What’s the Difference Between Speaker Cables and Guitar Cables? Why Does it Matter?

What’s the Difference Between Speaker Cables and Guitar Cables? Why Does it Matter?

October 07, 2016 19 Comments

Guitar Cable

Somewhere along the line somebody probably told you “Don’t ever use guitar cables for speakers and vice versa!” If not you will be glad you noticed this article because it might save you some trouble down the road. What seems confusing is that from outward appearances the two cables can look much the same, if not identical. The plugs are interchangeable in most cases as well. So let’s take a look at why they are different, what they are optimized for, and why they don’t make good substitutions for one another.

Instrument (guitar) cables are designed to transfer the very small signal your guitar pickups generate or the line level signals from a preamp or mixer to an amplifier input. They need to do this without collecting a lot of outside interference. This is important because any small electrical signals it picks up on the way to your amp input will be amplified right along with your instrument! To prevent this, guitar cables have a small central conductor to carry the low level signal to the amp and a large outer shield of twisted or braided copper to ground out interference before it gets into your signal chain. 

Speaker cables must carry a much more powerful signal as they come after your amplifier has boosted the signal level many times over (how loud is your amplifier compared to what your electric guitar sounds like unplugged?) Those high AC currents allow your power amp to move large, heavy speakers and a lot of air to create sound. So speaker cables must have very large conductors compared to instrument cables. On the other hand because the signal level they carry is so high, outside interference isn’t a problem (without being amplified it can’t compete with your amp’s output), so speaker cables do not have an outer ground shield like your instrument cables.

It is easy to see how both cables have different designs so they can handle different jobs. But why is it so important not to confuse the two?

If you were to use a speaker cable to plug in your guitar it would collect all the electrical interference around you like an antenna and inject it into your amp input along with your guitar signal because it doesn’t have the outer shield. By the time that noise was boosted by your entire amp it would come out just as loud as your guitar and would probably only be useful for getting club managers to fire the band.

Now if you put an instrument cable between your amp output and the speaker, the small center conductor cannot handle the high power output current and can overheat, generate resistance that affects your output load (bad for your amplifier’s output section!), and might even melt down or catch fire in extreme cases! The shielding on an instrument cable creates a capacitor with the inside conductor that your amplifier may not like. This could send your amp into an oscillation and potentially cause damage. Because of this it is very important for you to know which of your cables are which and that you can tell them apart even under low light stage conditions.

If you are unfamiliar with a cable, in a pinch you can often tell the difference by unscrewing the end of the cable and looking at the wire coming in. If the cable splits into two fairly thick even wires that are side-by-side, it is a speaker cable. If it has one wire in the middle and many strands of twisted or braided copper wire wrapped around the outside the other, it is an instrument cable. Some fancy, high quality cables might have extra center conductors, so don’t let that confuse you- they’re wired in parallel. The outer shield is what is important no matter how many wires are in the middle. Fortunately most quality cable makers also print the type of cable on the wire itself which can be a big help if the end of the cable isn’t designed to unscrew.

Take some time out to check all your cables so you know which are which. You might even want to mark them with colored tape so they are easy to tell apart next time you’re fishing in your gig bag for a replacement only moments before downbeat. Knowing every part of your system is wired correctly will give you added confidence, and you will be rewarded with great sound and reliability in the future.

19 Responses

Wayne
Wayne

March 03, 2017

Very good to get this clear, amps can be damaged by using the wrong cable which can be an expensive experience.
I’ve used a patch lead at low volume to check an amp/ speaker but cranked you could overload an instrument cable to the point it catches fire.
Worse still it could irreversibley damage an expensive amp.
Thanks for getting this across so clearly
Wayner

AL
AL

February 02, 2017

can I used a speaker cable from my special effect pedal to my amp and a inst.cable from effect to guitar?

Tim
Tim

October 11, 2016

Still confused. You talk about instrument (guitar) cables at first in the paragraph, then later refer to them as audio cables…that’s confusing. And how about microphone cables…how do they handle a guitar going thru an audio cable to a pre-amp that then runs a mic cable to a non-powered mixer that has mic cables running to powered speakers that accept the mic cable…you are leaving a lot out of the picture of what is going on out here…

Jon Cotters
Jon Cotters

October 10, 2016

I have used 12 Ga speaker cables with my MarkBass rigs for some time, but now I know why. I really do appreciate you articles. Thanks!

