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Why Do Pioneer Car Stereos Have 3 Pre-Outs?

Pioneer car stereos are the most popular car stereos in the industry but have you ever wondered why pioneer stereos have 3 pre-outs at the back?

The 3 pre-outs on Pioneer stereos allow you to connect a series of extra speakers, amps, or subwoofers. This lets you connect the advanced sound system of your car without any interference.

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Tip: One thing to note while selecting pioneer models is that the higher the output voltage from preamp outs, the greater the noise resistance and the clearer the sound output. 

From the single din Pioneer stereos with 3 pre-outs, my favorite is the Pioneer DEH-X8800BHS. In addition to the advanced connectivity, it offers HD radio, Bluetooth, MIXTRAX, SiriusXM, and much more. 

In this article, I will dig deep into pre-outs, why you need them, and how to use them to make a good sound system.

What Does Pre-Out on a Receiver Mean?

Audiophiles have been doing modifications to their cars, and manufacturers are becoming more involved in providing features that will satisfy the needs of their customers.

One important feature to make a unique car audio system is the number of pre-outs in the car radio.

Preamp outputs are present at the rear of the Pioneer stereo, and you can use a standard RCA patch cable if you want to add an external amplifier. 

Some of the receivers have 2 pre-outs to add a four-channel amp, while others have three sets, and one of them is used to connect the subwoofer amp.

As you can see, the word pre-out is self-explanatory, meaning “before the output.” This is because the signal from the stereo is first processed by internal crossovers and then sent to different RCA outputs. These outputs are then connected to external amplifiers to drive different types of speakers. 

Pioneer stereos like Pioneer DMH-1500NEX have small built-in amplifiers to power factory speakers. But Car Audio enthusiasts will continue to add external amplifiers to increase the power available to external hungry speakers.

More power means that you can increase the volume without distortion. 

An amplifier boosts up the low-powered signal from the stereo so that it is able to move the speaker coil springs.

But before the sound signal is amplified, it has to be processed by the preamp. 

In a complex sound system, there is more than one preamp. The preamp inside the head unit takes the signal from various sources like a CD player, USB, or radio tuner and sends this low-level signal to the external amp.

At this preamp stage, the sound controls like bass, equalization, and treble make further adjustments to the sound signal. 

Part of the pre-out stage also involves crossovers. Think of crossovers like a traffic cop dividing the traffic depending upon the type of vehicle.

In short, crossovers separate different frequencies and redirect them to different pre-outs. 

Depending on the type of mode you set up, either in-network or standard mode, you can connect the system differently:

  • different audio drivers in front, rear, sub in standard mode, or

Why Would You Need Pre-outs in Car Radio?

Car receivers are complicated devices, and to utilize them properly, you need to know their main features.

One such feature of receivers is pre-outs, and many people are confused about why they need them. 

There are several reasons why you need pre-outs.

  • The first is that pre-outs are used to connect external amplifiers. The external amplifier bypasses the load from the stereo’s internal amplifier and helps meet the power requirements of powerful speakers.
  • Secondly, pre-outs are commonly used to connect subwoofers.
  • Apart from this, it also increases the performance of amplifiers at higher pre-out voltage, and you can lower the gain of the amp, which leads to noise reduction.

Most pioneer stereos have 2 volts, 4 volts, or even 8 volts preamp outputs. The higher the RMS output of pre-out is the better is the sound quality. 

Let’s find why you need high voltage pre-outs. 

When installing a stereo amplifier in our car, you must adjust its gain. To do this, you need to match the output voltage limit of the head unit with the maximum power output of the amp.

It may sound simple, but you have to consider the following things:

  • Does the receiver output distort at full volume?
  • Has anyone adjusted the radio equalizer?
  • Are there any tone controls on the amplifier?

If any of the things are overlooked, the amplifier will not be able to perform at its full capacity.

  • If sensitivity or gain is set too low, then the speakers will not be able to utilize full power from the amp.
  • If the gain is set too high, then the amplifier will produce noise in the form of hiss in the background. So, properly setting up the amplifier is mandatory.

There is a common belief that more voltage equals more volume. So, if you replace the 2-volt pre-out with 4 volts and lower the gain to adjust the increase in voltage, the maximum volume in both cases stays the same.

However, in the second case, in which you are using 4 volts, the gain is low, which means you do not experience distortion at a higher volume. 

As you can see, more voltage does not necessarily make the system louder, but you can reduce gain and hence reduce the potential noise. 

What Are Pros of Using Pre Out?

When you upgrade your sound system, you want its output to be clean and louder.

To achieve this goal, you have to connect amplifiers externally to your stereo via pre-outs. 

Here are some of the benefits of using pre-outs:

Less Overloaded Stereo

The receiver’s built-in amplifiers cannot support a heavy sound system. 

With pre-outs, you can attach external amplifiers that provide power to sound drivers and bypass internal amps, so there is less strain on your stereo.

While choosing a stereo for an advanced car audio system, I recommend you should invest in models like Pioneer DMH-W4660NEX that can operate at higher voltages without pushing their limits. 

Flexible Sound System

You can connect a tweeter, midrange, and subwoofer in network mode in Pioneer stereos.

In standard mode on the other hand, the pre-outs can be connected to the front, rear, and sub-channels.

In both these modes, you can improve your sound system by adding multiple sound drivers. 

Improve Sonic Character

Both active speakers that have their own amplifier and also passive speakers that use external amps can be connected to pre-outs.

This improves the overall sonic character of the stereo.

