HELIX P TWO 2-Channel High-Res Amplifier

General Instructions

To prevent damage to the unit and possible injury, read this manual carefully and follow all installation instructions. This product has been checked for proper function prior to shipping and is guaranteed against manufacturing defects.

Before starting your installation:

• Disconnect the battery's negative terminal to prevent damage to the unit, fire and/or risk of injury.
• For proper performance and full warranty coverage, installation by an authorized HELIX dealer is strongly recommended.
• Install your P TWO in a dry location with sufficient air circulation for proper cooling.
• Secure the amplifier to a solid mounting surface using proper hardware.
• Carefully examine the mounting area to ensure no electrical cables, hydraulic brake lines, or fuel tank components are present behind the surface.
• The amplifier may only be installed in vehicles with a 12 Volts negative terminal connected to chassis ground. Other systems could cause damage.
• The positive cable from the battery should have a main fuse within 30 cm of the battery. Fuse value depends on total system current draw.
• Use only suitable cables with sufficient cross-section. Fuses must be replaced with identically rated fuses (3 x 30 A) to avoid amplifier damage.
• Plan wire routing to avoid damage, crushing, or pinching hazards. Protect cables from sharp edges and avoid routing near potential noise sources.

Connectors and Control Units

Description of the amplifier's connection points and controls:

1. Highlevel Input:

High-level speaker inputs for connecting to factory or aftermarket radios without low-level line outputs.

2. Line Input:

RCA inputs for connecting low-level line signals.

3. Clipping LED:

Lights red if any input is overdriven. Reduce gain (Control 4) until the LED turns off.

4. Gain:

Adjusts input sensitivity for Line, Highlevel, and Optical inputs (2-8V for Line, 5-20V for Highlevel, 0-12dB for Optical). Recommended Highlevel setting is ~9V (9 o'clock position).

5. Remote Control:

Input for the included cable remote control for volume adjustment (only active in bandpass mode).

6. HPF Frequency:

Adjusts the high-pass filter crossover from 15 Hz to 4,000 Hz. Active when X-Over is set to HPF or BPF.

7. X-Over:

Switch to select filter modes: HPF (Highpass), FULL (Fullrange, bypasses filters), BPF (Bandpass, HPF is always active). Bandpass requires careful setting of HPF and LPF frequencies (at least two octaves apart).

8. LPF Frequency:

Adjusts the low-pass filter crossover from 15 Hz to 4,000 Hz.

9. Bass Boost Frequency:

Sets the center frequency for bass boost (40 Hz - 120 Hz).

10. Bass Boost Gain:

Adjusts the bass boost level from 0 to 9 dB.

11. Input Mode:

Routes input signals to amplifier channels (Stereo, Stereo Summed, Mono).

12. Optical Input:

SPDIF input for digital stereo signals (28 - 96 kHz). Digital signals are typically not volume-controlled; use volume-controlled sources. Handles stereo PCM signals only.

13. Output Channels:

Speaker outputs. Minimum impedance per channel is 2 Ohms. Do not bridge or parallel outputs.

14. Fuse LED:

Indicates amplifier status: Green (ready), Red (malfunction), Flashing Red (overheat), Flashing Red/Green (fuses blown).

15. GND:

Ground connection point.

16. REM:

Remote connection for turn-on signal. Not needed for Highlevel Input if head unit has BTL outputs.

17. +12 V:

Power connection to battery positive. Requires appropriate wire gauge and inline fuse.

18. Auto Remote:

Activates/deactivates automatic turn-on via high-level inputs. Deactivate if noise occurs; REM connection becomes mandatory if deactivated.

Initial Start-up and Functions

Highlevel Input: Connects directly to speaker outputs. Features ADEP circuit for radio diagnostics. Auto turn-on enabled; REM connection not needed. Use provided screw-terminal. Do not use Highlevel and Line Input on the same channel simultaneously.

Line Input: Connects to low-level outputs. Auto turn-on does not work; REM connection is mandatory. Do not use Highlevel and Line Input on the same channel simultaneously.

Clipping LED: Lights red when input is overdriven. Reduce gain (Control 4) until LED turns off.

Gain: Adjusts input sensitivity. Recommended Highlevel setting is ~9V (9 o'clock position).

Remote Control: Connects to included remote for volume control (active only in bandpass mode).

HPF Frequency: Sets high-pass filter crossover (15 Hz - 4,000 Hz). Active when X-Over is HPF or BPF.

X-Over: Selects filter mode (HPF, FULL, BPF). Bandpass requires careful setting of HPF and LPF frequencies (at least two octaves apart).

