I want a usable SPL (sound pressure level) meter app for my Android (OS 8 version) phone.

MikeRivers

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Dec 21, 2014
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I can't find an SPL (sound pressure level) meter that works properly at loud levels - where it's really needed..

On my older phones (OS 4 and 6) I was using an app from Audio Control which disabled the AGC on the audio input AGC so that, when properly calibrated, it could measure SPL greater than 100 dB. Unfortunately, it doesn't run on my current phone - a Moto G6 Play - and the app has been abandoned by the developer for the usual reason - "there are so many Android versions that we can't support them all."

The problem with all the other SPL apps that I've tried is that the AGC/limiter sits on the level coming in from the mic (external as well as internal) so that the app doesn't know that what the mic is hearing is louder than about 80 dB. A few of them can be calibrated to indicate fairly accurately between about 50 and 80 dB SPL (at lower levels, the AGG boosts the level from the mic) but between 80 and 105 dB (yes, I wear ear protection when I'm testing!) the limiter kicks in hard and the meter stays right around 80 dB.

Surely there must be a hook, probably undocumented, for controlling the AGC or limiter. Is there any hope, or must I go back to carrying my Radio Shack SPL meter on gigs?

By the way, the best currently available app I've found is http://keuwl.com/SPLMeter/ but it has the same problem. I've e-mailed the developer a couple of times but never received a response, not even a "you can't do that."
 
The app you link to has a calibration option. You may be able to use that to trick the app by making it think that the level is lower than it is. Wouldn't work if you needed low level accuracy but may get you under the limiter. You will have to correct for the discrepancy on the fly.