Helix’s complete powered-sub upgrade in one box: the IK E8.1-DVC2 MK2 8″ downfire enclosure plus the Impact ISM 400.2DSP amplifier module that plugs straight into it. The ISM replaces the enclosure’s passive connection terminal, turning it into a self-contained active subwoofer with its own amplifier and sub DSP. It’s made for adding proper bass to a factory sound system without rebuilding the rest of the system.

What the DSP actually does

The ISM’s DSP is not a multichannel processor for your whole system. It is one channel of processing dedicated to the subwoofer, and most of its job is automatic EQ, so the sub fits the car instead of fighting it:

• Reads the factory signal and cleans it up. The Advanced Input Signal Analyzer (AISA) analyses the signal coming from the factory system, which usually already has the car maker’s own EQ and filtering applied, and the input EQ corrects it, so the sub starts from a clean signal.
• Automatic EQ. Helix’s TuneEQ function adjusts the input, virtual and output equalisers automatically.
• Puts back the bass the factory took out. Helix’s DeepImpact algorithm restores the low end lost to the high-pass filtering in factory systems. With a full-range signal it reacts to the music, adding bass only where a track lacks impact.
• Starts from a matched setting. DSP PC-Tool 6 includes presets for Helix’s IMPACT enclosures.
• Extras: Dynamic Loudness Control, Remote Tone Control and Augmented Bass Processing.
• Already have a DSP? The DirectDSP switch sends the input straight to the amplifier with no processing, so the ISM works purely as a powerful sub amp.

The amplifier

The amplifier is Class HD: 2 x 200 W RMS at 2 Ohms (up to 460 W RMS maximum at 2 x 2 Ohms), with high efficiency and low heat. The heavy-duty highlevel input takes up to 32 V, so it picks the signal up safely even from factory amplifiers. ADEP.3 keeps modern factory head units free of error messages, and it switches on automatically from the music signal, so no remote wire is needed. It is EV Ready, with a start-stop capable supply from 10.5 to 18 V, and a power save mode for when no music is playing.

The enclosure

The enclosure is the IK E8.1-DVC2 MK2: a compact downfire ported box with one 8″ / 200 mm Helix IK W8-DVC2 driver with a hand-scooped paper cone, port-tuned to 43 Hz. Firing into the floor spreads the bass evenly around the car and keeps the driver protected. It is rated at 300 W RMS, measures 184 x 310 x 290 mm, and stands on feet with Velcro pads in a hard-wearing carpet finish with an embroidered Helix logo.

Every DSP we sell includes a free 1 hour base tune set-up at our workshop. Get in touch to book it.

Both parts are also sold separately: the Helix IK E8.1-DVC2 MK2 enclosure (£189.99) and the Helix Impact ISM 400.2DSP module (£509.99), so you can start passive and add the ISM later.