Line Out vs Speaker Out: What’s the Difference? (Explained!)

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If you’re someone who works with professional audio gear, I’m sure you have heard of the terms “line out” and “speaker out.” Have you been wondering about what they are? You are at the right place so read along to find out. But first, let’s start with the basics: What’s the difference between Line Out and Speaker Out?

Line Out is an output port meant to deliver line-level signals from one device to another. On the other hand, Speaker Out is an audio output that delivers an amplified audio signal meant to drive speakers and get them to work.

What is Line Out?

A line out is an audio output port used to transmit line-level audio signals from one audio device to another. But what exactly is a line-level signal?

This is the standard audio level used to transfer audio signals from one audio device to the other with less to no signal loss. This is the standard audio output signal from instruments like keyboards, digital piano, synths, and audio devices like preamps and amps. 

All these instruments and audio devices have a line output (or line out) port that allows them to line-level audio signals to other devices for further processing.

Line out can also be referred to as audio out. A line out outputs only line-level audio signals. Line outs are used to send these line-level signals out of your audio device or instrument. You should note that, technically, any audio output that sends out line-level signals can also be referred to as a line out, not only those that are labeled so. 

The exact opposite of Line Out is Line In. Line In is an audio input port found on audio devices that receives line-level input. I talked about the key differences between Line Out and Line In in my previous article. And you should definitely check it out.

What is Speaker Out?

Speaker output (or speaker out) is also another audio output port that is very usually known by audio professionals. They are commonly found on amp heads and power amplifiers. But what exactly are they?

Just as the name depicts, speaker out is a port on your audio device where speakers are connected to. Speaker outputs transmit speaker-level audio signals to speakers. Let me explain briefly what speaker-level audio signals are to those of you who don’t know.

Speaker-level signals are amplified audio signals meant to drive speakers. This is a very strong audio signal that supplies speakers with enough voltage and gets them to work. Their signal strength is greater than that of line-level signals. And that’s because speaker-level signals are basically line-level signals that are amplified.

Is Line Out The Same as Speaker Out?

No, a line out is not the same as a speaker out. Line outputs and speaker outputs are two different ports. A line out is an audio port that transmits line-level signals, while speaker out ports transmit speaker level signals. The audio signals carried by line outs are weaker than the signals carried by speaker-outs.

Though line out and speaker outs are both audio output ports, they are not the same. I will talk more about the differences between line outputs and speaker outputs next, so read along.

Difference Between Line Out and Speaker Out

Signal strength of audio output

As we’ve already discussed, Line Outs are designed to output a line-level while Speaker Outs are meant to output speaker-level signals. And the main difference between these two is the signal strength.

Audio signals from line outputs are much weaker than audio signals from a speaker out. And here’s why.

Line output does not come with built-in amplifiers. This output port is designed to be connected to external means of amplification. They need to be connected to an external source of amplification in order to increase their signal strength. This is why line-level signals are also known as pre-amplification signals.

Line level signals from line outputs turn into speaker level signals after they are processed through a power amplifier. Unlike line outs, speaker outs come with built-in amplification. This built-in amplifier boosts the audio signal into a stronger speaker signal. And then, the amplified signal is transmitted by speaker outputs. That is why speaker-level signals are stronger than line-level signals.

Speaker-level signals are also referred to as post-amplification signals. This is because they are the type of signal you get from your audio setup after the power amplification stage.

Output Impedance

Impedance, which is measured in ohms, is the measure of the resistance to alternating current presented by an object. When your equipment or audio device outputs audio signals, we can say it has an output impedance. Line outputs have an output impedance of about 100-600 ohms.

Speaker outs on most amplifiers come with an output impedance that is around 2 to 16 ohms. Speaker outs are ideal for driving low impedance loads, while line outputs are designed to drive high impedance loads. Line outs can drive loads with an impedance of about 10,000 ohms.

Voltage

Speaker out transmits speaker level signals. Speaker-level signals have a higher voltage than line-level signals. That is why they are able to drive speakers. Speaker outputs have a voltage of about 10 volts or more. 

