What does the exclemation mark left of the dB indicate?

[codingchipmunk]

Hello everyone,
I have always had issues with equalizers and PulseAudio, where increasing the loudness of frequencies led to distortion / scratching. The same happened when using the EQ from easy effects, only that - thanks to the status bar - I now know that this only happens when dB get positive. Also, easy effects shows an exclamation mark besides the dB when this happens.

So, independent of my audio issue, I would like to ask if the exclamation mark pops up if there is an actual issue with PulseAudio and / or its configuration or just shows up when dB are greater than 0 (unfortunately there isn't any tooltip on mouseover).

[wwmm]

or just shows up when dB are greater than 0

That is it. Before sending the signal to the sound card EasyEffects measures its level. This is what is shown in its bottom bar. If the level is above 0 dB the warning in the image is shown so the user can know the signal level is in a dangerous zone. It is in general fine to have the level above 0 dB in the other plugins level meters. But you do not want the output level in the bottom bar to get this high because this what your soundcard is going to get.

[wwmm]

Based on your image you are definitely applying too much amplification. That is not safe for your soundcard or your health. In most cases it is better to do what is called "subtractive equalization". Instead of amplifying the frequencies you want to be boosted reduce the level of the ones that you want to be attenuated. In you image you would keep the low frequencies gain close to "0 dB" and use a negative gain for the others you kept at zero gain.

[wwmm]

If the output audio level is too low you can always use the output gain slide at the bottom to compensate the reduction. It is better than applying such a large gain to each frequency band.

[wwmm]

And if all you want is too boost the bass a little it may be easier to just use the bass enhancer plugin instead of the equalizer that is harder to set properly.