# Measure sound level with ECM8000 and REW?



## xntricity (Sep 26, 2012)

Hi Folks,

I have been given the task at work :foottap: measure sound level from the fan's on our product to demonstrate to customers using a GUI.

I dont need anything too costly , just a general indicator. I have been looking at the SPL meters but are a little costly.

*My plan !!*

1.Use REW software > SPL meter > Logger > Db Spl graphed

2.Behringer ECM8000 mic

3.XLR to USB Mic Converter/Mic Preamp (Blue Microphones Icicle)

Am i going down the right road here, or am i way off the mark :spend:

Thanks for any guidance that may come my merry way :whistling:


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## wgmontgomery (Jun 9, 2011)

Although REW does measure SPL, it must be calibrated to get an accurate measurement. Based on your post, you don't need anything fancy; you'll probably end-up spending more on the items listed than you would on a simple SPL meter. 

Check-out these; they are not expensive and should work well for your intended use.

...and welcome to HTS!! :wave:


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## xntricity (Sep 26, 2012)

Thanks for you help :wave:

Hope i can interface soud level meter with REW, I will check out pricing of a SLM with some form of usb communications

: )


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## Wayne A. Pflughaupt (Apr 13, 2006)

xntricity said:


> I have been given the task at work :foottap: measure sound level from the fan's on our product to demonstrate to customers using a GUI.


If SPL levels are all you interested in, then you only need a SLM with a line output that can feed a signal directly to REW. The ECM mic, pre-amp etc. is only relevant or necessary if you want to take accurate full-range frequency response measurements.

Now, if you’re interested in the _relevant frequencies_ of the fan noise, and need to plot them, that might be a different story. But even then, a typical C-weighted meter has reasonably flat response from 40 Hz to 3 kHz, which should adequately cover even frequency-specific fan noise. Only if you need greater accuracy above and/or below 40 Hz - 3 kHz do you need to move up to a calibrated mic and associated pre-amp.

Regards, 
Wayne


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## xntricity (Sep 26, 2012)

Hi Wayne,

For this demonstration for customers the results measured by mic will have to be similar to spec's set out by our documentation.

Our measurments were taken with a SLM meter with A weighting db range from 37-59db for fan noise level.

specific Frequency levels were not really taken into account.

After checking SLM meters i dont think real time analysis can be fed from SLM tru USB to REW software, mabey i am wrong here. I was hoping to avoid anything going tru laptop soundcard.

If i am correct i will go with the ECM8000 and USB to XLR converter, I can use our inhouse SLM to referance ECM8000 and get things generally calibrated.

I have to purchase equipment today so hope i am going the right direction : )


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