What kind of VU , dB ?

[pcar75]

Bonjour,

On reading about volume levels (Sound On Sound magazine 2024May/"Enjoy the VU" and 2003October/Q&A/"Are all Decibels equal?" and various web entries) I am curious about what exactly do the tracks bar-graph levels represent. When playing guitar, I aim to stay about the 2 yellow bars of my Input track. I think this is Ok but what level does that correspond to ? (Note that I'm no sound engineer !)

Thanks for any info !

[ann0see]

This won't answer your question fully, but see

jamulus/src/global.h

Lines 199 to 206 in f965518

	// range for signal level meter
	#define LOW_BOUND_SIG_METER ( -50.0 ) // dB
	#define UPPER_BOUND_SIG_METER ( 0.0 ) // dB
	// defines for LED level meter CLevelMeter
	#define NUM_STEPS_LED_BAR 8
	#define RED_BOUND_LED_BAR 7
	#define YELLOW_BOUND_LED_BAR 5

where the levels are defined and

jamulus/src/levelmeter.cpp

Line 194 in f965518

if ( iLEDIdx < YELLOW_BOUND_LED_BAR )

where the change to yellow happens.

In end effect, I'd just trust what others and my ears say.

[pcar75]

Thanks, So do I. But it's just out of curiosity ...
So the comments on the code would indicate -50 to 0 dB in 9 segments (0-8 , given C/C++ indexing )
of approximately 11.1% each. Linearly that would use 5,6 dB per segments, however the scaling could be logarithmic.
From some other sources, these would be dBFS or dB Full Scale I suppose, as used in most audio DAW.