I would say Yea. Because the only speaker that I know that has 15ohm and 83db spl ratings with the Falcon name attached is their Rogers LS 3/5a speakers. After 40 years and many speakers have come and gone, I still love Rogers.
Now that you mention. I do switch between 8ohm Quads with 86ish?db spl and the Rogers. I don't hear any significant loudness between them with the same volume setting on the preamp.
However, I did hear a hear a level difference when I went from a tube amp using the 16 ohm tap to the SS Spectral amp I'm using now. I just figured it was the differing input sensitivity of the amps.
Why? I don't know. I just listen to the music. I do use the Quads for large orchestral. The Rogers for near field critical listening, smaller quintets, jazz or solo recordings.