I recently added a KRK S10.4 subwoofer to my home recording studio to help my Kali IN8 near field monitors out at the low end.
KRK: https://www.krkmusic.com
Setting up KRK sub: https://s3.amazonaws.com/gibsonproa...
KRK S8.4 review: • KRK S8.4 Subwoofer review