# Bruel & kjaer 2238 mediator



## Karicas (Jun 29, 2014)

Hi there,

Can anyone help me for microphone selection?

I have the ECM8000 witch as i see is a good mic for use with REW.
i´m wondering if it will be a value use my Bruel & kjaer 2238 mediator as mic.
i´m using a Edirol 25, or maudio fast track usb sound cards.


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## gazoink (Apr 17, 2013)

Interesting that you have that meter and yet are asking this question. Got a manual? The Aux 1 output provides a range-adjusted, unweighted or weighted AC signal from the mic, 1V full scale, basically line level. The mic, being it's a B&K and all, should be pretty flat. If you don't mind the somewhat cumbersome instrument, and the somewhat odd Lemo connector used for the Aux 1 output, there are several advantages to using it as your mic. First, it's flat, wouldn't require a mic cal file. Second, the preamp in the meter is pretty quiet, so the weighted noise floor is 14dBA, and it would take some doing to achieve that with an inexpensive mic and your preamps. But the big advantage is, the thing is already calibrated, so you have absolute SPL done for you. The only disadvantage I see is the connector and the physical size of the unit. It probably has a 1/4-20 thread tripod mount too, right?


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## Karicas (Jun 29, 2014)

First tank´s for your response,

Of course the 2238 in that matter is a beast.
The problem is that if it is worth using the 2238 for this kind of stuff. 
Initially thought about selling the B & K and use the ECM8000. 
The B & K is supported by clear and tripod is much better as a microphone as I could already see using XTA RT1 real time spectrum analyzer.
keeping the B&K is only if it is worth for that matter.


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## a.pavonibelli (Sep 25, 2012)

I can tell you this: I too have a 2238 BK and in comparison with the ECM 8000 connected to a M Audio Fast Track Ultra, on Leq (A) measurement, I found a difference of about 1 dB. The ECM was calibrated with the BK calibrator 4231, the same on the SLM. So, if you need a precision measurement, is better to use the BK mediator, with the output Aux1. When the anecoic room of the research insyitute where I work (INRIM, Turin, Italy) wil be free (now is used for different measurement), i plan th calibrate the ECM on frequency response in comparison with the our BK national standard microphones (BK, of course, calibrated on 0.02 dB).
Best regards.


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## idea53 (Jan 17, 2014)

Does anyone know what type of Lemo connector is used on the AC output? 
B&K wants 150 € for a Lemo to BNC connector. The salesperson said that he had learned to tell their prices without being ashamed...
One zero to much for my liking since I managed to get my hands on a 2238 and a class 1 calibrator for 200 €.


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## Karicas (Jun 29, 2014)

Hi,

This it will be great.
In my case e can´t see the need of using resolutions off 0,02DB since it is not necessary for home use.
Of course a good calibration of the ECM800 it´s a very good idea comparing the prices of the 2 equipments.

Rui Martins


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