One of the most confusing things, when people are trying to install an amplifier, is how to wire high input on amplifier. While there are plenty of different ways, this article will go through a basic installation process for amplifiers with high-level inputs. We have tried to solve this problem with easy steps for a normal person.

The following explanation gives some insight into how to wire high level inputs (speaker connections) on an amplifier. If you are not familiar with this subject it is suggested that you read our article about speaker connections before you continue reading.

What is high level input on amp?

When a speaker wire is wired off the back of your radio instead of from an amplifier, it’s going to drain a lot more power from the car battery due to resistance. The effect will be that you’ll then have less treble and bass as those frequencies sound much lower when they’re coming from the back wires.

How to wire high level input on amplifier? Achieve greater quality audio with high to low converters. The most popular and effective method is the Line Output Converter; it connects radio speaker wires, boosting signals into preamp-level sound that’ll take your listening experience up a notch!


High input amp wiring:

Using only positive(+) wire

High level input (speaker connection) of the amplifiers works like the normal speaker outputs, but instead of having a “negative” and a “positive” wire (connected to the speaker) we use only one (positive) for both (for example speakers and speaker cables) and we connect it to “GND”.

What is meant by GND?

GND is short for “GROUND”, which means that it connects to the negative terminal of the battery.

Normally you would plug in your speaker cable (negative and positive wire) in the speaker terminals (marked as “Speaker”) of the amplifier.

To connect a high level input car amplifier, we would need to cut off or remove those two (positive and negative) wires that are connected to the speakers, which is no problem at all since those wires already existed before you bought your amplifier with speaker connections.

Please pay attention to where to cut the wires, you don’t want to damage the amp when cutting off the wires! Label each wire with some tape or a marker so you know which is which.

Please note that the GND cable is attached to the speaker terminal you want to use, otherwise, it won’t work! And make sure you connect “+” and “-” to the correct terminals or your amplifier will be damaged when powering it up!

Above one of the speakers is “positive” and one speaker is “negative” (the white wire is positive and the black wire is negative, which gives a total difference of 3.3V). This means that both speakers create an equal sound wave, but are opposite in polarity so it cancels each other out.


By connecting both speaker cables (positive and negative) to one terminal (marked as “GND”) we get a big increase in voltage for our speakers, but unfortunately, we lose the loudness canceling effect of it.

By doubling both wires, positive and negative, we will increase the sound pressure level by 6dB. By altering the speaker cables to one wire (positive) and connecting it to GND we are creating a high level input on an amplifier.


So instead of using two wires, one for the speaker positive and the other one for the negative terminal, you can use only one wire which connects both terminals together, let’s say that this is your “high level input” wire.

Please note that there is no polarity on high level inputs, so you can connect the wires to the right “GND” terminal but don’t worry about which cable you connect first or last, it doesn’t make any difference.

This also means that you could even use an unseparated speaker cable (for example a 2-wire cable) to connect your speaker.


The only drawback here is that you cannot switch between stereo and surround modes because all speakers are connected together.

If you have an amplifier with more than two high level inputs you could easily add another car amp with high level input to it and connect those too.

You could also wire one speaker as “positive” and the other as “negative”, but this would damage your amplifier when powering it up! We would recommend you use only one type of speaker (both positive or negative), so you cannot accidentally damage your amplifier by mistake.

Also Read: 11 Best Budget Car Amplifiers


To make this project even more effective you could add a capacitor to the positive-negative wire between the amplifier and speakers. A capacitor would protect your amp from high spikes that occur when music changes, but it’s not required for this circuit to work.

For speakers that are able to handle low frequency information (for example subwoofers) you don’t need a capacitor, but for speakers that struggle with low frequencies, you should always use some kind of filter.

If you want to add a capacitor for your project it is recommended that you buy a “bi-polar” capacitor instead of a normal one because they can also block DC signals and spikes from going through the amplifier which would damage it.

But if you aren’t able to find a bi-polar capacitor you can always use two normal capacitors in “series” which means one after the other instead of one above and below each other, they will work just as fine.

