S 42C.2 - Loudspeaker Helix - Free user manual and instructions

Product Type	Component speaker system (2-way)
Model	S 42C.2
Brand	Helix
Woofer Size	102 mm (4.01")
Tweeter Size	25 mm (1") silk dome
Power Handling (RMS)	70 Watts
Power Handling (Max)	140 Watts
Frequency Response	75 Hz - 25,000 Hz
Impedance	4 Ω
Efficiency (1W/1m)	89 dB
Woofer Cone Material	Basalt-fiber-paper compound
Tweeter Diaphragm Material	Coated silk dome
Tweeter Housing Material	Aluminum
Crossover Type	Flex-Crossover with 12/12 dB slope, bandstop filter, tweeter protection
Tweeter Level Adjustment	3-stage: -2 dB, 0 dB, +2 dB
Crossover Dimensions	112 x 77.5 x 27 mm (4.41 x 3.05 x 1.06")
Woofer Installation Diameter	92.3 mm (3.63")
Woofer Installation Depth	46.5 mm (1.83")
Tweeter Installation Diameter	45 mm (1.77")
Tweeter Installation Depth	14 mm (0.55")
Mounting Locations	Door, A-pillar, rear deck (ensure adequate space)
Certifications	CE certified
Warranty	Limited warranty per legal regulations; does not cover overload or improper use
Included Accessories	Crossovers, mounting hardware, foam sheets for insulation

Frequently Asked Questions - S 42C.2 Helix

What is the recommended amplifier power for the Helix S 42C.2 speakers?

The speakers handle 70 Watts RMS and 140 Watts max. A quality amplifier delivering 50-100 Watts RMS per channel is recommended for optimal performance.

How do I connect the Flex-Crossover?

Refer to the manual: Option A when tweeter and woofer are close (e.g., door) - connect directly to head unit/amplifier. Option B for separate mounting positions - remove housing, split circuit board, and insulate with foam sheets.

Can I adjust the tweeter level?

Yes, the crossover has a 3-stage tweeter level adjustment: -2 dB, 0 dB, or +2 dB. Open the crossover, remove the acrylic cover, and reposition the jumper to the desired setting.

What is the impedance of the S 42C.2?

The impedance is 4 Ohms.

What are the installation dimensions for the woofer?

The woofer requires an installation diameter of 92.3 mm (3.63") and an installation depth of 46.5 mm (1.83").

Can I separate the crossover for mounting tweeter and woofer in different locations?

Yes, the Flex-Crossover can be separated. Remove the circuit board, take out two jumpers, fold the board into two parts, and insulate each part with the included foam sheets.

What materials are used for the cone and tweeter?

The woofer cone is made of a basalt-fiber-paper compound, and the tweeter uses a coated silk dome in an aluminum housing.

How should I mount the tweeter?

The tweeter can be flush-mounted. Follow the manual: remove the trim ring, insert the tweeter, and secure it. Ensure proper depth and clearance.

Is it safe to cut metal for installation?

Never cut any metal that is an integral part of the vehicle's safety or structural body. Only cut non-structural panels if needed, and ensure proper fitting.

How do I clean the speakers?

Use a soft, dry cloth to gently wipe the surface. Avoid liquids or abrasive cleaners that may damage the cone or tweeter.

USER MANUAL S 42C.2 Helix

Abstract geometric logo with a stylized human figure and a triangular shape (no text or symbols)

HELIX

S 62C.2 / S 42C.2

S 6X / S 4X

Component and coaxial speaker systems

Cross-sectional diagram of a circular mechanical or optical component with concentric layers and central diamond-shaped feature (no text or symbols)

Frequenzweichen

Flex-Crossover S 62C.2 / S 42C.2

S 6X / S 4X

*Alle Abmessungen in mm

Installation

Congratulations on your purchase of this high-quality HELIX speaker system.

This system highlights best quality, excellent manufacturing and state-of-the-art sound quality.

Thanks to more than 30 years of experience in

research and development of audio products this speaker system generation sets new standards.

We wish you many hours of enjoyment with your new HELIX speakers.

Yours

AUDIOTEC FISCHER Team

General instructions

General instructions for installing a HELIX speaker system

To prevent damage to the speakers 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.

For a proper performance and to ensure full warranty coverage, we strongly recommend to get this product installed by an authorized HELIX dealer. If you choose to perform your own installation read the following information and precautions carefully. Failure to follow the stated precautions may result in personal injury and / or damage to the audio system or vehicle.

