Subwoofers — Mission MS-450 Sub

The MS-450 is one of four current MS subwoofers from British brand Mission, whose manual presents the MS family as the latest in a long line of its active subwoofers. The other three are the MS-150, MS-200 and MS-400. Its rear panel marks it as a UK-engineered product built in China, and the owner's manual is dated December 2017.

Key specs that matter

Mission fits one 15 inch or 380 mm long-throw cone, fed by a 400 W amplifier. Mission gives the frequency response as 25 Hz to 150 Hz within 3 dB, with the crossover adjustable from 40 Hz to 150 Hz. Average maximum output is 124 dB at 1 m. For full output the line input needs 200 mV, the stereo input impedance is 10 kohm and the LFE input 5 kohm, and hiss stays at least 85 dB below the signal. The cabinet is 460 mm wide, 530 mm high plus 58 mm of feet and 560 mm deep. Net weight is 32.5 kg and the packed carton weighs 36.5 kg, so Mission advises two people for lifting and never dragging the unit across the floor.

Engineering and use context

The amplifier is an ultra-fast balance-drive Class D design matched to a specially developed long-throw bass unit, and Mission describes the system as an active Dynamic-Drive IB subwoofer. The driver fires down or forward, a layout chosen to couple the bass with the room and distribute it evenly. On the back panel sit the crossover dial, a volume control, a phase switch with 0 and 180 degree positions, an auto sense switch, the line and LFE inputs, a mains switch, an IEC mains socket and a fuse holder for a T3.15AL 250 V fuse. With auto sense off the subwoofer stays permanently on, while the auto setting lets it switch itself on and off with the signal. The unit is a Class II double insulated appliance, so it needs no earth connection, and the version covered by the manual runs on 220 V to 240 V at 50 or 60 Hz, with a panel rating of 650 W.

Pairing

The manual covers three hookups - one screened RCA cable running from a processor's LFE jack, Y adaptors between the pre out and main in sockets of a separable stereo amplifier, or a stereo RCA cable from spare preamp outputs. Because there are no speaker-level terminals, a source without any line output cannot drive it. The deep extension and high output ceiling make it a match for large floorstanding speakers in stereo as well as for 5.1 and 7.1 cinema layouts.

Alternatives

The Mission MS-400 is a smaller MS subwoofer with a 250 mm driver, a 215 W amplifier and a 35 Hz to 120 Hz response in a 14.6 kg cabinet.