The capacitor will block DC signals and spikes so it won’t damage your amplifier when music changes quickly, but it is not required to make this circuit work.

If you don’t want to add a capacitor you could just use one with an impedance of at least 470uF or higher.


To make this project even safer you could add a voltage regulator between high level input and the amplifier. The only reason to use a voltage regulator is when you want to be 100% sure your amplifier doesn’t get too much power.

For example, if you plan on using some very powerful speakers with it. If your amp can handle high power you don’t need a voltage regulator because it will damage your amplifier when powering it up!

When you add a voltage regulator to this circuit, be sure to use an adjustable regulator so you can adjust the output down. This way you get more control over the sound pressure level output of your speakers and if they are too loud or not.

On this amplifier, we have added a voltage regulator with adjustable output and an impedance of 5V between high level input and amplifier.

Connect all your speakers to the corresponding positive and negative terminal on the high level input.

Because we use a passive filter there is no need to worry about what impedance your speakers are, they can be 8 Ohm, 4 Ohm, or even 2 Ohm.

The only thing you need to make sure of is that you connect all your speakers with the same impedance to your amplifier.

So for example, if you have three 8 Ohm speakers and one 4 Ohm speaker it would be best to wire the negative wire of two 8 Ohm speakers together and both positive wires to the 8 Ohm negative terminal on your amplifier.

Then wire the positive wire of the 4 Ohm speaker alone to its positive terminal.

Also Read: What are the causes that make a car amplifier hot?

If you have two types of speakers with different impedance but are able to handle low frequency signals (for example subwoofers) you could always “combine” them together, meaning connect both positive and negative of both speakers together and then connect them to your amplifier.

This way you could use one subwoofer for the lows and also have a small speaker to play mid-higher frequencies from.

If you do plan on using two types of speakers with different impedance you should always read up on how the volume works when putting them in parallel.

We have three 8 Ohm speakers wired to one terminal on the amplifier and a single 4 Ohm speaker wired to its terminal.

This way we get more volume with less distortion, because of how the passive filter works if we connect two 8 Ohms speakers we would get double the amount of resistance and less control over the frequency response.

When using two types of speakers wire them to one terminal and then connect that correct terminal to the corresponding terminal on the amplifier. If you have four speakers wire all negative terminals together and all positive terminals together.

One 8 Ohm speaker, this speaker has an impedance of 4 Ohms when combined with one 4 Ohm speaker.

One 8 Ohm speaker, this speaker has an impedance of 2 Ohms when combined with two 4 Ohm speakers.

You can see the impedance will always add together when adding speakers in parallel. If we have a total impedance of 16 Ohms and in the last picture a total impedance of 8 Ohms.

Both types of speakers are wired in parallel and then connected to the corresponding terminals on the amplifier.

One 4 Ohm speaker, this speaker has an impedance of 2 Ohms when combined to one 8 Ohm speaker.

When using only one type of speaker there is no need for a voltage regulator between high level input and the amplifier because there will be no chance of overvoltage.

But with a voltage regulator in between high level input and amplifier. You can wire your speakers to their corresponding positive or negative terminals on the amplifier directly. It doesn’t matter which ones you use since they are wired in parallel.

The voltage regulator will only work if you have an adjustable output, otherwise, it’s just a waste of money.

Notes: When wiring the speakers to high level input don’t wire them in parallel because they are all wired to one terminal. You can wire them to their corresponding positive or negative terminals on the amplifier directly without using any voltage regulators.

If you do want to use a voltage regulator because your speakers have different impedance then wire all positive terminals together and negative terminals in parallel.

When wiring multiple speakers in parallel you don’t need any voltage regulators since all of them are wired to one terminal on the amplifier.

However you should always read up on how volume works when putting speakers in parallel if you want to get the most out of them, otherwise, you might get distortion and an unclear sound.

A tip when wiring multiple speakers in parallel is to put them inside a metal frame so it’s easy to mount them to your car or boat.

Also, make sure the frame doesn’t touch any conducting surfaces such as car chassis or ground because this will cause unwanted noise in the speakers.