LPF Frequency: Sets low-pass filter crossover (15 Hz - 4,000 Hz).

Bass Boost Frequency: Sets bass boost center frequency (40 Hz - 120 Hz).

Bass Boost Gain: Adjusts bass boost level (0 - 9 dB).

Input Mode: Routes signals (Stereo, Stereo Summed, Mono).

Optical Input: SPDIF input. REM connection mandatory. Digital signals are not volume-controlled; use volume-controlled sources. Handles stereo PCM signals (28-96 kHz) only.

Output Channels: Speaker outputs. Minimum impedance 2 Ohms. Do not bridge or parallel outputs.

Fuse LED: Status indicator (Green: ready, Red: malfunction, Flashing Red: overheat, Flashing Red/Green: fuses blown).

GND: Ground connection.

REM: Remote connection. Not needed for Highlevel Input if head unit has BTL outputs.

+12 V: Power connection to battery positive. Requires appropriate wire gauge and inline fuse.

Auto Remote: Enables/deactivates auto turn-on via high-level inputs. Deactivate if noise occurs; REM connection mandatory if deactivated.

SPDIF Direct In Switch: Bypasses input stage for direct digital signal routing. Requires opening unit and setting switch to "On". X-Over must be "Full". Highlevel/Line inputs and Gain control are disabled.

Installation

Connecting the lowlevel line inputs: Use RCA/Cinch cables. Channel A for mono. Stereo/Stereo Summed for both channels. REM connection is mandatory.

Connecting the highlevel speaker inputs: Connect directly to speaker outputs. Channel A=Left, B=Right. Auto turn-on works; REM not needed if head unit has BTL outputs. Ensure correct polarity.

Connecting a digital signal source: Use Optical Input. REM connection mandatory. Use "Stereo" or "Stereo Summed" Input Mode. Use volume-controlled sources.

Configuration of the digital signal input (optional): Route digital signal directly by setting SPDIF Direct In to "On" and X-Over to "Full". Affects only Optical Input.

Adjustment of the input sensitivity: Crucial for preventing damage. Use Gain control (4). Adjust until Clipping LED just turns off.

Connection to power supply: Disconnect battery first. Connect +12V to battery positive with an inline fuse. Use appropriate wire gauge and ground cable.

Connecting the remote input: Connect REM to radio remote output if using Line or Optical inputs. Not needed for Highlevel Input if head unit has BTL outputs.

Configuration of the remote input: Auto turn-on via Highlevel or REM. Auto Remote switch controls this. Deactivate if noise occurs; REM connection mandatory if deactivated.

Connecting the loudspeaker outputs: Connect directly to speakers. Never connect to chassis ground. Ensure correct phase (+ to +, - to -). Minimum impedance 2 Ohms per channel. Do not bridge or parallel outputs.

Unique Features of the HELIX P TWO

• Ultra HD Class D amplifier technology: Extended frequency response (>40 kHz), reduced distortion, Class AB sound quality with Class D efficiency.
• Signal converters with a native resolution of 32 Bit: High-precision signal conversion, especially for lower signal levels.
• Smart highlevel input: ADEP circuit prevents radio diagnostic errors and feature loss.
• Start-Stop capability: Maintains stable operation even with voltage drops down to 6 Volts during engine crank.

Examples for Speaker Configurations

2-channel fullrange application: Component system with Highpass filter (50-100 Hz).

2-channel subwoofer application: Subwoofer with dual voice coil, Bandpass filter (Highpass ~15 Hz, Lowpass ~80 Hz).

2-channel subwoofer application in combination with HELIX P SIX DSP MK2: Connection via digital audio cable. Crossover frequencies adjusted via DSP PC-Tool. To deactivate P TWO filters, set X-Over to "FULL" and SPDIF Direct In to "ON".

Note: Recommended highpass filter settings vary by speaker size (e.g., 50 Hz for 16.5 cm, 70 Hz for 13 cm, 100 Hz for 10 cm).

Technical Data

Warranty Disclaimer: Limited warranty complies with legal regulations. Excludes damages from overload or improper use. Returns require prior agreement, original packaging, detailed description, and proof of purchase. Technical specifications are subject to change. No liability for damages caused by handling errors. Certified for use in the European Community (EC).

Manufacturer Information

Audiotec Fischer GmbH
Hünegräben 26 · 57392 Schmallenberg · Germany
Tel.: +49 2972 9788 0 · Fax: +49 2972 9788 88
E-mail: helix@audiotec-fischer.com · Internet: www.audiotec-fischer.com