1. Always make sure that the speaker will fit into the intended mounting location and that there is adequate depth for the magnet system.
2. Check for adequate space between speaker and window, window crank, power window mechanism, seat, rear deck torsion bars, and other items which may interfere with the speaker's mounting. This is very important if any hole cutting is required. Detailed size information is indicated in the dimension section of this manual. Take care that the mounting surface is flat and free from all obstructions.
3. Ensure that the loudspeakers are correctly connected (phase), i.e. plus to plus and minus to minus. Exchanging plus and minus may result in significant loss of sound quality.
4. Make sure that the crossovers are mounted properly.

5. Do not mount the speakers and crossovers where water may splash on them.

6. The quality of the installation has a significant effect on the overall performance of the speaker system. Treat each installation step with a high degree of attention.

7. Avoid low frequency cancellation caused by air leakage between the speaker basket and the mounting surface (e.g. mounted on a bended or uneven surface or mounted in an oversized hole).
8. Mounting panel reinforcement may be necessary in some cases in order to ensure a stable, torsion-free and even surface. This can be achieved by mounting the speaker on a metal or wooden sub-baffle behind the body or door panel. Consult an installation specialist for further advices.
9. In most cases you can use the original speaker mounting locations in the doors, body panels or the rear deck. If these are not available you have to prepare your own secure installation place. Due to their structural integrity and accessibility the precut mounting holes should be used whenever possible. Information on a proper mounting can be found in the section "Installation" of this manual.

IMPORTANT: Never cut any metal that is an integral part of an automobile's safety or structural car body.

General instructions for connecting HELIX speaker systems

We strongly recommend that you operate the complete audio system at low volume before final installation. So you can check whether each speaker is working before securing the loudspeakers into their mounting locations.

General instructions

Make sure that all speaker wiring is fully protected from cutting or wear at sharp edges, which can lead to short circuits that may damage your head unit, amplifier and/or speaker system.

Make sure that all speaker wires are long enough in order to avoid any mechanical stress on the wires or the connectors.

Attention: Ensure that the loudspeakers are correctly connected (phase), i.e. plus to plus and minus to minus. Exchanging plus and minus will result in a significant loss of sound quality.

The positive leads of the loudspeaker system are marked with a red stripe.

General instructions for connecting the HELIX "Flex-Crossovers"

The crossovers of the S 62C.2 / S 42C.2 component system offer two configuration options.

Option a: Connecting the crossovers in vehicles with mounting positions of tweeter and woofer close to each other, e.g. in the car door.

Option b: Connecting the crossovers in vehicles with separate mounting positions of tweeter and woofer, e.g. tweeter in the A-pillar and woofer in the car door.

For further information regarding the connection of the crossovers see section “Connecting the Flex-Crossover” in this manual.

S 62C.2 / S 6B S 42C.2 / S 4B

S 6X S 4X

S 1T

Circular diagram with concentric rings and a central diamond shape, no text or symbols present

Dimensions

Crossovers

Flex-Crossover S 62C.2 / S 42C.2

*All dimensions are noted in mm

S 6X / S 4X

Installation

Woofer mounting

Tweeter mounting
Flush mount

Connecting the Flex-Crossover (S 62C.2 / S 42C.2)

Option a: Mounting positions within close proximity

Connecting the crossovers in vehicles with mounting positions of tweeter and woofer close to each other, e.g. in the car door.

graph TD
    A["HELIX 2-WAY CROSSOVER"] -->|TWEETER - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - *_
    A --> B["Head unit / amplifier"]
    B --> C["WooferTweeter"]

Option b: Separate mounting positions

If the tweeter and woofer are installed separately, e.g. tweeter in the A-pillar and woofer in the car door, it is possible to remove the housing of the crossover and to divide its circuit board for a simplified installation. Proceed as follows:

1. Loosen the screws on the bottom side, remove the acrylic cover and take out the circuit board

1. Remove the two jumpers (blue marked) and then fold the circuit board in the middle into two parts

1. Connection of the crossovers

1. Insulate the divided circuit boards by wrapping them in the included foam sheets or a similar material. The foam sheets are adhesive on the inner side so that each circuit board can be individually wrapped in a foam sheet. Never install the circuit boards uninsulated! Risk of short circuit!

Installation

Adjusting the level of the tweeter: The crossover allows to optimize the level of the connected tweeter internally by repositioning the tweeter level jumper. Therefore loosen the two screws of the crossover housing, remove the acrylic cover, pull the jumper straight upwards and reinsert it to the desired position.

