I have my Emu 1820M optical output going into an Onkyo TX-SR500 reciever,
out to two Sony SS-B3000 3-Way bookshelf speakers.
https://docs.Sony.com/release//specs/SSB3000_mksp.pdf
1" tweeter, 3" midrange, 8" woofer
The crossover is not specified in specs.
Also, Sony support says they don't have the info.
There are options that need to be selected, such as Optical In 1, of course.
But also select number of speakers/configuration (2 speaker stereo)
You can select crossover frequency,(80hz, 100hz, 120hz)
but it does not effect it if Subwoofer Off is selected.

I am familiar with Room Eq Wizard, and wondering where in the measurement data
I would be able to decipher the crossovers.

Thanks.