It's 25 x 24 with 8.5 ceiling and not treated.

https://www.google.ca/amp/s/www.hometheaterforum.com/community/threads/under-1000-subwoofer-review-thread.343857/%3famp=1446124323?espv=1

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated