Metra Line Output Converter Wiring Diagram PDF: A Comprehensive Guide
Embark on a journey to amplify your audio experience! This detailed guide unlocks the secrets within your Metra LOC, providing essential wiring diagrams and installation insights.
Understanding Line Output Converters (LOCs)
Line Output Converters, or LOCs, are crucial components when integrating aftermarket audio systems with factory car stereos. Many factory head units lack the RCA outputs needed for connecting to amplifiers, relying instead on speaker-level outputs. LOCs bridge this gap, converting high-level speaker signals into low-level RCA signals that amplifiers can readily process.
Essentially, an LOC steps down the voltage and impedance of the signal, ensuring compatibility and optimal performance. Without an LOC, directly connecting an amplifier to speaker wires can result in distorted audio, damage to the amplifier, or poor sound quality. They are vital for maintaining signal integrity and achieving a clean, powerful audio output. Understanding this conversion process is key to successful car audio installation.
What is a Metra LOC and Why Use One?
Metra is a renowned name in car audio accessories, and their Line Output Converters (LOCs) are designed to seamlessly integrate aftermarket audio equipment with factory sound systems. A Metra LOC specifically takes the speaker-level outputs from your vehicle’s existing stereo and transforms them into the RCA outputs required by most amplifiers.
Why choose a Metra LOC? They offer a reliable solution for upgrading your car audio without replacing the factory head unit, preserving features like steering wheel controls and factory displays. Utilizing a Metra LOC ensures proper impedance matching, preventing signal distortion and potential damage to your amplifier. It’s a cost-effective way to significantly enhance your in-car audio experience.
Types of Metra Line Output Converters
Metra offers a diverse range of LOCs to cater to various audio system configurations. Single Channel LOCs are ideal for adding a subwoofer to a system, providing a dedicated signal for low-frequency reproduction. Dual Channel LOCs are commonly used for front or rear speaker setups, delivering a stereo signal to an amplifier.
For more complex systems, Four Channel LOCs provide independent signal conversion for front and rear speakers, enabling precise control over each channel. Some advanced Metra LOCs also include features like remote turn-on detection and adjustable gain controls. Choosing the right LOC depends on the number of channels your amplifier supports and the desired level of customization.
Single Channel LOCs
Metra’s single channel Line Output Converters are specifically designed for subwoofer applications, converting a single high-level speaker signal into a low-level RCA output. These LOCs are perfect for systems where you want to add a dedicated subwoofer without replacing the factory head unit. They typically feature a straightforward wiring configuration, focusing on receiving the rear speaker output and sending a summed mono signal to the amplifier.
Key features often include adjustable gain controls to match the LOC’s output to the amplifier’s input sensitivity. Proper gain staging is crucial for optimal subwoofer performance. Single channel LOCs are a cost-effective solution for enhancing bass response in your vehicle’s audio system.
Dual Channel LOCs
Metra’s dual channel Line Output Converters are ideal for systems requiring stereo output, typically used when adding an amplifier to power front speakers or a front/rear speaker setup. These LOCs accept a pair of high-level speaker inputs, converting them into two RCA outputs, preserving the stereo separation. They’re a versatile option for upgrading audio without replacing the factory head unit.
Dual channel LOCs often include features like adjustable gain controls for each channel, allowing for precise signal matching to the amplifier. Some models also offer selectable input summing, enabling mono output if desired. They provide a balanced approach for enhancing audio quality and power in a stereo configuration.
Four Channel LOCs
Metra’s four channel Line Output Converters are designed for more complex audio systems, supporting full-range audio and subwoofer amplification. These LOCs accept up to four high-level speaker inputs, converting them into four RCA outputs, enabling independent control over each channel. They’re perfect for systems aiming for a truly immersive sound experience.
Four channel LOCs frequently feature independent gain adjustments for each channel, allowing for precise tuning and signal matching to multiple amplifiers. Advanced models may include built-in crossover networks, enabling direct subwoofer control without a separate crossover unit. They offer maximum flexibility and control for building a high-performance audio system.
Installation Overview
Proper installation is key to unlocking optimal performance from your Metra LOC! This section details the necessary tools and crucial safety steps for a seamless setup.
Tools Required for Installation
Successfully installing your Metra Line Output Converter (LOC) demands having the right tools readily available. A standard Phillips head screwdriver is essential for securing the LOC and making connections. Wire strippers are crucial for carefully exposing the conductor within the wires, ensuring clean and reliable connections. You’ll also need crimp connectors or a soldering iron with solder for joining wires effectively.
Don’t forget electrical tape to insulate exposed wires and prevent shorts. A multimeter is incredibly useful for verifying voltage and continuity, aiding in troubleshooting. A wire harness adapter, specific to your vehicle, simplifies connecting to the factory wiring. Pliers can assist with manipulating wires, and zip ties are perfect for neat cable management. Finally, a test tone generator and an audio probe can help fine-tune the LOC’s settings for optimal sound quality.
Safety Precautions Before Installation
Prioritizing safety is paramount when installing a Metra Line Output Converter (LOC). Always disconnect the vehicle’s negative battery terminal before beginning any wiring work to prevent accidental shorts and electrical shock; Work in a well-lit and dry environment to minimize risks. Be extremely cautious when working around the factory wiring harness, avoiding damage to existing wires.
Ensure you understand the wiring diagram thoroughly before making any connections. If you are uncomfortable with automotive electrical work, seek professional installation. Never work on the electrical system while the vehicle is running. Use appropriate safety glasses to protect your eyes from debris. Properly insulate all exposed wires with electrical tape or heat shrink tubing. Double-check all connections before reconnecting the battery.
Wiring Diagrams & Connections
Explore detailed schematics for seamless integration! We’ll dissect Metra LOC connections, offering clear visuals for models 770, 790, and 71-1700, ensuring accurate wiring.
Metra 770 LOC Wiring Diagram
The Metra 770 Line Output Converter is a popular choice for adding an aftermarket amplifier to a factory stereo system. Its wiring diagram typically involves connecting the LOC to the rear speaker outputs of the factory head unit. These connections are usually labeled as Left Rear (+/-) and Right Rear (+/-).
Crucially, ensure correct polarity when connecting these speaker wires; incorrect wiring can result in phase cancellation and poor audio performance. The 770 also requires a 12V remote turn-on lead, typically sourced from the aftermarket head unit, to activate the LOC when the stereo is powered on.
A solid ground connection is paramount for optimal performance and noise reduction. Connect the LOC’s ground wire to a clean, unpainted metal chassis point on the vehicle. Finally, the RCA outputs from the 770 connect to the inputs on your amplifier, transmitting the converted audio signal. Always consult the official Metra 770 manual for the most accurate and up-to-date wiring information.
Metra 790 LOC Wiring Diagram
The Metra 790 Line Output Converter distinguishes itself with its ability to handle higher power levels and often includes additional features like a remote bass knob. Its wiring diagram shares similarities with the 770, utilizing connections to the rear speaker outputs (Left Rear +/- and Right Rear +/-) of the factory head unit.
However, the 790 may also offer connections for front speaker outputs, allowing for a full-range signal conversion. Proper polarity is, again, essential for optimal sound quality. A 12V remote turn-on wire is still required, and a robust ground connection to the vehicle’s chassis is critical for minimizing noise.
RCA outputs transmit the signal to the amplifier. The 790 often includes selectable gain levels, adjustable via dip switches, to match the output of the factory head unit. Refer to the official Metra 790 manual for precise wiring configurations and feature details.
Metra 71-1700 LOC Wiring Diagram
The Metra 71-1700 is a high-input LOC designed for vehicles with complex factory audio systems, often featuring optical or digital signal processing. Its wiring diagram differs significantly from simpler models, requiring specific adapter harnesses to interface with the vehicle’s audio network.
Typically, it connects to the factory amplifier’s output or the main speaker wires, depending on the vehicle’s architecture. This LOC often requires a data connection to detect when the head unit is on, triggering the converter. A dedicated ground wire is crucial for noise reduction.
RCA outputs deliver the converted signal to the aftermarket amplifier. The 71-1700 usually features adjustable gain controls and may include bass restoration circuitry. Always consult the vehicle-specific application guide and the Metra 71-1700 manual for accurate wiring instructions.
General Wiring Principles for Metra LOCs
Regardless of the specific Metra LOC model, several wiring principles remain consistent. Begin by identifying the factory speaker wires – use a wiring diagram specific to your vehicle. Connect the LOC’s input wires to these speaker outputs, matching polarity (positive to positive, negative to negative) for optimal sound quality.
A stable 12V power source, ideally switched with the ignition, is essential for the LOC’s operation. Always use a fuse to protect the circuit. Proper grounding is paramount; connect the LOC’s ground wire to a clean, unpainted metal chassis point, minimizing interference.
RCA cables transmit the converted signal to your amplifier. Shielded cables are recommended to reduce noise. Finally, adjust the gain settings on both the LOC and amplifier to achieve a balanced and distortion-free audio output.
Connecting to Factory Head Unit
When integrating a Metra LOC with a factory head unit, accessing speaker wires is crucial. Typically, these wires are found within the vehicle’s wiring harness behind the radio. A vehicle-specific wiring diagram is indispensable for accurate identification – avoid guesswork!
Utilize a wiring harness adapter whenever possible; this simplifies connections and prevents cutting factory wires. Connect the LOC’s input wires to the corresponding front and rear speaker outputs, ensuring correct polarity. Some factory systems may require a special adapter to properly trigger the LOC’s remote turn-on feature.
Remember that factory head units often have limited output voltage. The LOC boosts this signal, but proper gain staging is vital to prevent distortion and protect your amplifier.
Connecting to Aftermarket Head Unit
Integrating a Metra LOC with an aftermarket head unit is generally straightforward. Most aftermarket units feature dedicated RCA outputs for front, rear, and subwoofer channels. Connect the LOC’s input wires directly to these RCA outputs, matching the channel assignments carefully.
If your head unit lacks sufficient RCA outputs, you can utilize the speaker wire outputs. However, using RCA outputs is preferred for a cleaner signal. Ensure the LOC’s remote turn-on wire is connected to the head unit’s remote output (often labeled “Remote” or “Illumination”).
Proper gain staging remains essential, even with an aftermarket head unit. Adjust the LOC’s gain to match the head unit’s output level, avoiding clipping and distortion.
Grounding the LOC
Establishing a solid ground connection is paramount for optimal performance and to prevent unwanted noise. Connect the LOC’s ground wire to a clean, unpainted metal surface on the vehicle’s chassis, as close to the LOC as possible.
Avoid grounding to components that move or are subject to vibration, as this can loosen the connection over time. A star grounding scheme, where multiple ground wires converge at a single point, can further minimize noise.
Ensure the ground connection is secure and free of corrosion. A poor ground can introduce hum, static, or even complete signal loss. Double-check the connection after installation and periodically inspect it for integrity.
Troubleshooting Common Issues
Diagnose audio problems swiftly! This section provides solutions for no output, distortion, humming, and power issues with your Metra line output converter.
No Output Signal
Encountering silence where sound should be? A lack of output signal is a common frustration. First, verify all wiring connections, meticulously checking the Metra LOC wiring diagram for accuracy. Ensure the factory head unit is powered on and outputting a signal – test with original speakers if possible. Confirm the LOC’s power and ground connections are secure and properly connected to the vehicle’s chassis.
Inspect the fuse within the LOC itself; a blown fuse will immediately halt signal transmission. Double-check the remote turn-on wire connection, as this activates the LOC. If using an aftermarket head unit, confirm the RCA outputs are functioning correctly. Lastly, test the LOC with an alternate audio source to isolate whether the issue lies within the converter or the head unit.
Distorted Audio
Experiencing crackling, clipping, or generally unpleasant sound? Distorted audio often points to gain settings that are too high. Carefully adjust the gain knobs on your Metra LOC, starting with the lowest setting and gradually increasing until a clear signal is achieved. Overdriving the LOC’s input can cause significant distortion. Verify that the input signal from your head unit isn’t already clipping before it reaches the LOC.
Inspect the RCA cables for damage or poor connections; faulty cables can introduce noise and distortion. Ensure proper grounding to minimize interference. Consider the quality of your audio source – a low-bitrate file can sound distorted even with a properly configured LOC. Refer to the Metra LOC wiring diagram to confirm correct input and output connections.
Humming or Static Noise
Annoying humming or static often indicates a grounding issue. Double-check your LOC’s ground connection, ensuring it’s securely fastened to a clean, unpainted metal surface on the vehicle’s chassis. Avoid grounding to plastic or components that aren’t directly connected to the frame. Inspect all RCA cables for damage and ensure they are routed away from power wires to minimize interference.
Verify that the head unit’s ground is also secure. Consider using a noise filter on the power wire leading to the LOC. Consult the Metra LOC wiring diagram to confirm correct connections and identify potential sources of interference. Sometimes, alternator whine can mimic static; a capacitor on the power line might help mitigate this.
LOC Not Turning On
If your Metra LOC isn’t powering on, begin by verifying the power and ground connections. Ensure the power wire is correctly connected to a switched 12V source – one that activates with the ignition. Confirm the ground wire is securely attached to a clean, unpainted metal chassis point. Check the fuse associated with the LOC’s power wire; a blown fuse is a common culprit.
Utilize a multimeter to test voltage at the LOC’s power input to confirm it’s receiving power. Review the Metra LOC wiring diagram to double-check the polarity of the connections. Sometimes, a faulty remote turn-on lead can prevent activation; test its functionality independently. Consider a direct connection to constant 12V for testing purposes (if the LOC supports it).
Advanced Configuration & Settings
Unlock the full potential of your Metra LOC! Fine-tune gain, bass restoration, and crossover networks for optimized audio, tailoring sound to your preferences.
Gain Adjustment on Metra LOCs
Precisely adjusting the gain on your Metra Line Output Converter (LOC) is crucial for achieving optimal audio performance. The gain control matches the LOC’s output level to your amplifier’s input sensitivity. Incorrect gain settings can lead to distortion or a weak signal.
Start with the gain control at its lowest setting. Gradually increase the gain while playing music at a typical listening volume. Use a digital multimeter (DMM) to measure the AC voltage at the amplifier’s input. Aim for a voltage within the amplifier’s specified input sensitivity range – typically between 0.2V and 2V.
Avoid clipping, which occurs when the signal is too strong and distorts the audio. If you notice distortion, immediately reduce the gain. Remember, higher gain doesn’t always equate to better sound; it’s about finding the sweet spot for a clean, powerful signal. Consult your amplifier’s manual for specific input sensitivity recommendations.
Bass Restoration Settings
Many Metra LOCs feature a bass restoration circuit designed to compensate for the low-frequency roll-off often present in factory audio systems. Factory systems frequently lack the robust bass response desired by audiophiles, and this feature aims to address that.
The bass restoration control typically offers adjustable levels, often ranging from 0 to +12dB. Experiment with different settings while listening to bass-heavy music. Start with a moderate boost (e.g., +6dB) and gradually increase or decrease it until you achieve the desired level of bass without introducing distortion.
Be cautious with excessive boosting, as it can strain your amplifier and speakers. Listen carefully for any signs of clipping or muddiness. The ideal setting will depend on your vehicle’s acoustics, speaker quality, and personal preferences. Fine-tuning this setting is key to a satisfying low-end experience.
Crossover Network Configuration
Advanced Metra LOCs often incorporate a built-in crossover network, allowing you to direct specific frequency ranges to your speakers. This feature enhances sound clarity and optimizes speaker performance by preventing them from reproducing frequencies they aren’t designed for.
Typically, you’ll find controls for both high-pass and low-pass filters. The high-pass filter blocks low frequencies from reaching smaller speakers (like tweeters), protecting them from damage and improving mid-range clarity. The low-pass filter directs low frequencies to subwoofers.
Adjust the crossover points based on your speaker specifications and desired sound signature. Consult your speaker manuals for recommended crossover frequencies. Careful configuration ensures a balanced and accurate audio reproduction, maximizing the potential of your entire sound system. Experimentation is key!
Resources & Support
Unlock further assistance with downloadable PDFs, direct Metra support contacts, vibrant online forums, and frequently asked questions for seamless integration.
Downloading Metra LOC Wiring Diagrams (PDF)
Accessing the correct wiring diagram is crucial for a successful installation. Metra offers a comprehensive library of PDF wiring diagrams directly on their official website. These diagrams are specifically tailored to each LOC model – 770, 790, 71-1700, and others – ensuring accuracy and preventing compatibility issues.
To locate your specific diagram, navigate to the “Support” or “Resources” section of Metra’s website and utilize the search function, entering your LOC’s model number. Alternatively, many authorized Metra retailers also provide downloadable PDFs on their product pages.
Ensure you download the diagram corresponding to your exact Metra LOC model. Having the correct PDF will streamline the wiring process, minimizing errors and maximizing audio performance. Always verify the diagram’s revision date to ensure you have the most up-to-date information available.
Metra Customer Support Contact Information
Need personalized assistance with your Metra Line Output Converter wiring or have questions about a specific diagram? Metra provides multiple avenues for customer support. You can reach their dedicated support team via phone during business hours – typically Monday through Friday – at 1-800-827-2900.
For technical inquiries or to submit a support ticket, visit the “Contact Us” page on the official Metra website (metraonline.com). This allows for detailed issue reporting and often faster resolution times.
Additionally, Metra maintains an active presence on social media platforms, offering quick responses to common questions and directing users to relevant resources. Before contacting support, consider checking their online FAQ section, which addresses many frequently encountered issues related to LOC installation and wiring.
Online Forums and Communities for Metra Products
Beyond official support, a wealth of knowledge resides within online communities dedicated to car audio and Metra products. Forums like CarAudio.com and DIYMobileAudio.com host active threads discussing Metra LOC wiring, troubleshooting, and optimal configurations. These platforms allow you to connect with experienced installers and fellow enthusiasts.
Reddit’s r/CarAudio is another valuable resource, offering a diverse range of perspectives and solutions. Searching these forums for “Metra LOC wiring diagram” or specific model numbers (e.g., “Metra 770 wiring”) will yield relevant discussions and potentially pre-existing solutions to your challenges.
Remember to verify information found in forums with official Metra documentation, but these communities can provide invaluable real-world insights and alternative approaches to installation.
Frequently Asked Questions (FAQs) about Metra LOCs
Q: Where can I find a specific Metra LOC wiring diagram PDF? A: Visit Metra’s official website and navigate to the “Support” or “Resources” section. Search by model number (e.g., 770, 790, 71-1700) to download the corresponding PDF.
Q: Can I use a Metra LOC with any aftermarket head unit? A: Generally, yes, but ensure the LOC’s input impedance matches your head unit’s output impedance for optimal signal transfer.
Q: What does the remote turn-on wire do? A: It signals the LOC to power on when the head unit is activated. Proper connection is crucial for functionality.
Q: Why am I getting noise from my LOC? A: Check grounding connections and ensure proper shielding of RCA cables. A faulty ground is a common cause.