rted Design Round Port Specs (Inner Domeier x Length) 1 Overhead Cutaway View NOTE: The M101B5 Marine Subwoofer is not recommended for use in Ported Enclosures. Port Information Tune to: (Hz) F3 (HZ) M1OWS 16.5 m.x 13.5 m. x 14 in. 419mm x 343 mm x 356mm 3 in. x 13 in. 76 mm x 330 film Round port