Elipson Classic Sub 12

In a large living room, floorstanding speakers often start to lose steam around 40 Hz, and it is below this limit that you find the rumble of an explosion in a film, the lowest note of an organ or the sub-bass of an electronic production. The largest model in Elipson’s Classic Sub range entrusts this final octave to a 30 cm driver and 300 W of amplification, in a black cabinet weighing over 20 kg with an understated design and simple controls.

A 30 cm driver powered by 300 W of Class D amplification

The 300 mm driver radiates forward, behind a removable grille, and uses a fiberglass cone, a composite that is both rigid and lightweight. This rigidity matters in a subwoofer: to reproduce 30 Hz at high levels, the cone travels several millimeters back and forth, and a material that is too flexible would deform during this movement, resulting in less defined bass and audible distortion. Here, the radiating surface moves as a single unit, like a piston.

The 300 W amplifier operates in Class D, a switching technology that converts almost all the energy consumed into useful power. It generates little heat, takes up little space in the cabinet and keeps power in reserve for soundtrack peaks.

The cabinet uses a bass-reflex design: a port, a type of tuned duct, recovers the wave emitted by the rear of the cone and brings it back into phase to reinforce the bass around its tuning frequency. Internal braces stiffen the walls, which would otherwise vibrate under the air pressure and add their own resonances to the sound. The unit’s 20.4 kg weight, resting on feet that isolate it from the floor, gives an idea of the panels’ thickness. The finish is black, with no other options.

Reaching down to 25 Hz: digital boost and protection filter

The frequency response extends from 25 to 160 Hz at ±3 dB, placing the subwoofer in the region where you feel the pressure in the room more than you hear it. To achieve this with a reasonably sized cabinet, digital signal processing (DSP) boosts the region around 33 Hz by 6 dB. Human hearing loses considerable sensitivity at these frequencies, especially at moderate volume, and this boost maintains a perceptible foundation even during evening listening.

This gain has a physical cost worth knowing about: an extra 6 dB at a given frequency requires four times as much electrical power at that frequency. The 300 W are therefore called upon more heavily around 33 Hz than elsewhere, and at very high levels in a large room, this is the region where the reserve runs out first.

The subsonic filter completes the setup. Set to 23 Hz with a slope of 12 dB per octave, it gradually attenuates everything below this frequency. In a bass-reflex design, below the tuning frequency, the port no longer restrains the cone and its excursion increases very quickly. Yet these inaudible frequencies exist in certain soundtracks, in the undulations of a warped record or when the furniture is knocked: the filter removes them before they push the driver to its excursion limit.

Matching the subwoofer to your speakers and amplifier

The crossover frequency is adjustable from 40 to 160 Hz. It sets the upper limit of what the subwoofer reproduces, and getting it right determines how well it blends with the main speakers. With floorstanding speakers that already reach low frequencies, a crossover set around 40 or 50 Hz leaves the subwoofer handling only the deepest bass. With more modest bookshelf speakers, a value of 80 Hz or above avoids a dip between the end of their response and the start of the subwoofer’s. The top of the range, at 160 Hz, is useful when a home theater amplifier handles bass management itself: the subwoofer’s crossover is set to maximum so that it does not overlap with the amplifier’s filtering.

The two-position phase selector (0° and 180°) reverses the cone’s movement. Depending on the distance between the subwoofer, the speakers and the listening position, the bass waves from the two sources can reinforce each other or partially cancel out at the crossover frequency; one of the two positions produces fuller bass, and that is the one to keep.

Connectivity is limited to low-level stereo line inputs and outputs. The subwoofer therefore connects to a preamp output or a subwoofer output on an integrated amplifier, a network amplifier or a home theater receiver. Automatic standby switches off the amplification when there is no signal and reactivates it as soon as the music or film resumes.

The largest model in the Classic Sub range

The Classic Sub range comprises three 8-, 10- and 12-inch subwoofers, all featuring fiberglass cones, Class D amplification and bass-reflex enclosures. Compared with the Classic Sub 10 (250 mm, 200 W, 29 Hz, 15.4 kg), the Classic Sub 12 gains 4 Hz of sub-bass extension and 100 W of power. These figures may seem modest, but in a large room, the additional cone area moves noticeably more air and remains comfortable at levels where a 25 cm driver starts to strain.

The dimensions follow suit: 356 mm wide, 422 mm high and 470 mm deep, increasing to 486 mm with the grille in place. The depth, close to half a meter, is the first figure to check before planning a spot alongside a sofa or next to a TV stand.

Technical specifications

Design and amplification

• Type: active bass-reflex subwoofer
• Amplification: 300 W, Class D
• Driver: 300 mm diameter, fiberglass cone

Acoustic performance and settings

• Frequency response (± 3 dB): 25 to 160 Hz
• Subsonic filter: 23 Hz, 12 dB/octave slope
• Crossover frequency: variable from 40 to 160 Hz
• Bass boost: + 6 dB at 33 Hz
• Phase: 0° / 180°
• Standby: automatic

Connectivity

• Line inputs: left / right, low-level
• Line outputs: left / right, low-level

Dimensions and weight

• Dimensions (width × height × depth)
  • Without grille: 356 × 422 × 470 mm
  • With grille: 356 × 422 × 486 mm
• Net weight: 20.4 kg
• Gross weight: 23.6 kg