An alternative to using multiple speakers wired in parallel is to use one speaker with more than double the impedance of each speaker in series, this way when combined they will have an impedance that matches your amplifier.

The only downside with this approach is that you always lose some volume because when putting two speakers in series their resistance adds up, not their power capacity.

If the impedance of the speaker is too high you can wire it in series with multiple 8 Ohm speakers to lower its impedance. The only downside with this approach is that you always lose some volume because when putting two speakers in series their resistance adds up, not their power capacity.

Notes: We have two 4 Ohm speakers wired in series to create an 8 Ohm speaker. When combining the impedance of two speakers using this method always add their resistance together.

When wiring speakers in series you don’t need any special voltage regulators between high level input and the amplifier because there will be no chance of overvoltage.

If your speaker has an impedance that is too high you can wire it in series with multiple 8 Ohm speakers to lower its impedance. The only downside with this approach is that you always lose some volume since when putting two speakers in series their resistance adds up, not their power capacity.


An alternative to using multiple speakers wired in parallel or series is to use a passive crossover filter between high level input and amplifier.

There are a lot of different types of passive crossovers on the market, this way you can adjust each frequency for each speaker separately or together with other speakers.

Note: A crossover filter is basically a resistor and capacitor wired in parallel to each other where one side has low impedance and the other side has high impedance.


Notes: When mounting the board solder only three of the four holes for each capacitor are on top of the board. The hole facing the other capacitor should be empty so it has space for heatsink paste.

If you ever want to change or replace one of the capacitors then just melt that solder joint and push out the existing capacitor with pliers.

Once you’ve mounted your resistors, potentiometer, and input jacks it’s time to mount your capacitors. If you bought a kit from us then there’s already heatsink paste on the back of them which makes it easy to mount with just a bit of solder on top of each one.

Once you’ve soldered all capacitors and potentiometer, place some thermal paste on top of your power element and add the heatsink. This will make sure your amplifier runs as cool as possible and it won’t overheat.

Notes: If you forget to place any thermal paste on top of the power element before adding the heatsink, don’t worry since it’s still very easy to add afterward by using a small screwdriver.

Once all capacitors and potentiometers are mounted we recommend testing the amplifier in-circuit before adding any wires. If you have a multimeter it takes only two minutes to test all four channels and be sure that nothing is broken or faulty.

After verifying that all four channels are working properly we recommend mounting your amplifier into an enclosure. This way your amplifier will stay safe from dust, water, children, and pets.

Note: If you don’t have an enclosure big enough to fit your amplifier, never fear because there are plenty of premade enclosures out there to buy. Just make sure they are not too deep since most amplifiers use a heatsink which needs some room in front of it for proper ventilation.

Also Read: 7 Signs of a bad car amplifier-Guide


The easiest way to power the amplifier is to tap into your car’s cigarette lighter plug since this will give you a constant 12V. You can do it on either side of the plug depending on what you prefer.

Just remember that it’s always best to have a fuse between the power source and amp itself, just in case something fails.

Always use a good quality speaker wire to connect your amplifier. To avoid noise and interference we recommend using at least 16-18 Gauge wire, preferably shorter than three feet.

If you made it this far then congratulations, you now know everything you need to know in order to build your very own high quality car audio amplifier!

Once all capacitors are mounted, solder the input wires to the RCA inputs on top of the board. You can then mount your amplifier into an enclosure or leave it open for DIY projects.

Notes: If you plan on mounting your amplifier without any kind of case then we recommend using hot glue, double sided tape or epoxy resin in order to avoid damaging it.


There are three main steps to install an amplifier with high-level inputs: speaker wire, RCA cables, and remote turn-on wire. Each method has its own benefits and drawbacks. We will explain each method so that you can choose the one that works best for your installation.


The RCA Cable method involves using a device called a line output converter (L.O.C.) to convert high-level signals from the factory radio into low-level signals that can be read by the amplifier.

The RCA output wires from the converter are then connected to the amplifier, while a power wire from the car battery is connected to the L.O.C.’s power supply.

