Helix IK S12 – DVC2 – 2 x 2 Ohms

Helix IK S12 – shallow 300 mm / 12″ subwoofer for flat, compact enclosures

Version: DVC2 – 2 x 2 Ohms

The Helix IK S12 is the 12-inch member of the HELIX IK S series, Audiotec Fischer’s family of shallow-mount subwoofer chassis. It is intended for flat and compact enclosures where mounting depth is the limiting factor – with an installation depth of only 95.5 mm it opens up enclosure designs that a conventional woofer cannot fill, without acoustic compromises according to the manufacturer.

Despite the slim build, HELIX pairs large voice coils with a low resonance frequency to achieve bass that the manufacturer compares with much larger woofers. A very stiff sandwich paper cone and a heavy-duty motor system turn amplifier power into sound pressure without compression while still resolving fine low-frequency detail. A threaded hole in the back of the magnet lets the installer bolt the woofer to the enclosure’s rear panel, which stiffens shallow boxes and reduces panel vibration even with thin walls.

Key Features

• Very low installation depth: 95.5 mm mounting depth, made for compact and flat enclosures.
• Two voice coil versions: Available as SVC2 (1 x 2 Ohms) or DVC2 (2 x 2 Ohms) to suit a wide range of amplifier wiring options.
• Rear magnet mounting thread: Threaded hole in the magnet for bolting the driver to the enclosure back panel – more rigidity and less enclosure vibration.
• Sandwich paper cone: Very stiff cone construction for compression-free conversion of amplifier power into sound pressure.
• Heavy-duty motor: Strong drive with a 50.8 mm voice coil and low resonance frequency for deep bass from a small chassis.
• Long-excursion rubber surround: Supports a linear excursion (Xmax) of ±8.0 mm and high mechanical load capacity.
• Protective magnet cover: Robust cover with HELIX lettering protects the magnet assembly.
• Power handling: 300 W RMS / 600 W max (DVC2 data).
• Gold-plated enclosure terminal: High-quality connection terminal with gold-plated screw terminals is included.
• Complete DIY package: Grille and gasket included; the data sheet provides sealed and vented enclosure recommendations including DSP settings.

Drivers & Construction

• Nominal size 300 mm / 12″; outer diameter 316 mm / 12.44″.
• Cone material: sandwich paper cone; effective cone area (Sd) 523 cm².
• Voice coil: 50.8 mm diameter, 24 mm winding height.
• Long-excursion rubber surround and protective magnet cover with HELIX lettering.
• Magnet with rear threaded hole for fixing to the enclosure back panel.

Acoustic Performance

The figures published on the product page refer to the DVC2 (2 x 2 Ohms) version; values for the SVC2 version are given in its separate data sheet.

• Power handling: 300 W RMS / 600 W max.
• Impedance: 2 x 2 Ohms (DC resistance 2 x 1.8 Ohms).
• Sensitivity: 91.0 dB @ 2.83 V / 1 m; 88.0 dB @ 1 W / 1 m.
• Resonance frequency (Fs): 36 Hz.
• Q factors: Qms 5.41, Qes 0.52, Qts 0.48.
• Equivalent air volume (Vas): 40 l; compliance (Cms) 95 µm/N.
• Force factor (Bxl): 17.2 Tm; moving mass (Mms) 220 g; mechanical resistance (Rms) 7.9 kg/s.
• Maximum linear excursion (Xmax): ±8.0 mm.

Installation Notes

• Installation (cut-out) diameter: 276.8 mm / 10.90″; installation depth: 95.5 mm / 3.76″.
• Recommended sealed enclosure (DVC2): 22 l net volume, -3 dB at 39 Hz; suggested DSP high-pass 35 Hz (Q 1.5) plus EQ 75 Hz, Q 1.5, -3 dB.
• Recommended vented enclosure (DVC2): 40 l net volume, port Ø 100 mm (78 cm²), 32 cm long, tuned to 36 Hz, -3 dB at 37 Hz; suggested DSP high-pass 36 Hz (Q 1.0) plus EQ 75 Hz, Q 0.7, -2 dB.
• For shallow enclosures, use the threaded hole in the magnet to brace the driver against the rear panel.

Technical Specifications

Scope of Delivery

1 x Subwoofer HELIX IK S12-DVC2
1x Grille
1 x Gasket
1x Enclosure connecting terminal
1 x Data sheet