However, you do not need pre-outs if you install a basic sound system, but you need to know how the system works when dealing with expensive and more advanced setups. 

More Control Over Volume

The line out signal is a constant signal, which means if per channel output of stereo is 4 volts, then the line out voltage output is fixed at most times and has no effect over volume.

However, if you are using pre-outs, the signal is variable, and volume is adjusted according to the stereo output voltage while amplifier gain remains constant. 

Noise Reduction

Preamp outs also lead to noise reduction because you can operate amplifiers at full capacity without adjusting the gain too much. 

What Are Cons of Using Pre Outs?

As everything has its pros and cons, the same is with pre-out. As they enhance the sound quality of your car, but they have drawbacks too. 

Pre Outs Are More Costly

The first disadvantage when it comes to pre-out stereos is that they are expensive as compared to a standard stereo.

If you want to install a high-end stereo system in your car, then a stereo with pre-outs is necessary.

On the other hand, if you require only a basic sound system, then there is no point in buying this type of stereo. 

Higher Power Consumption

Another thing to consider while selecting pioneer stereos with pre-outs is power consumption.

As you can see, these stereos need more power to operate when compared to typical stereos.

Moreover, you install external amplifiers for each channel, which eventually draw its power from the stereo.

If your car battery is of low rating, I recommend installing a separate battery for your car sound system.

Increase Complexity of System

When you are using most of the pre-outs of the stereo, then there are plenty of cables connected to it which increases the complexity of the system.

If the wiring is not done professionally, it can create a mess in your car. So, it is important to keep the cables organized and safe. 

Troubleshooting Becomes Difficult

As the complexity of the sound system increases, it becomes difficult to troubleshoot a problem.

It is possible that when you are using multiple amps, minor inconsistencies may occur and sometimes are not noticed by anybody. 

However for an autophile, these sonic disturbances are noticeable and can create trouble. 

How Do I Use the Pre-Out on My A/V Receiver?

Connecting speakers on your A/V receiver is a simple process. Here is the step you need to follow to use pre-outs on your receiver.

  • First, you have to select whether you are using an in-built amp or an external amp to connect speakers.
  • If you are using external amplifiers, match the corresponding pre-outs on the stereo. For example, if you connect a subwoofer to pre-out, you have different connecting options. You can use a single tip RCA cable, or if there are multiple sub-pre-outs, you can use a Y splitter and an RCA cable. Some stereo models offered dedicated pre-outs for subwoofers.
  • Now plug in other speakers and amps. Play the sound, and if there is some problem, double-check the connections.

What Are the Best Pioneer Head Units With 3 Pre-Outs?

Pioneer head units are one of the best options in terms of quality, performance, and size/weight ratio, among other things.

With 3 pre-outs on its back panel, it can drive front, rear speakers and subwoofers without sacrificing sound quality. 

Below I show you my favorite Pioneer head units with 3 pre-outs:

Pioneer DEH-S6220BS – Single DIN CD Receiver

With touch screen stereos, you can enjoy features like smartphone access, navigation and have more precise music control.

But thanks to the Pioneer DEH-S6220BS where you can use the Pioneer Smart Sync app, you can take advantage of these features in a single din stereo.

If you need directions, then press a button, and this stereo links to navigation apps like Google maps of your mobile device.

Some other features of this stereo include:

  • Built-in Bluetooth for audio streaming and hands-free calling.
  • AM / FM Tuner.
  • USB port for connectivity and charging your devices.
  • Compatible with Pandora and Spotify.
  • 7 preset tone settings with 13 band equalizers.
  • 4 channel X 50 RMS volts, 4 channel amplifier.
  • 6 channel pre-outs for the front, rear, and subwoofer.

Pioneer DEH-S6220BS CD Receiver

Pioneer DMH-C5500NEX – Double DIN Stereo

If you are looking to replace your double din factory stereo, then Pioneer DMH-C5500NEX is a perfect fit for you.

The 8-inch fast capacitive touchscreen offers lots of color customization options. Here are some of the remarkable features of this stereo.

  • Digital multimedia receiver but does not play CDs and comes with AM/FM Tuner.
  • Built-in Bluetooth for wireless connectivity with your device and hands-free calling.
  • Compatible with android auto and apple car play.
  • Supports Siri Eye free, which means controlling your stereo with your voice, giving commands, listening to text messages, playing music, etc.
  • 6 channel pre-outs for the front, rear, and subwoofer.

Pioneer DMH-C5500NEX Modular 8'' Capacitive Multimedia Receiver with Apple CarPlay, Android Auto, Built-in Bluetooth, SiriusXM Ready, Remote Control Included

Pioneer AVH-W4500NEX

Pioneer AVH-W4500NEX is a double din stereo with in-dash CD/DVD player. It has a less responsive 6.94-inch resistive touchscreen display and the 4 volts pre-outs.

Other features of this stereo include:

  • Plays songs via Bluetooth and hands-free calling.
  • HD AM/FM tuner and also compatible with Apple CarPlay and Android auto.
  • The front face of this receiver is detachable, which means you can protect it from theft.
  • It contains low and high bandpass filters, and you can also adjust crossover points.

Pioneer AVH-W4500NEX Double Din Wireless Mirroring Android Auto, Apple Carplay In-Dash DVD/CD Car Stereo Receiver


Connecting an external speaker or amplifier without a pre-out on the head unit would limit your options when it comes to your sound system.

Pioneer car stereos have three pre-outs to provide a clean and clear sound.