Speaker Cable vs Instrument Cable: You Need to Know the Difference

Speaker cables and instrument cables look very similar to each other, but it is important to know the difference between them.  Using the wrong cord for the wrong application can cause unnecessary noise, tone distortion, reduced speaker output, or even worse, damage to your amp.   So what is the difference between the two and how do we know which ones to use?

An instrument cable is used to carry a low power signal, that will generally need to be amplified at some point.  An example of this is, from a guitar to an amplifier or in an effects loop.  For that reason it doesn’t need to carry a lot of current and has a high resistance.  Instrument cables also need to have shielding to prevent unwanted interference.  More expensive cables will generally have better shielding than cheaper ones

A speaker cable is used to carry a high power signal, which is used to power speakers,  for example between an amp and your speakers, or between a head and a cabinet.   Speaker cables are low impedance and don’t require as much shielding as instrument cables do, because any interference won’t be significant enough to degrade the signal.

What can happen if you use the wrong cable?

If you use a speaker cable as an instrument cable, you will probably get unwanted noise and distortion, due to the fact that speaker cables aren’t shielded as well as instrument cables.   Buzzes and hums can be caused by lights, a/c adapters, or other electronics and can interfere with your tone, when using a speaker cable.

On the other hand, if you use an instrument cable as a speaker cable, you will also probably also get distortion and much lower speaker output, since the amplifier is trying to push a lot of juice through a high impedance cable.  At high volumes this can cause your amp to overheat and even cause serious damage to your equipment.

So How Can You Tell the Difference?

Generally speaker cables tend to be thicker than instrument cables, since they need to carry more juice.  Usually cables will have their specifications written on them.   It can be a little complicated to figure out whether which cable you need to use but think of it this way.   An instrument cable is used when you want  to send your tone or sound to be shaped or sculpted.  For example when sending your tone through an effects pedal or board.  You will also want to use an instrument cable in an effects loop on your amp or on your preamp out jack on your guitar amp.  A speaker cable is used to carry a powerful signal to unpowered speakers.