This method allows for the installation of an amplifier with high-level inputs in a location far from the factory radio without having to rewire speakers or run new speaker wires.

By converting speaker signals into pre-amp signals, this method ensures that the amplifier receives a clear and high-quality audio signal.


The Speaker Wire method involves connecting the amplifier directly to the factory stereo using speaker wires. This method usually leaves the speakers intact, although cutting them out may make it easier to run the wires between the amp and the factory stereo.

If you choose to use the Speaker Wire method, make sure there is enough space between the amplifier and the driver’s side firewall (or wherever you choose to mount the amplifier).


The Remote Turn-On Cable includes a small box that sends a 12-volt signal when you turn on your car. It can be plugged into a cigarette lighter or accessory port under your car stereo (if available).

The amp will only turn on when it senses this voltage which means that there won’t be any power drawn from the car battery when the stereo is off. This method is useful if your amp doesn’t have a remote turn-on wire.

Make sure to follow the wiring instructions that come with your products, regardless of the method you choose.


The difference between an amplifier’s high-level input and low-level input is how it takes audio signals.


A “high level” signal is one that has been sent out of the audio device with a high voltage, but very little current.

This can be accomplished by boosting the volume before sending audio to the amp (for instance on your phone) or when using an instrument amplifying system like when you plug into an amp and then into a PA system.


Easy to set up – all you need is a standard RCA cable.
No power required – the amplifier gets its power from the head unit.
Works with any head unit – no special equipment or settings needed.
Can be used with aftermarket or factory head units.
Less likely to cause interference than low-level input.
More reliable signal transmission than low-level input.
Cheaper than low-level input.


  • Only compatible with head units that have preamp outputs or line outs.
  • Signal loss may occur at high volumes compared to low-level input.
  • Uses up one of the head unit’s RCA preamp cables.
  • May need an inline resistor to prevent overloading the amplifier’s inputs.
  • There is a potential for ground loop problems if you run both high and low-level inputs into the same system simultaneously.


A “low level” signal is when you use cables that require lower voltage but higher current in order for them to work properly.

Generally speaking, if you’re powering your speakers directly through your phone, this means tapping into what is called the speaker’s “negative” or “ground” terminal. If you’re using an amplifier.

The negative output found on your amp is what you will plug your speakers into. But why does it matter? Simply put, powering speakers with a low-level signal means they will receive more current than if they were powered by a high-level input.


  • Works with head units that have preamp outputs or line outs and can also work with some factory head units with adapters.
  • Less likely to pick up interference from other components in the car.
  • No need for an additional power source as the amplifier gets its power from the head unit.
  • More stable signal transmission compared to high-level input.
  • Generally less expensive than high-level input.


  • Signal loss may happen at high volumes.
  • Uses up one of your head unit’s RCA preamp cables.
  • Potential ground loop issues if running both high- and low-level inputs together.


An amp with a high-level input connector allows you to easily connect it to your vehicle’s original radio without changing any wiring. This is great for those who want to add an amp to their car without changing the factory wiring.

You just need to connect the power and ground cables from the amp to the corresponding connectors on the back of the radio. Then connect the signal cable from the amp’s output connector to the high-level input on the amp.

When installing an amplifier with a high-level input connector, you should use a good quality RCA cable that is specifically designed for amplifiers. A cheap RCA cable may not be able to handle the increased current flow and could potentially damage your amplifier.


Dual input on a subwoofer gives you an additional way to adjust how sensitive the subwoofer is to the audio signal it receives. Typically, you would use a single signal from your audio processor to power the subwoofer.

However, if your processor has a very low output, you can use a Y-splitter to connect both inputs of the subwoofer with the same signal. This doubles the subwoofer sensitivity, meaning it can pick up more subtle changes in the audio signal and produce a stronger bass output.


Having a good high-level input on your subwoofer is important to get the best sound quality from your speakers and sound system. When you are looking for a new subwoofer, make sure to check the specifications and ensure that it has a sufficient high-level input.

