# Help with SPL meter and sound card



## Cortes (Sep 3, 2012)

My first post here, so hi everyone :R 

I recently bought the mic ECM8000 broadly recommended here. After spending a whole afternoon with my DAC with pre-amp, valve integrated, and old usb card Waveterminal U24 I finally figured out what "phantom power" means :sweat:

So the most convenient option to measure/improve my room is to spend even more money and buy a new USB card with Phantom Power incorporated. And later a SPL meter, which adds to the total. 

My question is whether I can get the job 'well' done with a cheap card such as M-Audio Fast Track or Pre, or instead I should shot for a more expensive option, like the Roland UA-55. Measurments are more reliable with better cards (and therofore pre-amps built it) ?. Are the difference relevant?. Will one get a better treated room with better cards/SPL meters?.

Roland UA-55 Quad-Capture ~ $260
M-Audio Mobile Pre Mk II ~ $146
M-Audio Fast Track MKII ~ $91

Another question, here in Europe is not that easy/cheap to get the highly recommended Galaxy CM-140, because of that I was thinking in some other options, like PCE 322A or Ominitronic SLM-500, class II both and A,C weighted. Will I run into troubles using this less knowns SPL meters?, Will I need any callibration file for them that I can't find on these forums or the internet?.

Thanks. 



*PCE Instruments PCE 322A~ Euro 128 in amazon.es

*OMNITRONIC SLM-500 SPL-Meter ~Euro 110 in amazon.de


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

Welcome to the Forum, Cortes!

According to a knowledgably fellow who used to frequent this forum, there’s no appreciable difference in any USB audio interface (meaning a soundcard with built-in mic pre-amps) under $400, as far as anything relevant to REW is concerned. You might want to check the  REW Soundcard Database for recommendations that are compatible with your operating system.

Regarding the SPL meter, the only reason to opt for the CM140 – and a calibration file for it - would be if you intend to use it as a measurement mic, which is facilitated by its line output. Since you’re going to use the ECM8000 for that purpose, all you need is a basic meter. Get the cheapest one you can find.

And actually, you don’t even need a meter. It’s useful for REW’s SPL calibration routine, which enables (and insures the accuracy of) the program’s built-in SPL meter. With a proper SPL calibration, the vertical-axis dB indications of the frequency response graph that REW generates are accurate. But you can use REW and generate accurate and usable response graphs without the SPL calibration. For instance, there will still be a valid 10 db difference between say, the 75 and 85 dB indications, even if the actual numbers are off. Hope this makes sense...

Regards, 
Wayne


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## Cortes (Sep 3, 2012)

Wayne A. Pflughaupt said:


> Welcome to the Forum, Cortes!
> 
> According to a knowledgably fellow who used to frequent this forum, there’s no appreciable difference in any USB audio interface (meaning a soundcard with built-in mic pre-amps) under $400, as far as anything relevant to REW is concerned. You might want to check the  REW Soundcare Database for recommendations that are compatible with your operating system.
> 
> ...


Hi Wayne,

thanks a lot for your very detailed response. It clarifies all my doubts, and now I understand the whole thing much better. 

Best regards.


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