My God, man. This is incredible.
I don't need MEASUREMENTS to tell me how these systems work -- what are you not getting about this?
I LITERALLY added six decibels to a speaker, went into the master volume and cranked it up AS A TEST -- the available volume value was reduced by SIX. Every time I added dBs, this happened in reaction. I need scientific tests for that? Are you kidding?
And what do you even know about my setup at that point? How do you know it was "poor"? I said I was doing experiments to see if the overall master volume would be lowered in reaction to +dB boosts, and it WAS.
And you DID in fact suggest that places like Reddit are "full of nonsense," so you did, in turn, suggest that preference was "nonsense," too.
I do think you are making a fuss over an issue you are going to have to get used to.
I have stayed away from getting involved with this, but I think you have forced my hand. The issue is changing standards for audio normalization in terms of distribution of media especially over the Internet.
Let me just clear the air and say that the number your volume reads is irrelevant as long as you can get it loud enough.
Now let's get to the nub of the problem which is audio normalization for the distribution of audio and AV media. These are evolving and this will bring about changes in level as to where you set your volume control.
The issue was brought to a head vai Dolby over control of the distribution of Atmos streams over the Internet.
Now there has been a standard for the normalization of audio streams. Historically this has been -18 LUFS. AES and the European Broadcast Union have come to the view that -18 LUFs is too loud and does not allow for the wide dynamic range afforded by digital media. In other words they wanted a lower normalization level to allow higher dynamic range without compression. This is especially important for classical music opera etc.
So EBU 128 was adopted in 2023 which lowered normalization to -23 LUFS. That will effectively lower average levels by 6 db. Now Dolby are vigorously enforcing EBU 128 of -23 LUFS for Dolby Atmos streams and insist streams not normalized to -23 LUFS be pulled.
At first I was concerned by this but have come to realize this was the correct decision. The BPO are now trending their stream to the same -23 LUFS as their Atmos streams. I note the BBC have trended their streams to EBU 128. I for one am now strongly in favor of normalization to EBU 128. When I now send out a Wav. file of work I have done, I now send it normalized to EBU 128. This actually allows for a much higher quality stream and essentially zero dynamic compression without saturation.
So you are all going to notice lower average levels on streams going forward. I am now convinced that this produces far better and more realistic reproduction, you just have to turn up the volume. Whereas the old streams used to have my volume set to -13 to -14 db. On these newer compliant streams the volume is now set to -7 to 9.5 db. The only downside of this change is that it requires rigs have superior signal to noise ratio. Otherwise low db passages will descend into the background.
The is the long version of why the OP has noticed a different scale setting on his newer AVR as I suspect the designers to be adjusting to new standards, which I expect to be enforced in the near future.
So the OP just needs to advance his volume control to get his desired spl. Resistance is useless, so get used to it.