Amplifiers are a crucial part of audio production especially for those that play live sets or use equipment that needs power for amplification of audio signals.
Electric guitars are one kind of equipment that requires an amp in order to be used to its full potential.
For newbies to guitar playing, an amp may seem out of reach if they don’t have the money to buy one. Trust me we’ve all been there and it’s really not easy.
In the absence of an amp, most people wonder what they could use as an amplifier.
One question a newbie guitar player posed to me the other days was : Can you use a speaker as a guitar amp?
This post will therefore answer this query and provide context so you understand amps a lot better.
With that said, Can you use a speaker as a guitar amp?
You can use speaker’s as guitar amps but you need the help of an audio interface or RCA Cable adapters to act as intermediaries between your guitar and speakers.
You can’t use a speaker directly as a guitar amp because most speakers are only meant to produce audio output and not directly act as amplifiers. Most have no amps in them that can create a larger copy of the original signal.
How do amplifiers work?
To understand why directly using a speaker as an amplifier is not possible let’s get into how exactly an amplifier works.
An amplifier basically takes an input audio signal from a source which could be a guitar, laptop etc, and it then creates a larger copy of the original signal before it’s sent to your speakers.
To effectively do this, the amplifier needs a source of power.
It gets this power from your electricity supply which is usually mains electricity. This power is then sent directly to the power supply within the amplifier.
Here, it’s then converted from an alternating current (AC) to a direct one (DC), which only flows in one direction, and is sent on to the transistor.
The role of the transistor is to work like a valve, and determine the amount of current that flows through the circuit at any time.
The transistor bases that decision on the size of the input signal from the source.
This means that …the larger the signal, the more the transistor allows more current to flow, which in turn creates a greater amplification.
The volume control is the final part, which decides how much of this current is passed through to go to the speakers.
How do speakers work?
Now that we have a working understanding of how amplifiers work we should also get into how speakers work to understand our question better..
Speakers basically work by converting electrical energy into mechanical energy which is sometimes called motion.
Mechanical energy then compresses air and converts the motion into sound energy or sound pressure level.
When an electric current is sent through a coil of wire, it induces a magnetic field.
In speakers, current is sent through the voice coil which then produces an electric field that interacts
with the magnetic field of the permanent magnet which is attached to the speaker.
Obviously its a known fact that; Like charges repel each other and different charges attract.
As an audio signal is sent through the voice coil and the waveform moves up and down, the voice coil is then attracted and repelled by the permanent magnet.
This makes the cone that the voice coil is attached to move back and forth.
This back and forth motion creates pressure waves in the air and this is what we perceive as sound.
How to Connect guitar to speakers
Typically, a simple adapter cable won’t work with a guitar. For example, simply converting your ¼ inch guitar jack into a 3.5mm audio jack on to your phone speakers wont work because there’s really no amplifier involved.
On the other hand, a stereo speaker that utilizes rca inputs for left and right audio usually have an amp present which is used to strengthen the single audio signal into dual signal and played in both speakers.
With stereo speakers that use rca input, you can simply use a ¼ inch to RCA jack adapter and plug your guitar in.
Your stereo speakers have a built-in amp to strengthen the sound signal and split them to both speakers.
This can be used to amplify sound signals from your guitar allowing you to use the speaker as an amplifier.
Using an Audio Interface
The job of an audio interface is to convert analog signals from your guitar into digital signals that can be used by a computer.
This allows you to connect your guitar to a computer and play it through the computer speakers or speakers attached to your computer.
I would recommend using an audio interface if you don’t have an amp.
With an audio interface you can do many more things than a regular amp.
For example, you can use an audio interface to record your guitar and add different sound effects to your guitar.
Emulating how an amp sounds is just one of the many things that an audio interface can help you do – it’s known as ‘amp modeler’.
There are literally thousands of plugins that you can use to change how your guitar sounds – without having to buy effects pedals separately.