Instrument vs Speaker Cable

[jasaco]

Any way to tell without peeling off the pink insulation (which goes all around- you can't see the wires or connections)? Both ends are 1/4".

[GNAPPI]

Looks like a heavy duty speaker cab cable to me. It's too inflexible to be usable for most instruments

[child as audience]

I’m going with speaker as well. Looks like a 12AWG.

If if you can tell if it’s shielded or not, that’s the tell as instrument cable is shielded - speaker cable is not.

Using speaker cable as instrument cable won’t hurt anything - but being unshielded, it will invite noise from every which way.

Using instrument cable as speaker cable is right out.

[jasaco]

Using instrument cable as speaker cable is right out.

Thanks guys. What happens if you use an instrument cable as a speaker cable?

[child as audience]

I’m really naming the extreme things here, but it should be enough to let you know potentially what could happen - and that you wouldn’t want to risk it.
- Fire
- Amp damage
- Speaker damage

Less extreme:
- Damage the instrument cable

Even less extreme (but, possibly the most sinful)
- Loss of tone

[DRS]

Instrument cables have a small copper conductor, a plastic dielectric, and a braided copper shield that acts as the ground.
Speaker cables have 2 large copper conductors and no shielding.
Unscrew the jack and look inside. Pull back the pink plastic sheath and look at the soldering.
The other way is if you plug your guitar into an amp using the cable and it hums like a sob, it's a speaker cable.

[sgosnell]

Nothing bad will happen unless the wires inside are really small, and the volume is really high. Using 1/4" plugs for speakers is poor practice because it's so easy to short the connection, but some manufacturers haven't updated so it's sometimes necessary. I use Speakon connections whenever possible, and I've replaced a couple of 1/4" jacks in cabinets with Speakon jacks. It's easy to do. The problem really is with amps that use 1/4" jacks, because it's difficult if not impossible to replace those.

[KirkP]

Nothing bad will happen unless the wires inside are really small, and the volume is really high. Using 1/4" plugs for speakers is poor practice because it's so easy to short the connection, but some manufacturers haven't updated so it's sometimes necessary.

The risk of a short in a speaker connector is a good point. I think there is much more risk with solid state amps than tube amps. Most tube amps can tolerate a shorted output for reasonable amount of time, but may be damaged quickly by an open circuit. The situation is reversed for solid state amps, although these days I think they are better protected against shorts.

Other than the risk of shorts, it’s probably fine to use shielded cable for speakers if the total resistance of center conductor and shield is much less than the impedance of the speaker. One thought would be short the tip and sleeve on one end, then use an ohmmeter to measure the resistance between the tip and sleeve on the other end. If the resistance is much less than the speaker impedance (maybe 10%?) it should be fine. But it would require a good quality ohmmeter that can measure down to the 1 ohm range.

[cosmic gumbo]

From the Carvin Amp website:

Using an instrument cable in place of your speaker cable can cause catastrophic damage to your amplifier. While your amp will still work initially, the high amount of current going through the instrument cable’s small gauge wire can actually melt the cable!

[KirkP]

That’s probably true for cheap cable, but I think most high quality shielded cables could handle it. For example Canare GS-6 has an AWG 18 center conductor. The total resistance per 1000 foot (center conductor plus shield) is about 13 ohms, which is 0.13 ohms per 10 feet. When a resistance that low is in series with a 4 or 8 ohm speaker it’s not going to significantly heat the cable.

I can think of one exception. If one of the end connections is botched the resistance could be high at that point, creating a potential hot-spot.

I’m way over-thinking this, but that’s me.

[sgosnell]

Some instrument cables, the cheap ones, have very thin inner conductors which won't carry huge amounts of current. But any reasonable sized cable will work without issues. It may not sound quite as good as heavy speaker cable, but it shouldn't be dangerous. The cable in the OP looks as if it could carry plenty of current to run multiple speakers. It's not as if the amp is putting out all that much to the speaker anyway.

[cosmic gumbo]

[oldane]

Nothing bad will happen unless the wires inside are really small, and the volume is really high. Using 1/4" plugs for speakers is poor practice because it's so easy to short the connection, but some manufacturers haven't updated so it's sometimes necessary. I use Speakon connections whenever possible, and I've replaced a couple of 1/4" jacks in cabinets with Speakon jacks. It's easy to do. The problem really is with amps that use 1/4" jacks, because it's difficult if not impossible to replace those.

Agree 100%. I much prefer SpeakOn connectors for speaker cables.

[jasaco]

Thanks, all. To be clear, I never envisioned using the cable to connect an amplifier speaker. If anything, it would be to connect a PA speaker from the powered mixer...

[marcwhy]

I know it's been discussed on the Forum before, but here is a helpful article on the differences between cable types.

