My goal is to stop the low bass from playing on my stand-mounted speakers so they can concentrate their efforts on the mid bass on up.
If that’s your goal, a high pass filter is a must!
Since your integrated amp not possible to insert a line level high pass filter, your only option is to insert a pair of speaker level high pass filter between the speaker and integrated amp speaker output.
SU-G700 speaker output --> speaker level high pass filter --> Canton 9K
You can find some inexpensive speaker level high pass filter at Parts-express for experiment:
https://www.parts-express.com/100-hz-high-pass-4-ohm-crossover--266-460
For best result, I suggest Bi-wire configuration:
Disconnect the jumper bars from the Canton 9K speaker terminal,
connect the speaker level high pass filter input to integrated amp speaker terminals, output to Canton 9K low frequency terminals,
connect the Canton 9K high frequency terminals direct to integrated amp speaker terminals, so the high frequencies will not go through the speaker level high pass filter.
If you like the result of this setup, you can upgrade the capacitor in the speaker level high pass filter to Film Cap to further improve sound.
https://www.parts-express.com/pedocs/tech-diagrams/266-460--crossover--schematic.pdf