Most modern subwoofers have this type of input, but some older models may only have speaker wire terminals.


With just a few simple steps, you can enhance your home theater setup! Connect the single connector to your AV receiver’s subwoofer pre-out and then use two extensions for each of the subwoofer inputs. Once this is done, get ready for surround sound bliss as you configure your system like usual!


Connect a wire from the back of the radio to the input wire coming off of your subwoofer.

This will let you hear what’s playing through your speaker system instead of picking up static from distance sources. If you’re listening to a signal source that doesn’t have volume control.

Then connect the volume-controlled output on your computer or CD player to an amplifier and connect another wire from that amplifier into your automobile’s stereo system.

Now you can adjust the volume at whatever level is comfortable for you which can be especially nice if other passengers in cars with multiple speakers prefer their music at different levels.


A subwoofer usually has only one Phono RCA connector for sub-outputs because the

audio signal is mono, which is also known as the LFE channel. This channel is a part of a 5.1

or 7.1 surround sound setup and is represented by the “X.1” naming convention.

If a surround receiver has multiple subwoofer outputs, they are also in mono. It is possible to connect multiple subwoofers to these outputs.


Here are the basic steps to tune a car audio system that includes a subwoofer amp:

  • Turn down the subwoofer amp gain, turn up the low-pass filter, and turn off the bass boost.
  • Turn on the head unit and set all tone controls to the middle settings.


According to professionals, the ideal range of frequency in Hz for bass is between 60-250 Hz. This range helps to protect your speakers from damage and ensures a safe and optimal listening experience for you. Listening to bass at frequencies lower than this range can harm your hearing.


When setting up a subwoofer system, it is important to perform testing to ensure that everything is functioning properly and producing the desired sound quality. One way to test if the subwoofers are producing sound is to play music that has a lot of bass. This will allow you to hear if the subwoofers are working correctly.

Additionally, it is important to check for any loose connections or wiring mistakes that may be impacting the performance of the system. Inspect all the connections between the subwoofers, amplifier, and head unit to ensure that everything is properly connected. If you notice any issues, fix them before making adjustments to the amplifier settings.

Once you are sure everything is properly connected, you can make adjustments to the amplifier settings to achieve the desired sound quality. This may involve adjusting the gain, low-pass filter, or bass boost, among other settings.

By following these steps, you can ensure that your subwoofer system is working correctly and producing the optimal sound quality.


There are various methods for connecting an amplifier, but we will concentrate on the high-input amplifier wiring diagram. This wiring technique is widely used in vehicles as it permits the utilization of the existing stereo signal to operate the new amplifier.


Take the ground wire from your amplifier and attach it to a suitable ground point in your car. The most optimal place to do this is typically your car’s battery.


To begin, you must discover which wires in your car’s stereo harness transmit audio signals. These wires are typically red and white, but they can vary depending on the type of car you have. After identifying the audio signal wires, connect them to the corresponding inputs on your amplifier.


Attach the power wire from your amplifier to a fused ignition-switched power source in your car. If you’re unsure where it’s located, refer to your owner’s manual.

Next, run another ground wire from the same point and connect both ground wires to the car’s body using self-tapping screws. This will prevent electrical noise from affecting your audio equipment, resulting in a cleaner and clearer sound quality.


The five pins in the high-level input connector are:

  • Power
  • Ground signal input
  • Enable input
  • Feedback output

Connect the power and ground pins to your car’s battery and ground, respectively. The signal input wire will receive signals from your sensors, and the enable input wire is utilized to manage whether the sensor signals are being read by the ECU.

The feedback output wire sends information back to the ECU about how much voltage was applied to the signal input. This information can be utilized to determine various things, such as pedal or throttle position.


1. Is it better to use high level inputs on car AMP?

Amplifiers have come a long way, now allowing you to connect speaker wires directly and easily. This upgrade in installation guarantees superior sound quality with inputs up to 10 volts!

2. How do you connect a high level speaker input?

Connect your high level signal to the speaker wire inputs on the amplifier and connect the positive and negative wires from your subwoofer to it. Make sure that these connections are soldered securely since they will be exposed to some vibration over time.

