Focal HILO V3 | High-Level to RCA Converter with Impedance Simulator
Add an Amplifier While Retaining the Factory Head Unit
The Focal HILO V3 is a high-quality high-level to low-level converter designed to simplify the connection of an aftermarket amplifier to a compatible factory audio system.
Many original vehicle head units do not provide the RCA preamp outputs normally required by an aftermarket amplifier. Instead, they send an amplified speaker-level signal directly to the factory speakers.
The HILO V3 converts a two-channel amplified speaker signal into a clean stereo low-level RCA output. This allows a compatible amplifier to be added while retaining the original radio, infotainment display, steering-wheel controls and other integrated vehicle functions.
It is an effective solution for vehicle owners who want improved amplifier power and sound-system performance without replacing the original head unit.
What Is a High-to-Low-Level Converter?
An aftermarket amplifier generally receives its audio signal through low-level RCA inputs. These signals are normally supplied by an aftermarket head unit with dedicated preamp outputs.
Factory radios frequently do not include RCA outputs. Their speaker connections carry a higher-voltage amplified signal that cannot always be connected directly to an amplifier’s RCA inputs.
The HILO V3 reduces this amplified speaker-level signal to an appropriate low-level stereo signal for connection to a compatible amplifier.
It is also commonly described as:
A high-to-low converter
A speaker-level to RCA converter
A line output converter
An OEM amplifier integration converter
These terms describe the same basic function: converting an amplified factory speaker signal into an RCA signal suitable for an aftermarket amplifier.
Two-Channel Stereo RCA Output
The HILO V3 accepts left and right amplified speaker signals and converts them into two low-level RCA outputs.
These stereo RCA connections can provide the signal for a compatible 2-channel or multi-channel amplifier, depending on the design and input-routing capabilities of the amplifier.
The HILO V3 is a two-channel converter. It does not independently convert four, six or eight separate factory audio channels.
Where a system requires front and rear fading, multiple independently processed channels, centre-channel integration or subwoofer-channel summing, additional integration equipment may be required.
An Authorised Focal Australia Dealer can assess the factory system and determine whether one HILO V3 is sufficient for the proposed amplifier installation.
Retain the Original Vehicle Controls
Replacing a modern factory head unit can be difficult or impractical because it may control much more than the vehicle’s audio system.
Depending on the vehicle, the original infotainment system may also manage climate settings, reversing-camera information, vehicle configuration, steering-wheel controls, parking displays and driver-assistance functions.
The HILO V3 allows the original source unit to remain installed while providing an analogue RCA signal for a compatible aftermarket amplifier.
This helps preserve the factory dashboard appearance and original vehicle functions while creating a pathway to improved amplifier and speaker performance.
Built-In Speaker Impedance Simulation
Some modern factory head units monitor the electrical load connected to their speaker outputs.
If the original speaker is disconnected and the head unit no longer detects the expected load, the audio output may mute, produce an error or operate incorrectly.
The HILO V3 includes a speaker simulation network designed to present a suitable load to compatible factory speaker outputs. Its specified input impedance is 36 ohms.
This helps prevent muting or output interruption in factory systems that require a detected speaker load.
The impedance simulator improves compatibility, but it should not be interpreted as a guarantee that the converter will operate with every factory audio architecture. Vehicle-specific testing and compatibility confirmation may still be required.
Selectable DC and AC Signal Detection
The HILO V3 supports selectable DC and AC signal detection for automatic amplifier activation.
Different factory head units use different types of output behaviour when audio is present. Some can be detected through a DC voltage change, while others require detection of the AC audio signal.
The selectable detection system allows the installer to choose the method appropriate for the factory source.
When the HILO V3 detects the relevant signal, it can generate a remote turn-on output for the connected amplifier. This allows the amplifier to switch on and off automatically with the factory audio system.
Correct detection mode and threshold behaviour should be tested during installation to prevent delayed activation, unwanted shutdown or an amplifier remaining powered after the vehicle is turned off.
Automatic Amplifier Remote Turn-On
Many factory radios do not provide a conventional 12-volt amplifier remote wire.
The HILO V3 can automatically generate a remote output when it detects that the compatible factory audio system is active.
This remote signal can be used to switch on the connected aftermarket amplifier without installing a separate manual switch or relying on an unrelated accessory circuit.
Automatic remote turn-on helps create a more integrated installation. The factory system continues to operate normally, and the aftermarket amplifier activates when an appropriate audio or voltage signal is detected.
The remote output requires the HILO V3 to be connected to a suitable 12-volt power supply.
Active or Passive Operation
The HILO V3 can be used in active or passive mode.
In active operation, the converter is supplied with 12-volt power. This enables its automatic signal-detection and amplifier remote-output functions.
The HILO V3 can also convert the speaker-level signal in passive mode without a 12-volt power connection. However, the automatic remote output will not operate in passive mode.
When passive operation is used, the amplifier will require another suitable and correctly switched remote-turn-on source.
The appropriate operating method depends on the vehicle, factory source, amplifier and overall installation design.
Designed to Reduce Noise and Grounding Problems
The HILO V3 provides separated signal grounds to help reduce parasitic interference and grounding-related noise.
Poorly designed high-to-low converters can introduce alternator whine, background noise, buzzing or other interference into an upgraded car audio system.
The HILO V3 has been engineered to provide a clean conversion pathway between compatible amplified speaker outputs and the RCA inputs of an aftermarket amplifier.
Focal specifies a signal-to-noise ratio greater than 100dB and distortion below 0.01%, supporting accurate conversion without adding unnecessary noise or audible colouration.