Marc

[Jimmy Mack]

Nice. Thanks marcwhy. Things I knew, but now I can explain better when someone (and they will) ask!

[rob taft]

Marc, thanks I hadn't considered the difference for powered monitors.

[jasguitar]

Nothing bad will happen unless the wires inside are really small, and the volume is really high. Using 1/4" plugs for speakers is poor practice because it's so easy to short the connection, but some manufacturers haven't updated so it's sometimes necessary. I use Speakon connections whenever possible, and I've replaced a couple of 1/4" jacks in cabinets with Speakon jacks. It's easy to do. The problem really is with amps that use 1/4" jacks, because it's difficult if not impossible to replace those.

Could you point me to a resource about swapping 1/4" speaker inputs with a Speakon input?

[nevershouldhavesoldit]

I’m really naming the extreme things here, but it should be enough to let you know potentially what could happen - and that you wouldn’t want to risk it.
- Fire
- Amp damage
- Speaker damage

Less extreme:
- Damage the instrument cable

Even less extreme (but, possibly the most sinful)
- Loss of tone

None of those things will happen if you use a speaker cable from your guitar to your amp. The only difference from using a "speaker cable" (i.e. an unshielded, heavy gauge 2 conductor cable) as a guitar cable is that it will be noisier. Since most speaker cables use parallel conductors and are unshielded, there will be less cable capacitance, which will make the tone a bit brighter with a run of more than 10 to 15 feet.

To find out if the cable is for low (ie. instrument) level signal or high (speaker), just unscrew the plug's barrel and look at the wires. If there's a braided shield soldered to the long ground contact and the center conductor is relatively thin and emerges from the center of a round insulating core, it's a guitar cable. If there's no shield and there are two larger wires running parallel to each other in the core (e.g. as large as the conductors in the "zip cord" used in small lamp and home appliance power cables), it's speaker cable.

But if you use guitar cable between an amplifier's speaker output and a speaker, it will not be able to handle more than minimal wattage. So it can overheat if you're pumping 50 watts through it (which would be unusually high as a steady state power output for a guitar amp, even on a gig). You shouldn't do this, but you'd have to be pushing a lot of power through it to come anywhere close to starting a fire. I doubt that it could even get hot enough to soften a solder joint between a conductor and the plug. Of couse, if it did cause disruption of a poorly done solder joint, the open circuit could damage the amplifier if it has no output protecton against an open circuit. You wouldn't hear any difference in the sound except a diminution of volume because some of the amp's output power would be converted to heat and never reach the speaker.

[sgosnell]

Could you point me to a resource about swapping 1/4" speaker inputs with a Speakon input?

I don't know of a resource. I just do the work as necessary. It usually involves enlarging the hole in the back and doing the resoldering/soldering, and making the pilot holes for the screws. It's basic woodworking and soldering, and I haven't done any internet searches for how to do those, because I've been doing it for 60 years or so. The inputs are available from Mouser or Ebay.

[AllanAllen]

None of those things will happen if you use a speaker cable from your guitar to your amp. The only difference from using a "speaker cable" (i.e. an unshielded, heavy gauge 2 conductor cable) as a guitar cable is that it will be noisier. Since most speaker cables use parallel conductors and are unshielded, there will be less cable capacitance, which will make the tone a bit brighter with a run of more than 10 to 15 feet.

You got it wrong, the list is for potential damage due to an instrument cable going from amp to speaker.

[GuyBoden]

The electrons will still move through the conductor, and they will not notice any difference.

[nevershouldhavesoldit]

You got it wrong, the list is for potential damage due to an instrument cable going from amp to speaker.

Keep reading.....

On second thought, let me help you:

...But if you use guitar cable between an amplifier's speaker output and a speaker, it will not be able to handle more than minimal wattage. So it can overheat if you're pumping 50 watts through it (which would be unusually high as a steady state power output for a guitar amp, even on a gig). You shouldn't do this, but you'd have to be pushing a lot of power through it to come anywhere close to starting a fire. I doubt that it could even get hot enough to soften a solder joint between a conductor and the plug. Of couse, if it did cause disruption of a poorly done solder joint, the open circuit could damage the amplifier if it has no output protecton against an open circuit. You wouldn't hear any difference in the sound except a diminution of volume because some of the amp's output power would be converted to heat and never reach the speaker.

[RJVB]

The problem really is with amps that use 1/4" jacks, because it's difficult if not impossible to replace those.

Make adapter dongles, figuring out a way to put the jacks in semi-permanently?

[pauln]

Any way to tell without peeling off the pink insulation (which goes all around- you can't see the wires or connections)? Both ends are 1/4".

Just peel it off to be sure, then replace it with electrical tape (do it like an electrician and use the most tape that will allow clearing the metal screw-on cover).