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using the Radio shack SPL meter

I got a digital Rad Shak SPL meter the other day. I'm trying to figure out just how to use it. At this point all I want to do is find out how loud is loud, for me.

I got it set to the C weighted setting. Set the Range to 80db, and then on to 90db.

Pointed it straight ahead fixing it at the listening position where my head would be and turned up the music. Slowly..Stopping now and then.

At a level surely loud enough for me, and off 85-86db speakers, the highest number shown on the meter was 91-92db.

Given the +/- 10% variation the gizmo is professed to have, does this mean I was listening to 91-92db, or 100-101db? Or 82-83db?

While on the 100 range the numbers remained the same with 91-92db still the highest numbers reflected on the screen at the loudest level I could stand, without worry of gear issues or for just brief periods like a single song or at best two. They’d need be short ones as well.

I've done nothing else. In fact whatever those numbers actually represent, it was certainly too loud for extended listening. IMO. I didn’t turn it up past that level either... though it may have produced greater numbers. From repairs or on the meter.

Checking the vol knob later I had some more room to go but not safely as I was about the 1-2 o’clock position on the preamp.

I heard no audible clipping or distortion at any time.

How loud was I listening?
blindjim
blindjim OP
3,092 posts
 
I think it was set to AVG. I know it was fluctuating up and down, either at the.2 sec or .5 second intervals.

Is there a function setting to measure this particular aspect with?

Also, how can one find out about the diffs indicated in the literature as to the actual eff of the meter, as Ive heard more than one say "Accurate within 10%"... or did that only apply to the analog meters?
jaffeassc
166 posts
 
The + or – 10 db indicates the range that the meter is reading. For example if the meter was set at 90 it would read from 80db to 100db. That’s why you got the same reading of 91 – 92 db whether the meter was set at 90 or 100. So it sounds like you were listening at 91 – 92db. The only thing you did not mention was whether you had the MAX button set, which would indicate that the meter was only displaying the loudest measured sound level during the sampling period.
shadorne's avatar
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shadorne
7,477 posts
 
The digital radio shack meter is not a precision instrument. I don't think you can trust the absolute "accuracy" of readings to more than +/- 3 db SPL between roughly 50 HZ and 5 Khz. I read somewhere that the 10 db errors you talk about are at extremes of 20 Khz or at 20 Hz.
montytx
138 posts
 
I seriously doubt that your meter is off by 10%. At the frequency extremes this would be believable, but at avg. listening levels, what the meter said was likely very close to what you were hearing.

Btw, I too find SPLs in excess of about 90db at the listening level to be way too loud. Peaks of 90-95 are about as high as I can tolerate. Even then, only for a particularly favorite song.
swampwalker's avatar
swampwalker
5,138 posts
 
I know that when I was setting up my Velodyne SMS-1, and was supposed to get an 82-83 dB level, it was quite a bit louder than I usually listen.
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