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Full SPL Correction Chart


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5 replies to this topic

#1 of 6 Kerry Hackney

Kerry Hackney

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Posted December 26 2001 - 03:45 AM

Looks like several people got a new SPL meter for Christmas. I sat down with Excel and the standard correction chart and filled in all of the values from 10 to 100 HZ in 1 Hz. steps using the growth function in the software. If anyone is interested drop me an email and I'll send it to you.Posted Image

#2 of 6 Kerry Hackney

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Posted December 27 2001 - 01:35 AM

Well heck,
for those of you who don't speak Excel here is the numbers. This is non-linear growth progression. I can do a linear one when I have a chance but I decided this was probably closer to actual. My thanks to people who did the original work to provide reference points. I certainly don't want to take credit for that.


10Hz.+20.50
11Hz.+18.80
12Hz.+17.23
12.5Hz.+16.50
13Hz.+15.67
14Hz.+14.13
15Hz.+12.75
16Hz.+11.50
17Hz.+10.33
18Hz.+9.29
19Hz.+8.35
20Hz.+7.50
21Hz.+6.92
22Hz.+6.38
23Hz.+5.88
24Hz.+5.42
25Hz.+5.00
26Hz.+4.62
27Hz.+4.27
28Hz.+3.95
29Hz.+3.65
30Hz.+3.38
31Hz.+3.12
31.5Hz.+3.00
32Hz.+2.97
33Hz.+2.91
34Hz.+2.84
35Hz.+2.78
36Hz.+2.72
37Hz.+2.67
38Hz.+2.61
39Hz.+2.55
40Hz.+2.50
41Hz.+2.26
42Hz.+2.18
43Hz.+2.09
44Hz.+1.99
45Hz.+1.90
46Hz.+1.81
47Hz.+1.73
48Hz.+1.66
49Hz.+1.58
50Hz.+1.50
51Hz.+1.50
52Hz.+1.50
53Hz.+1.50
54Hz.+1.50
55Hz.+1.50
56Hz.+1.50
57Hz.+1.50
58Hz.+1.50
59Hz.+1.50
60Hz.+1.50
61Hz.+1.50
62Hz.+1.50
63Hz.+1.50
63Hz.+1.50
64Hz.+1.50
65Hz.+1.50
66Hz.+1.50
67Hz.+1.50
68Hz.+1.50
69Hz.+1.50
70Hz.+1.50
71Hz.+1.50
72Hz.+1.50
73Hz.+1.50
74Hz.+1.50
75Hz.+1.50
76Hz.+1.50
77Hz.+1.50
78Hz.+1.50
79Hz.+1.50
80Hz.+1.50
81Hz.+1.52
82Hz.+1.54
83Hz.+1.57
84Hz.+1.59
85Hz.+1.61
86Hz.+1.64
87Hz.+1.66
88Hz.+1.68
89Hz.+1.71
90Hz.+1.73
91Hz.+1.76
92Hz.+1.78
93Hz.+1.81
94Hz.+1.83
95Hz.+1.86
96Hz.+1.89
97Hz.+1.92
98Hz.+1.94
99Hz.+1.97
100Hz.+2.00
Posted Image

#3 of 6 Jim J

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Posted December 27 2001 - 03:08 AM

Which meter are you discussing here?

the standard Radio Shack Analog?
Jim J

#4 of 6 Kerry Hackney

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Posted December 27 2001 - 05:09 AM

Jim,
Yes, this is for the standard analog meter. The chart is based on the work originally done by Michael Sims of the
Prairie State Audio Construction Society. The original posts concerning his work are available here through the search engine. Look for "meter correction" and you should find them.

#5 of 6 Dustin B

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Posted December 27 2001 - 05:59 AM

Will this also work with the Digital RatShack meter?
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#6 of 6 Kerry Hackney

Kerry Hackney

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Posted December 27 2001 - 08:09 AM

Dustin,
You would have to look into the original work done by Prairie State Audio to see for sure. The test I saw makes mention of him using two analog units and one digital one and that they were all pretty close. If the analog and digital one share the same microphone you would most likely be safe in using these numbers. Hopefully, someone else may have a more definitive answer.

The downside as I understand the digital version is that it doesn't display reading any finer that 1 db. It would be nice if it did tenths. At least with the analog version you can guess at the finer scale.