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Discussion Starter #1
Hi,

The only sound level meter that I see on the Radio Shack site is #33-099. Will this work with REW or would I be better off finding one of the meters shown in the help file (33-2050, 33-4050, 33-2055)?

Thanks,

Steve
 

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I did not look up the catalog number, but I assume that is the digital one, right? They have not made the analog ones in a while. I also assume you are using the meter as a microphone for REW. If that is the case, the type of display does not matter. Be sure to find the RS meter calibration curve and put it into REW to compensate for the meter's freq response errors.

One of the SpectraCal calibrated mics will do a better job. But, it requires a phantom power supply. You can get by with an inexpensive mic mixer, but together that will run you $125-150 or so. If that is OK, it will give you more accurate results for freq response measurements.
 

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What are you trying to get measurements on? If your looking to do full range none of the Radio shack meters will do a good job as they roll off after about 3kHz If your looking for a better meter the Galaxy CM140 is a good choice but again it rolls of at about 12kHz
 

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Thanks to both of you for your replies. This #099 meter looks to be a new digital model unlike any I see pictured in the REW help files. radioshack.com/product/index.jsp?productId=12680845#stuff-you-want

I was planning to use this as a microphone for REW for more of a full range measurement. I'll check out your suggestions. Thanks for your help!

Steve
 

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Radio Shack has both a new analog meter and a new digital meter.

I actually just bought a friend the new RS meter for his bday, slowly and surely getting him into real HT. I did a side by side comparison with my old digital RS meter and the new one, using the same (old) cal file... I would not use the old digital RS cal file for the new meter. Judging by the smaller orifice I'm guessing the newer RS meter should be better to a higher range than the old digital meter, which they say is only good up to about 3kHz.






Here is the arbitrary FR comparison: re-calibrated SPL for either, using same .cal file, no smoothing. This isn't a very technical comparison, just a gee-whiz glance:

 

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Thank you fuselli! I have this new, smaller orifice SPL meter as well, it is definitely the only one radio shack sells now.

It is good to know that the old digital calibration file is off by so much, 10 dB in the low end it looks like. I have a calibrated EMM-6 on the way, but in the mean time I have been using this SPL as a mic with a tascam 144mk2.

Your graph, I think, explains why when I run an SPL calibration at 75dB using this meter as the input and meter, they lose sync by 10 dB when the room is silent. IE the radioshack mic shows 35dB and REW shows 45dB on the built in SPL meter (or it may be the other way around, I forgot).

I am assuming REW's built in SPL meter utilizes the mic calibration file....

Fusseli, would you please send me those graphs so I can "semi-properly" adjust the old digital digital RS meter cal file to work with this new one?

Thanks.
 

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I am hesitant to post this just because it could have an air of officialness to it, because they are measurements. Keep in mind mic positioning was not exactly duplicated, among other things such as variance in measurements from mic to mic (even mics of the same model won't measure EXACTLY the same). In addition to that, I re-calibrated SPL between either measurement so a side by side comparison would be visible. I would recommend waiting for a new .cal specific to the new meter.

In other words, take this with a hefty grain of salt. Here is "old - new," with and without smoothing:
 

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Thanks. You're right I should wait for something official. Did you do any testing above 3k to see if these new meters can handle it?
 

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No, since I have nothing to compare it to it's impossible to distinguish what's in the measurement and what's coloration from the mic.
 

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its all in how the hardware is implemented. Digital is far more acurate simply because you can see decimal points much clearer than analog but again its all dependent on its design. The one I use (Galaxy CM140) has a certification that it is accurate.
 

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bump to this thread... im new here and i already owned the 33-099, im wondering if there is a .cal file thats been added since the last post of this thread some 3 1/2 years ago?

Thank you
 
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