Can you use an instrument cable to connect an amp head and speaker cab? What kind of cables are used for these kinds of music equipment? It is important to know the differences between cable types to avoid any problems that may arise from any mistakes.
Even for experienced musicians, cables can get quite confusing. But nothing is more baffling than the cables intended for instruments and speakers, since they look very similar to one another. Without unscrewing and inspecting a guitar cable, it would be easy to mistake it for a speaker cable and vice-versa.
However, there are glaring dissimilarities between what you would use for your instrument and the one that you need to connect your head and cab with. They are designed by engineers with a focus on the specific purpose of each cable. Since both cables emit different levels of signal and power, they will also have differing requirements when it comes to components.
Amplifier heads and speaker cabinets
Before we answer the question whether you can use instrument cables to connect head and cab, we need to understand this type of setup.
A head and cab is a two-piece rig that’s commonly used by guitarists and bassists. This format is preferred by guitar players who need to play much louder live.
The head refers to the amplifier where all the controls for shaping your tone are laid out. This is also where you plug in the other end of the cable that’s connected to your instrument.
The cab is a speaker or a set of speakers that are tasked to convert the signals into sound. Simply put, the speakers are responsible for making your ideas emanate into the outside world.
Combo amplifiers are just a combination of heads and cabs, but in an all-in-one setup. They cannot be separated unlike amp heads and speaker cabs, which can be bought and transported individually. Because combo amps are built-in, their sizes can be limited and so are their headroom and power capacity.
What cable is used to connect head to cab?
A speaker cable is what you need to properly connect an amp head to the cab. Never ever use an instrument cable in place of a speaker cable.
Using an instrument cable to connect your head to the cab can cause some issues, or even totally damage your amplifier. Instrument cables are usually shielded to prevent signal interference. However, this capacitive factor can actually harm your amplifier.
The instrument cable will also not be able to withstand higher amounts of current and the longer you use them, the more chances it could melt under such circumstances. The smaller wire gauges of an instrument cable makes it more susceptible to the flow of excessive electrical energy, and if it gives out, the amp could short and cease from functioning for good.
Here are a few examples of some head-to-cab cables from well-known brands:
- Andertons Pro Sound 6.3mm Jack to Jack Speaker Lead
- D’Addario Speaker Cable
- Musician’s Gear 12-Gauge 1/4″ – 1/4″ Speaker Cable
- Mogami GOLD SPEAKER-03 Amplifier-to-Cabinet Speaker Cable
- Monster Prolink Studio Pro 2000 Speaker Cable
- MXR 3ft HD TS Speaker Cable
- Van Damme Jack to Jack (2x4mm High Power) Speaker Cable
How to connect amp head to speaker cabinet
Before proceeding with hooking up your head and cab, always take note first of their impedance.
Do not plug the cables to connect the head and the cab if your cabinet’s impedance is lower than that of the amp’s output, this can destroy your amp severely.
Here are some simple ways to connect your head and cab:
- Single speaker cabinet
Plug the speaker cable into your amp head’s output jack (the amp head should match the cabinet’s impedance).
Plug the other end of the speaker cable into your cab’s input jack.
- Multiple speaker cabinets
Plug the speaker cable into the output jack of the speaker cabinet, then plug the other end into the input of the second speaker cabinet. This way of connecting speakers is called parallel wiring.
Combining two speaker cabinets with the same impedance rating in parallel will make the impedance cut in half. That means a pair of eight-ohm cabs will become four ohms when wired in parallel.
Can you use an instrument cable to connect head and cab?
If you are still wondering whether you can use instrument cables to connect your head and cab, the answer is “no.” And since they look alike, always be careful and double check what kind of cables they are before connecting them to any device.
Instrument cables are low power and high impedance. They are designed to transmit weaker, unamplified signals coming from your bass or guitar. On the contrary, speaker cables have high power and low impedance. They are intended to carry a much stronger signal from your amp and into the speakers.
How to tell the two cables apart
Now that you know that you can’t use an instrument cable to connect your head and cab, it is also important to be able to tell them apart. It’s not impossible for musicians to accidentally interchange the two, leading to disastrous results.
By unscrewing your cable’s connector, you will see what it’s made out of. An instrument cable consists of a single inner wire that is much smaller, flexible and lightweight compared to the ones on a speaker cable. These thin wires run through a braided shield conductor that functions as the ground connection.
Meanwhile, speaker cables have two wire conductors instead of just one, and they come with thicker gauges in order to allow a greater flow of signal.
