Subwoofers — Jamo C912Sub

The C912 SUB is the larger member of the Jamo Concert 9 subwoofer pair. Compared with the C910 SUB, it adds cone area and amplifier power inside a taller and deeper reflex enclosure, and it accepts the same optional wireless kit as its smaller sibling. Jamo describes it for use in both home cinema and stereo music systems, and the current range offers it in Matte White.

Key specs that matter

A 300 mm long stroke woofer with an Injection Moulded Graphite cone handles the bass, powered by Class D electronics rated at an output of 200 W and a maximum of 400 W. Response within plus or minus 3 dB spans 29 Hz to 125 Hz, while output is 6 dB down at 25 Hz. Maximum level is quoted as 114 dB at 1 m. The low-pass filter adjusts from 40 Hz up to 200 Hz, and phase can be set to 0 or 180 degrees. The enclosure stands 454 mm tall, 356 mm wide and 480 mm deep and weighs 14.5 kg without packaging. Jamo lists universal mains operation at 100 to 120 V and 60 Hz or 220 to 240 V and 50 Hz.

Engineering and use context

The graphite-loaded cone is made by injection moulding, a process Jamo uses across the Concert 9 subwoofers to combine low mass with a rigid diaphragm. Set against the C910 SUB, the larger cone and amplifier come with a maximum level 4 dB higher and a -3 dB point 3 Hz lower. Woofer and reflex port both open on the front panel of this enclosure, so rear clearance is not needed for the port to work. Behind, a WA-2 socket takes the optional Jamo WA-2 wireless system. It sends the signal over 2.4 GHz for distances up to roughly 15 m, and is compatible only with Jamo subwoofers that carry the WA port. Jamo states that the link runs with ultra-low latency.

Pairing

Line-level connection runs through dual RCA sockets labelled L/LFE and R. A surround receiver or processor connects with one cable from its subwoofer pre-out to the L/LFE socket, which passes both music and film bass, whereas a two-channel integrated lacking that jack may drive the pair of RCA inputs from both of its preamplifier outputs. If crossover duties are left to the receiver, the subwoofer filter should be turned to its top position so it stays out of the way. As a starting point, the manual gives 50 to 90 Hz for large floorstanders and 90 to 150 Hz where the mains are small stand-mount or satellite models, with smaller main speakers needing a higher value.

Alternatives

The Jamo C910 SUB offers the same Concert 9 construction with a 10 inch IMG woofer and 150 W rated amplification in a 400 mm tall cabinet.