Jim colbert
Jim colbert

October 09, 2016

Excellent ..

Randy karr
Randy karr

October 09, 2016

Thanks for the info on cables. These are some great articles. Keep up the good work. I have never used carvin equip. I have heard good reports on carvin for many years . I may have to try some of your products. Randy karr

Bobby Brown
Bobby Brown

October 09, 2016

Instrument cables are shielded, speaker cables are not shielded.

Durandal
Durandal

October 09, 2016

Can we please stop using 1/4" jacks for speaker cabinets? Guitar cabs really should migrate to Speakon connections.

Christopher Lingsch
Christopher Lingsch

October 08, 2016

Very helpful on identifying them by unscrewing the jack end and looking at the wires.

matthew fowler
matthew fowler

October 08, 2016

Can I use a double-ended(red/black) 6 ft. to run from my Marshall all-tube DSL 40w Vintage Amp to my 4 × 12 speaker cabinet without damaging the amp or cabinet?So,black to black,red to red okay right?

Bill Greene
Bill Greene

October 08, 2016

Very good information!

John Burris
John Burris

October 08, 2016

Good information but to the rookies a visual always helps in all information shared. Thanks!

Chris Bublawek
Chris Bublawek

October 08, 2016

Great Tidbit of information. Love these little articles.

Wayne Bolon
Wayne Bolon

October 08, 2016

If, two cables looked the same, I would spray paint the guitar cable end yellow and the speaker cable red a different color for easy identification. Different colored ends for each type of cable would be an easy fix.

Circio
Circio

October 08, 2016

Great article! A lot of young kids have no idea of the difference.

Joe Phillips
Joe Phillips

October 08, 2016

These blog posts are fantastic. This is the second one I’ve read. I’m going back to read earlier ones. I’ve played guitar for 50+ years and frankly, have absorbed very little about the real workings of amps and electronics. While I’m unlikely to work on these things myself, it’s gratifying to understand them better. Thanks. Keep’em coming.

Dale Burke
Dale Burke

October 08, 2016

Very useful info. I made the mistake of using a speaker cable to connect my guitar to an amp a number of years ago. As soon as I powered up my amp it produced an very loud squeal. Luckily I shut it down before any damage occurred.

Don McBride
Don McBride

October 08, 2016

Thanks for the information. Have played for 40 years and didn’t know that. I will definitely be checking my cables.

Alan Kaye
Alan Kaye

October 08, 2016

Good one! You always hear this, then someone says they ignored it and never had a problem. Now lots more people are aware of the difference, in clear, simple terms.

Leave a comment

Comments will be approved before showing up.


Also in Guitar / Bass Amplifier Info & Education

Jack of All Trades: Build a Modular Pedalboard
Jack of All Trades: Build a Modular Pedalboard Part 1

February 20, 2018

In light of the rapidly growing popularity of boutique guitar pedals, more and more players are finding themselves confronted by the challenge of moving and setting up all those different pedals. Gigging musicians have an even more difficult challenge of addressing a wide variety of venues and styles in an age when almost every gig is a one-nighter. 

Read More

Warning Signs That You Are Overpowering Your Bass Guitar Cabinet
Warning Signs That You Are Overpowering Your Bass Guitar Cabinet

October 03, 2017 13 Comments

Even if you’ve matched your bass head and cab properly impedance wise and set your amp for clean sound, sending simply too much power to your bass cab can result in blown speakers. This often happens when you are using a rig you are unfamiliar with, as we tend to know the limitations of our own equipment and have chosen that setup for a reason. Borrowing another bassist’s amp or using a backline rig only to blow it up is definitely not a great feeling.

Read More

Quick Clips: BX250 Micro Bass Amp and 1x15 Cab

September 26, 2017

Quick Clips: BX250 Micro Bass Amp and 1x15 Cab

Even with all the EQ controls set to Zero, you can get a wide range of tones from one knob on the BX250 250W Micro Bass Amp HeadWatch the video to check it out.

Read More