This isn't making any sense at all, I repeated everything I did with the Denon same CD and the same distance and I got 85dBs at volume 10
Its making sense to me.
Your main speakers have two 5.25" drivers in each of your towers.
Sensitivity is quoted at 90 db 2.83 volts 1 meter. The nominal impedance is 8 ohm, however they are 2.5 ways with a stated minimum impedance of 4 ohms, so they are in effect 4 ohm speakers. You can go to the bank with that. The other thing that gives it away is the way the sensitivity is specked. On a 1 watt I meter rating they would be 3db less sensitive, below 500 Hz anyway.
Now your receiver is rated 90 watts into 8 ohms. Four ohm rating is not specified. However if it is typical of receivers of that class it will deliver 45 watts per channel into those speakers at most. Then don't forget at least half of that power is lost in the crossovers, and probably more.
The maximum peak power those small drivers can handle is 150 watts. So if you were to buy a power unit that can provide 150 watts into a four ohm load you would increase your peak power readings by 4.5 to 5 db in your current room at your listening position.
I don't know the volume of your room but I can tell it is not small.
I think people expect too much spl from small diameter drivers powered by receivers below $1000 in the 90 to 100 watt class in any decent sized room.
I just measured my spl to give you a comparison.
I just played an organ SACD via the analog inputs of my pre pro.
At -5 db it was impressive but clean and did not sound overly loud, but it was. You have to be careful with this rig because it does not sound stressed at high spl. It sounded as if you were right in front of the organ pipes. Peaks were 95 to 96 db. The soft passages around 50 db average. At -10 db is was peaking around 90 db and still too loud. It was above the level in a listening position in the cathedral.
At -18 db it was peaking around 75 db probably a little low. That disc sounded optimal at -14 db.
Next a CD of the Russlan and Ludmilla overture. I obtained pretty much the same results, although peaks were around 96 db at -5 setting. Full concert volume was probably around -14 db , but I usually play at around -18db.
Now my mains have two 10" drivers and two 7.5 inch drivers in each main. each main is powered by 450 watts. The two ten inch drivers are fed from active crossovers, so the power is actually equivalent to 600 watts of power if the crossovers were all passive. In any event I have at least 10 times more power available to my mains than you. The sensitivity is pretty much identical to your speakers although the bass section is about 6 db more sensitive.
So this should put it in perspective.
First always put quality and accuracy before spl. If you want to achieve, and really feel you need to achieve 90 db plus listening levels, then your upgraditis will have to extend to amps and speakers.
And as I stated previously you can not expect whole house audio from one set of speakers. That is not practical.