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Discussion Starter · #1 ·
Hi all. I've been measuring the SPL using the logger over 4 hours; I'm using "A"weighted and fast response and saving the data using "time of day". I've then saved the measurements which becomes a text file. Now the measurements in the text file: what are they as they are minus measurements and are not at all like the decibel readings that were being shown in the logger graph? How do I recalculate them back to be the decibel readings ?
cheers Louise from Tasmania Australia
 

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Welcome to Home Theater Shack, lgrant. We are happy you chose to join us! :clap:

I am not sure about the format of the data, but I am sure someone will provide the answer soon, or John will know.
 

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Hello and welcome to the forum. :bigsmile:
 

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I just tested the SPL logger and the file shows the indicated dB results. So:

Are you using the current REW 5.01 beta 17 version? I am guessing not as there was a change in beta 8 to change from "db FS" to "dB" in the logger.

If you were using a older version of REW than beta 8 and need to recovery the data that you saved it is still possible. REW recorded the "dB FS" that is dB relative to full scale dB. It is the same value as is shown on the small bar meter on the REW SPL Meter below the large numerical dB readout. The actual dB values can be calculated simply by adding the negative numbers recorded to the maximum SPL number given at the top of the file. So if the maximum SPL is reported in the header as 105.35 dB and the recorded value in the table is -45.25 dB FS then the value you want is the 105.35 + -45.25 which is just 105.35 - 45.25 = 60.10 dB. A spreadsheet program would be very handy for this job!
 

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Discussion Starter · #6 ·
Thanks for that. I'll try tonight (Australian time!). I thought I downloaded the new version but I'm now not sure so I'd better check when I retrieve my equipment from measuring today. cheers Louise
 
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