3. What is high level output on AMP?

High level output on car amplifier is a function that sends an amplified signal to another amplifier, equalizers and processors. It’s similar to high level inputs but not the same thing and will usually require some kind of line driver or signal processor before it can be used.

4. What does preamp out mean?

Preamp out on an amp is a direct connection to the speaker wire inputs of another amplifier without any form of signal processing. It’s usually controlled by a switch so that only one amplifier is active at a time preventing noise and signal interference.

5. How much power can your car cigarette lighter supply?

Most 12V car cigarettes will provide around 10 Amps of current which is more than enough to supply a decent sized amplifier. Make sure that you don’t exceed the limit because this will cause your power source to fail and damage could occur if you try to force more current through it.

6. Is it better to use a mono or 2 channel car amp?

The short answer is both because mono amps are usually smaller and have lower cost but 2 channel amps are more versatile because they can be used for subwoofers, speakers, and other equipment that requires stereo signal.

7. What is high level input on car subwoofer?

By connecting your subwoofers to the same terminals as your left and right speakers, you can guarantee that they are perfectly in sync with one another. This ensures that no matter what music or movie soundtrack is being played, it will sound harmonious – achieving optimal audio performance!

8. What is low pass car amp?

Low pass car amps are used for bass frequencies and filter them to speakers and subwoofers. It’s usually mounted near the front of the car and allows you to adjust the bass or filtering frequency depending on what kind of equipment you’re using.

Related Article: 12 Best Car Amplifier For Bass

9. What is a high level signal?

A high level signal is an unamplified pre-amp output from your head unit that will provide a preamp connection. It’s something that you can connect to with speakers or amplifiers but it will need an amplifier to power them in order for them to work.

10. What is a high pass car amp?

High pass amps are used for mid and high frequencies and send these signals directly to your speakers or subwoofers without filtering the bass. It’s usually mounted near the front of your vehicle and has a switch that allows you to turn it on or off as needed.

11. What is high pass filter?

A high pass filter is an electronic device used for filtering out any frequency below a set point so that only higher frequencies are allowed through. These are usually installed downstream from an amplifier to prevent the subwoofers from being overdriven.

12. What is a low pass car amp?

This is used for high frequencies and sends them directly to your speakers or subwoofers where they are filtered so that only medium to higher frequencies are allowed through. It’s usually mounted near the front of your vehicle and has a switch that allows you to turn it on or off depending on your system.

13. What is high level input on subwoofer?

The high-level input on a subwoofer provides an easy way to connect it to your existing stereo or home theatre’s speaker outputs.

There are several advantages of using the high level connections such as: less loss, more dynamic sound and better control than RCA connections.

14. what is 4 channel amp high level input?

Answer: A 4 channel amp is a stereo amplifier with two more channels built in to boost SPL. The 2 added channels require their own power and signal cable, and they both amplify the same signal that’s running through your amp.

15. Are high-level inputs better than RCAs?

For the best possible sound performance, using balanced differential inputs on your power amp offers significant improvements, particularly in noise cancellation, over traditional single-ended RCA signals.

16. How do high and low inputs on an amplifier differ?

To prevent signal distortion and loss, guitarists and bass players need to select the appropriate input setting. The “Hi” option will attenuate their sound by up to 15dB while its counterpart, “Low”, offers a preferred alternative for instruments that already produce lower volume levels.


If you take an amplifier and connect it directly to a battery, you’ll get too much power. If you want to try how to wire high level input on car amplifier, You must use one of these, capacitors, voltage regulators, a car’s cigarette lighter plug, or a crossover filter.

I have also used a high pass capacitor, but if you don’t know about it then consult a car audio electronics professional.

Thank you for reading! I hope this article will help you to resolve your problem. To encourage my study passion, please share this article with your friends for their beneficial knowledge. This will save their time for consultancy and money for saving.

👉 Common Installation Mistakes to Avoid When Installing a Car Amplifier