The final noise performance will also depend on correct power wiring, grounding, RCA routing, amplifier gain adjustment and installation quality.
Wide 10Hz to 80kHz Bandwidth
The HILO V3 has a specified bandwidth of 10Hz to 80kHz within ±1dB.
This wide operating range allows the converter to pass the audio frequencies required for full-range speakers and subwoofer amplification without unnecessarily restricting the signal.
The HILO V3 does not create bass, treble or additional detail that is absent from the factory signal. Its role is to convert the available amplified signal cleanly for use by another amplifier.
Any equalisation, crossover filtering or frequency limitations already applied by the factory audio system may remain present after conversion.
For vehicles with heavily equalised or frequency-limited factory outputs, additional digital signal processing may be required to achieve the desired result.
Compatible with Stop-Start Vehicles
The HILO V3 is designed to be compatible with vehicle stop-start systems.
Modern vehicles may temporarily change their electrical-system voltage when the engine stops and restarts. Audio equipment that is not designed for these fluctuations may switch off, reset or produce unwanted noise.
The HILO V3 has been developed to maintain suitable operation within compatible stop-start vehicle installations.
The amplifier, processor and other connected audio equipment should also be confirmed as suitable for the vehicle’s charging and stop-start system.
Use with Factory Head-Unit or Amplifier Outputs
Depending on the vehicle, the HILO V3 may receive its speaker-level signal directly from the factory head unit or from a suitable amplified output elsewhere in the original system.
The selected connection point must provide an analogue amplified signal within the operating requirements of the converter.
Not every output within a factory-amplified system is suitable. Some vehicles use digitally networked amplifiers, unusual balanced signals, active crossovers or channel-specific processing.
The installer should test the signal before connection and confirm its voltage, frequency range, polarity and behaviour at different volume levels.
Not a Digital Signal Processor
The HILO V3 is a signal converter, not a digital signal processor.
It does not automatically remove factory equalisation, combine multiple frequency-limited channels, restore missing frequencies or provide time alignment.
It also does not independently provide crossovers, parametric equalisation, channel delays or system tuning.
Where the original audio system applies substantial processing, a separate DSP or advanced OEM integration processor may be required after or instead of a conventional line output converter.
The correct integration method depends on the complexity of the vehicle’s factory audio architecture and the objectives of the upgrade.
Not an Amplifier
The HILO V3 does not increase speaker power.
Its purpose is to provide an appropriate RCA signal for a separate aftermarket amplifier.
A complete installation will normally require:
A compatible power amplifier
Correctly sized amplifier power and ground wiring
Suitable fusing
RCA interconnects
Speaker wiring or vehicle-specific harnesses
A secure mounting location
Correct gain and crossover configuration
The HILO V3 should be regarded as an integration component within the complete audio upgrade rather than a standalone performance upgrade.
Suitable for Many Vehicle Brands
The HILO V3 is not restricted to one vehicle manufacturer.
Its selectable detection methods and high-level conversion design allow it to work with a broad range of compatible original head units from different manufacturers.
However, it is not universally compatible with every vehicle or factory audio system.
Vehicles using fibre-optic audio networks, digital-only outputs, unusual high-voltage signals, active multi-channel processing or protected factory amplifiers may require a different integration solution.
Compatibility should be based on the actual audio signal and system architecture rather than the vehicle badge alone.
Compact Installation
The HILO V3 has a compact enclosure measuring approximately 94.25mm by 72mm by 24mm at its maximum dimensions.
Its small size allows it to be installed discreetly behind dashboard trim, near the original head unit or in another protected location where access to the required speaker-level signals is available.
The converter should be mounted securely and kept away from moisture, excessive heat, moving components and sources of electrical interference.
RCA and signal cables should be routed carefully to reduce the risk of noise entering the completed audio system.
Professional Installation Recommended
Although the HILO V3 simplifies factory amplifier integration, correct installation requires a sound understanding of automotive electrical and audio systems.
The installer must identify the correct speaker-level outputs, verify signal polarity and frequency content, select the correct detection mode and provide suitable power and grounding.
The amplifier gain must also be matched correctly to the HILO V3 output. Excessive gain can introduce noise and distortion, while insufficient gain may prevent the amplifier from delivering its intended performance.
Professional installation by an Authorised Focal Australia Dealer is recommended, particularly in vehicles with complex factory audio systems or external amplifiers.
Preserve the Factory Interior
The HILO V3 allows a compatible aftermarket amplifier to be installed without changing the visible factory head unit.
The converter, amplifier and associated wiring can normally be concealed behind trim or within another appropriate installation location.
This allows the vehicle to retain its original dashboard, controls and infotainment appearance while benefiting from improved amplifier power and speaker control.
A carefully designed installation can also remain substantially reversible, provided the original wiring is connected through appropriate harnesses rather than being permanently modified.
Create a Complete Focal Audio Upgrade
The HILO V3 can be used as part of a broader Focal car audio installation.
Once an appropriate RCA signal has been created, a compatible amplifier can provide additional power to Focal component speakers, coaxial speakers or subwoofers.
The final system may include vehicle-specific Focal Inside speakers, universal-fit Focal speaker kits, a multi-channel amplifier, a monoblock subwoofer amplifier or digital signal processing.
The exact configuration should be selected according to the vehicle, original audio system, speaker locations, listening preferences and available installation space.
Correct system design is essential. The converter, amplifier, speakers and electrical installation must all work together to achieve a reliable and well-balanced result.
