Radio Shack Sound Level Meter

A test was conducted using two B&K Sound Level Meters, model No.2203, and a Radio Shack Sound Level Meter. The measurements were performed in a room with noise from street traffic and computers. The signal level was in the range of 55-76 dB and always above the ambient noise. The signals were generated with a set of two small speakers, positioned two meters apart. The sound level meters were located on a couch with microphones protruding from its edge. The signals used in this test were the STS signals from the AUDIO-CD. The purpose of this test was to determine how consistent measurements can be obtained with those sound level meters and how they will depend on the sound level meter used in the test and its position in the room. Measurements were done on a slow "C" scale. One of the B&K meters was used as a reference (assuming an exact measurement of, say, 80 dB SPL). The other B&K meter and the Radio Shack meter were measured against it. Therefore, in the table below, only deviations from the measured level of 80 dB SPL are shown. The B&K calibrator was used first to check both the reference B&K meter and Radio Shack meter. The calibrator generates 94 dB sound at 1000 Hz. The reading from the B&K meter was 95.5 dB and on the Radio Shack meter it was 94 dB (Bravo Radio Shack !). Frequency [Hz] (STS signals) B&K (SPL deviation [dB]) Radio Shack (SPL deviation [dB]) 125 250 500 750 1 k 1.5 k 2 k 3 k 4 k 5 k 6 k 7 k 8 k 9 k 10 k 11 k 12 k 14 k 16 k 18 k 20 k +1.0 +1.0 -4.5 +1.0 +5.0 +1.5 -2.5 +2.0 -0.5 +0.5 +2.5 +2.5 +2.0 +3.0 +6.0 +4.0 +4.0 +1.0 0.0 0.0 0.0 -3.5 -0.5 +4.5 +2.0 -1.0 +1.5 -1.0 +4.0 +2.5 +4.5 +3.0 +5.5 +4.0 +3.0 +2.5 +1.5 +4.0 +2.0 +4.0 +2.5 +1.0 Deviations Min. 0.0, Max.6.0 Deviations Min. 0.5, Max.5.5 SPL [dB] = 80 dB + deviation - sound level measured by the meter deviation = (error of the reference meter) + (error of the meter) + (difference of the level due to the different positions of the sound level meters in the sound field) Conclusions: Taking into consideration all sources of the potential error the SPL level deviations are very small. Therefore, the STS signals can be used for the free-field testing, especially if the environment is controlled, leading to a better distribution of intensities in the sound field. The results from the Radio Shack Sound Level Meter are very impressive taking into consideration the fact that the meter costs only about $49.99 Can. It appears that this meter can be used in some situations that demand less accuracy with a high level of confidence. Certainly, it can be used to check the free-field levels created by STS signals from the AUDIO-CD.

Symbols / Terms Used: Hz - unit of frequency dB - unit of SPL SPL - Sound Pressure Level STS - Special Test Signal (described as part of AUDIO-CD) Sound Level Meter - instrument to measure SPL B&K - Bruel & Kjaer Ltd., Denmark

Test your Hearing Online WWW Hearing Test the first comprehensive and entirely web-based hearing test

Terms of Use | Return Policy | Privacy Policy

Copyright (©) 1996-2014 by Digital Recordings. All Rights Reserved. No part of the information provided on this www page may be reproduced for any purpose, in any form, without prior written approval.

This site uses frames. To enjoy them your screen's resolution should be at least 800 x 600, preferably 1024 x 768. To invoke frames click here.