Audio signals that are speaker-level signals are typically transmitted through speaker cables. The audio signals carried by the speaker out have voltages far greater than that of line outs.

In most professional audio consoles and gear, line outputs carry a voltage of about 1.23 volts. The voltage in the line outputs of pro audio devices can reach about 2 volts.

Nature of Signal and Output Signal Purity

Since line outs do not have built-in amplifiers, they deliver unpowered signals. This means the audio signals line out transmits do not undergo any form of step-up. As a result, line outputs deliver audio signals that are pure or closer to their pure form. Such audio signals do not have a lot of noise in them.

Speaker outputs deliver amplified audio signals. Amplified sounds usually have some form of noise in them. When sound is made louder, some amount of distortion and hissing is introduced into the sound. This makes the sound less clean. Therefore, Line out outputs are relatively better and have cleaner sound output than speaker out.

Can You Use Line Out For Speakers?

You cannot use a line out for speakers. Speakers require- speaker-level signals to work. However, Line outs deliver line-level signals, which is a weak audio signal compared to speaker-level signals. Hence, Line out will not be able to provide speakers with enough power needed for them to work.

When you connect your speakers to the line out of your audio device, you will produce little to no sound at all. According to Wikipedia, you can short circuit the output circuit of your audio device if you connect a line out to a loudspeaker. However, this usually occurs in extreme cases. What this means is that you can even damage your speakers when you connect them into a line out.

Therefore, you should only connect speakers to speaker outputs. Line outs should also be connected to the appropriate line inputs found in audio devices such as amplifiers, mixers, etc.

Can You Connect Headphones to Line Out or Speaker Out?

It’s not ideal to plug headphones into a line out. And you’ll damage the headphones when you plug them in. Line out will not supply headphones with enough power to drive them, and a speaker out will supply too much power than the headphones can handle. Ideally, you want to plug headphones in a headphone out (or headphone jack)

As we’ve already discussed, line outs send out line-level audio signals. Line-level signals are not strong enough to drive headphones. I explained this in greater detail in my article on Line Out vs. Headphone Out, and you should definitely check it out if you want to learn more.

When you connect a headphone to a line out, you’ll get less to no sound through the headphones. I’ve actually tried this a couple of times and had the same result. You’ll either get very little sound or no sound at all.

And it’s a very bad idea to connect a headphone to a speaker out. And you should never connect your headphones to speaker output. Headphones don’t require a lot of power and voltage to drive them. They have tiny voice coils that need just a small amplified line-level signal to get them to work.

Speaker out sends out a speaker-level audio signal which is too powerful for headphones to handle. This audio signal is meant to drive loudspeakers which require lots of electrical power to work. You’ll damage your headphones when you plug them into a speaker. And you should never do it.

You want to plug your headphones into a headphone output (or headphone jack). Headphone outputs will have a headphone amplifier built into them. And these amplifiers are specially designed for the power requirement of headphones. That’s how you’ll get the most out of your headphones. 

Can You Connect Microphones to Line Out or Speaker Out?

You cannot connect microphones to line-outs or speaker-outs. This is because a microphone is designed to send signals into an audio device. Hence a microphone must be connected to an input and not output. For microphone signals to enter an audio device, they must be connected to a line out or an XLR input port.

One of the mistakes people make is to connect plugs into ports simply because they fit. It is not advisable to assume the same interfaces, ports, and jacks can be used for different purposes simply because they fit.

Line out, and speaker out ports are built to transmit signals out of audio devices. They are output ports and not input. This means line out and speaker out cannot provide a pathway for the transmission of microphone signals into audio devices like mixers, amplifiers, etc. Hence, when you connect microphones to line out or speaker out ports, you will hear virtually no sound.

Conclusion

A line out is an output port. This port transmits line-level audio signals from one audio device to another. A speaker out is also an output port on your audio device where speakers can be connected to. 

However, speaker out ports transmits speaker-level audio signals instead of line-level audio signals. Audio signals transmitted from the speaker-out ports are amplified and are stronger than line-out signals.