 20 kHz).

**cavchameleon** · **07-01-09, 10:28 PM**

Quote:

Sonic Icons wrote:

Thank you for the clarification - the "generic" ECM-8000 calibration file on the downloads page is clearly within range of the response curves shown in #43, if it is understood to be the curve for one particular microphone, rather than an average of all the ECM-8000s tested by Cross-Spectrum.

I agree that the data (the variation of the curves in #43) shows that individual calibration is needed for accurate measurements. Also, it is noteworthy that there is a lot of variation in the deep bass (20 - 100 Hz) (the critical frequency range for measuring subwoofer room response), as well as the highs (5 - 20 kHz).

Yep, as brueck mentioned, it's pretty much fine for the home user, but if you want accuracy, go ahead and get a calibrated one from Cross Spectrum (you'll get it within a couple days of ordering). He has the best price for a calibrated ECM-8000 (there are many mics out there that you can purchase that are calibrated, most being several times the cost of the Behringer, and for most, not necessary.

Ray

**Sonnie** · **07-02-09, 02:05 AM**

To confirm... we have no issues with Herb quoting prices here at the Shack if he so desires.

**cavchameleon** · **07-02-09, 02:49 AM**

Sonnie,
I didn't know if I would be able to quote the price. Since I just purchased it from Herb, here is some info.

Sonic Icons,
Here is Herb's site:
http://www.cross-spectrum.com/measur...behringer.html
You have a choice of to levels of calibration:
1 - Freq response only ($85)
2 - Freq response and Polar Data ($100)

His site has a lot of useful info if you have not checked it out already.

Ray

**JohnM** · **07-02-09, 04:35 AM**

As an aside to all this, with REW V5 the cal data can (ideally should) include phase as well as SPL correction, so should look at including phase data from calibration.

**lcaillo** · **07-02-09, 09:50 AM**

If we were going to do so, would it not make sense to calibrate the mic/preamp as a system, since there may be more phase effect in the combination than just in the mic?

**VintageGold** · **07-03-09, 03:38 PM**

I see you also calibrate the Galaxy CM-140, but along with selling pre-calibrated ECM8000, do you also sell pre-calibrated CM-140's? I'm planning on picking up a CM-140 but wanted to find out if these are available before I purchase from some where like Musician's Friend.

**Anechoic** · **07-12-09, 10:17 PM**

A couple of things:

1. If you ask me a question here and I don't respond within 24-hours, shoot me an email directly and I'll respond here. For some reason I don't always get the thread update emails.

2. Here's a head's up - I offered to do freq-response curves at additional angles for my calibrated mics for free. However, it's become a bit of a hassle to keep track of the various special orders. As a result, I'm going to change things a bit - as of August, I'm going to offer 4 mic models: a) "Basic" with 0-deg freq response for $85, b) "Basic-Plus" with 0/45/90 deg for $90, c) "Extra" with 0-deg freq response, polar, noise floor, and sensitivity for $100 and d) "Extra-Plus" with the "Extra" package + 0/45/90 deg for $110. On the plus side, I'm going to do freq-response down to 5 Hz by default.

This is going to be a price increase but on the plus side, I'll try to stock up on these models so there won't be a wait for people who want the 45/90-deg measurements.

However, I will still do the extra measurements for free for orders placed before Aug 1, so if you want to save some money, place your order before then.

Now on to questions:

Quote:

If we were going to do so, would it not make sense to calibrate the mic/preamp as a system, since there may be more phase effect in the combination than just in the mic?

For my measurements, it doesn't matter since I don't measure phase

.

Quote:

I see you also calibrate the Galaxy CM-140, but along with selling pre-calibrated ECM8000, do you also sell pre-calibrated CM-140's?

I don't sell pre-calibrated meters and I don't imagine I ever will because there are potential liability issues on my end if people purchase it from me for the purpose of using it in a legal setting. However, if you buy a meter, you can have it shipped directly to me, and I'll calibrate it and send it on to you which should at least save a couple of bucks in shipping costs as well as a couple of days of time.

**Dennis H** · **07-13-09, 07:27 PM**

Quote:

Anechoic wrote:

as of August, I'm going to offer 4 mic models: a) "Basic" with 0-deg freq response for $85, b) "Basic-Plus" with 0/45/90 deg for $90, c) "Extra" with 0-deg freq response, polar, noise floor, and sensitivity for $100 and d) "Extra-Plus" with the "Extra" package + 0/45/90 deg for $110. On the plus side, I'm going to do freq-response down to 5 Hz by default.

Do the Basic and Basic-Plus not include 1K sensitivity? Seems like everyone would need that.

**Anechoic** · **07-13-09, 08:41 PM**

Quote:

Dennis H wrote:

Do the Basic and Basic-Plus not include 1K sensitivity? Seems like everyone would need that.

Correct, the Basic and Basic-plus do not include 1 kHz sensitivity. I thought more people would want sensitivity but it turns out that very few people care about - in fact more people want the polar response than the sensitivity.

**Dennis H** · **07-14-09, 09:46 PM**

Quote:

Anechoic wrote:

Correct, the Basic and Basic-plus do not include 1 kHz sensitivity. I thought more people would want sensitivity but it turns out that very few people care about - in fact more people want the polar response than the sensitivity.

That's amazing. How are they measuring SPL? An RS meter that may or may not be within 3dB?

On another subject, can you calibrate above 24K for an extra charge? Many people are using 96K sound cards with a nominal 48K capability so it would be nice to have a general idea what the mic is doing up there, even if the calibration isn't perfect.

**Anechoic** · **07-14-09, 09:51 PM**

Are people using the ECM8000 to measure SPL? I assumed most people were just using them for freq response curves.

The problem with >24kHz measurements is that I don't have calibration curves for my reference mics that go that high. The next time I send in my ref mic for calibration I'll ask them to push the curve out to 40+kHz and then maybe I'll offer the service for an extra charge.

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