https://www.sanus.com/en_us/products/speaker-stands/sfc18/
I would start here instead of using that Ekhorn signature base ottoman. Definitely can’t be doing you any favors.
You have plenty of room for subwoofers. They make some pretty good micro subs these days look at REL acoustics https://rel.net/?gad_source=1&gclid=CjwKCAiA8Lu9BhA8EiwAag16b-0UmMU6_C4w4cqO9pxfo4jHIj3lF5-gPpbeJ6Ce36PPqek1pV2pZxoCjbQQAvD_BwE
also try setting up the speakers manually instead of using the room correction feature.