+2 dB: The level of the tweeter is increased by 2 dB.
0 dB: The tweeter has the optimum level for most applications.
-2 dB: If you choose this switch setting, the level of the tweeter is reduced by 2 dB.

Connecting the separate crossover of the coaxial systems

graph LR
    A["Head unit / amplifier"] --> B["Heico"]
    B --> C["Woofer Tweeter"]
    C --> D["+"]
    C --> E["-"]
    C --> F["+"]
    C --> G["-"]

Ensure that all components are correctly connected (phase), i.e. plus to plus and minus to minus. The positive leads of the loudspeaker system are marked with a red stripe.

Features

• Woofer with novel basalt fiber-paper compound cone – a perfect combination of lowest weight, high stiffness and inner damping
• 1" / 25 mm silk dome tweeter in a noble aluminum housing (S 6X: 25 mm / S 4X: 19 mm) for balanced, natural sound reproduction and lowest compression effects
• Individual HELIX basket with additional ventilation holes for better voice coil cooling and high power handling
• S 62C.2 / S 42C.2: "Flex-Crossover" with 6/12 dB (S 42C.2: 12/12 dB) slope, bandstop

filter and three-stage tweeter level adjustment – separable and therefore well suited for the installation in vehicles with separate mounting positions of the tweeter and woofer

• S 62C.2 / S 42C.2: Crossovers solely equipped with high grade components e.g. low-distortion air-core coils and minimum-loss Audiotec-foil capacitors for tweeter crossover
• S 6X / S 4X: Separate inline crossover with 6/12 dB (S 4X: 6/6 dB) slope and integrated tweeter protection

Component systems:

	S 62C.2 S 42C.2
Power RMS / max. 100 / 200 Watts 70 / 140 Watts
Frequency response 45 Hz - 25,000 Hz 75 Hz - 25,000 Hz
Impedance 4 Ω 4 Ω
Efficiency 1 W / 1 m 90 dB	89 dB
Cone material	TW: Coated silk domeW: Basalt-fiber-paper compound	TW: Coated silk domeW: Basalt-fiber-paper compound
Crossover	6/12 dB with bandstop filter,tweeter protection and tweeter level adjustment	12/12 dB with bandstop filter,tweeter protection and tweeter level adjustment
Dimensions crossover	112 x 77,5 x 27 mm /4.41 x 3.05 x 1.06"	112 x 77,5 x 27 mm /4.41 x 3.05 x 1.06"
Outer diameter	TW: 51 mm / 2.00"W: 165 mm / 6.50"	TW: 51 mm / 2.00"W: 102 mm / 4.01"
Installation diameter	TW: 45 mm / 1.77"W: 143 mm / 5.63"	TW: 45 mm / 1.77"W: 92.3 mm / 3.63"
Installation depth	TW: 14 mm / 0.55"W: 65 mm / 2.56"	TW: 14 mm / 0.55"W: 46.5 mm / 1.83"

Coaxial systems:

	S 6X	S 4X
Power RMS / max. 80 / 160 Watts	60 / 120 Watts
Frequency response 50 Hz - 25,000 Hz 80 Hz - 25,000 Hz
Impedance 4 Ω 4 Ω
Efficiency 1 W / 1 m 90 dB	89 dB
Cone material	TW: Coated silk domeW: Basalt-fiber-paper compound	TW: Coated silk domeW: Basalt-fiber-paper compound
Crossover	Separate, 6/12 dB slope	Separate, 6/6 dB slope
Dimensions crossover	58 x 49 x 24 mm /2.32 x 1.96 x 0.94"	58 x 49 x 24 mm /2.32 x 1.96 x 0.94"
Outer diameter	165 mm / 6.50"	102 mm / 4.01"
Installation diameter	143 mm / 5.63"	92.3 mm / 3.63"
Installation depth	65 mm / 2.56"	46.5 mm / 1.83"

Warranty Disclaimer

The limited warranty comply with legal regulations.

Failures or damages caused by overload or improper use are not covered by the warranty.

Please return the defective product only with a valid proof of purchase and a detailed malfunction description.

Technical specifications are subject to change!

Errors are reserved! For damages on the vehicle and the device, caused by handling errors of the device, we can't assume liability. All HELIX speakers are tagged with a CE-Certification mark.

Thereby these devices are certified for the use in vehicles within the European Community (EC).

AUDIOTEC

FISCHER