.
The manual for the CF61 shows the speaker with a power rating of 120 watts @16 ohms. Most speaker ratings show their power at 8 ohms. The 16 ohm rating of the speaker will probably cut your amplifier output by almost 1/2.
The wattage does not change because of the impedance.
The 16 ohms would cause the sensitivity to be 3 dB down as compared to a 8 ohm driver.
As long as the amplifier can deliver the proper power-then it is not an issue.
I bet the reason for 16 ohms is so that you can hook up multiples to a single amp channel. As many as 8.
With 8 ohm speakers you could only hook up 4.
Also with a 16 ohm speaker you will have less loss across a given speaker cable length and the damping factor will be twice as high as an 8 ohm.
This probably doesn't matter in the case in question, but are things that are often overlooked.
There advantages and disadvantages to higher and lower impedance loudspeakers.
It all comes down to the particular situation and the gear being used that makes one preferable than another.