Topic: What on earth happened here?

[opsopcopolis]

Remember, it depends greatly on where the measurement is made.  145dB in the throat of the compression drivers of the PA isn't out of the question at all.. but at the soundboard? No way.

Safe assumption that we mean in the house

[Gutbucket]

"In the house" doesn't tell us enough.  We need to know where in the house.

tl;dr-  If you want to boast how loud your band is, measure right up against the PA, rather than "out in the room somewhere", because sound level decreases rapidly with distance.

http://www.sengpielaudio.com/calculator-SoundAndDistance.htm
"The sound pressure decreases in inverse proportion to the distance, that is, with 1/r from the measuring point to the sound source, so that doubling of the distance decreases the sound pressure to a half (!) of its initial value"

Which means in this case.. (values derived using the appropriate calculator on that webpage) :

If its 145dB one foot in front of the stack (stack humper doing the measuring)..
it will be 125dB ten feet away (tweakers by the speakers)..
119dB twenty feet away in the (up impact zone)..
113dB forty feet away (call that the SBD)..
etc..

^Granted that describes the freespace condition (such as an open air outdoor concert).  In an enclosed room things behave essentially the same way up to the critical distance, which is a measure of the distance from a source where the level of the level of direct-arriving sound equals that that of the reverberant sound, beyond which the reverberant sound dominates over direct sound and sound pressure levels off.

[Gutbucket]

The excerpt below from the Shure recording guide explains this better than I have-

Direct vs. Ambient Sound – A very important property
of direct sound is that it becomes weaker as it travels
away from the sound source, at a rate controlled by the
inverse-square law. When the distance from a sound
source doubles, the sound level decreases by 6dB. This
is a noticeable audible decrease. For example, if the
sound from a guitar amplifier is 100 dB SPL at 1 ft. from
the cabinet it will be 94 dB at 2 ft., 88 dB at 4 ft., 82 dB
at 8 ft., etc. When the distance is cut in half the sound
level increases by 6dB: It will be 106 dB at 6 inches and
112 dB at 3 inches.

On the other hand, the ambient sound in a room is at
nearly the same level throughout the room. This is because
the ambient sound has been reflected many times
within the room until it is essentially non-directional.
Reverberation is an example of non-directional sound.
This is why the ambient sound of the room will become
increasingly apparent as a microphone is placed further
away from the direct sound source. The amount of direct
sound relative to ambient sound can be controlled by the
distance of the microphone to the sound source and to a
lesser degree by the polar pattern of the mic.
However, if the microphone is placed beyond a certain
distance from the sound source, the ambient sound will
begin to dominate the recording and the desired balance
may not be possible to achieve, no matter what type of
mic is used. This is called the “critical distance” and
becomes shorter as the ambient noise and reverberation
increase, forcing closer placement of the microphone
to the source.

https://www.shure.com/damfiles/default/global/documents/publications/en/performance-production/microphone_techniques_for_recording_english.pdf-bb0469316afdb6118691d2f3f5e3ff01.pdf

[jerryfreak]

I hope your neighbors don’t mind you blasting 110db at home 

From the horse’s mouth:

a good answer by him as every recorder has different voltage and current specs for its PIP