@kalibri @ext23 On the topic of the SPL readings (which vexed and irritated me greatly a couple months ago), I've noticed the following (on recent/up-to-date firmware):
Without EQ, the SPL readings seem plausible to me
. I have no way of verifying the numbers, but they correspond roughly to what I'd expect and, say, those hearing safety charts that list the decibel levels of common noises. The number under "Volume" seems to be the max possible SPL, but if you navigate to "Input" you can see "Level RMS" and "Sound Pressure" which seem to be two different ways of displaying the 5K's actual estimate for the
current volume.
But as soon as I turn EQ on (which, in my test case, is an EQ profile for the Sennheiser IE200 with a
-6 db pre-amp) the readings
totally break.
Here's the before and after. Within the same song, the estimate goes from 79 decibels to 87 decibels. This is during the same stretch of a song, with very similar volume.
The 87 decibels being the EQ profile
with a -6 db pre-amp. This is obviously absurd and inaccurate. I've actually lowered the volume by at least 6 decibels, and yet somehow the Qudelix reports an 8 db increase. Which is actually mild, as far as this issue is concerned.
I've noted up to as much as a 15 db increase between the reported volume pre-EQ and post-EQ, during subjectively similar loud portions of music. And we're not talking classical music with huge dynamic range here; just standard modern music with a modest or low variation between the quietest and loudest portions of a song.
Note the large variation in the Level RMS (dB) reading. You might think the screencaps are captured during a much quieter part of the song, but that's not the case. If I'm guessing, the -6 db pre-amp is being factored into the Level RMS (dB) reading. And yet somehow the "Sound Pressure" rises dramatically, though the music is actually much quieter as soon as I activate the EQ with -6 db pre-amp (naturally).
These are my observations. If anyone with more technical acumen can explain
why this is happening (assuming it's not just a bug/broken readings from Qudelix) I'd be appreciative.
But the TLDR is: SPL readings seem ballpark accurate without EQ, but as soon as I use an EQ profile the readings are totally worthless.