Well done, Charles1dad. The devil is in the details. I tried some Focal 936 towers because they listed at 8 ohms, 92 dB sensitivity. However, when one looks more closely:
"My estimate of the Focal’s voltage sensitivity was 89.5dB(B)/2.83V/m—close to the specified 90dB, and usefully a little higher than average. The Aria 936 is specified as having a nominal impedance of 8 ohms and a minimum impedance of 2.8 ohms; my measurement (fig.1) confirmed the minimum value at 108Hz, but as the impedance stays below 4 ohms from the upper bass though the lower midrange, where music has high levels of energy, I would recommended using a amplifier rated into 4 ohms with this speaker." (JA in Stereophile)
https://www.stereophile.com/content/focal-aria-936-loudspeaker-measurements