Many ports on the back of your computer are self-explanatory: the power socket, Ethernet port, HDMI out for your monitor, and plenty of USB ports. But the multicolor audio jacks on the back aren’t as well-known.
Depending on your machine, you might have a few or several of these. And picking the right one is essential for avoiding problems and having your computer’s audio sound right.
Meet your PC’s audio jacks
The collection of colored jacks on the back of your desktop are all related to analog audio. Each one takes a 3.5mm cable (also called an aux cable). They use different colors to indicate their purpose; they might also have icons or bits of text to help identify them.
These aren’t like USB port colors, where newer, faster ones are backward-compatible with older devices. Instead, each port has a purpose, so it’s vital that you plug the right cable into the corresponding jack. If you do this improperly, your computer sound won’t work or will have issues.
Depending on the age of your computer and how expensive the motherboard is, you might have as few as three jacks or as many as six. Three is standard on older or basic computers with stereo sound, while more powerful machines will have up to six to support full surround sound.
Let’s walk through each color in turn, starting with the three common jacks.
Green jack: stereo output
Of all the colors, the green jack is likely the one you’ve used most. This is the line out stereo port, which outputs both the left and right channels of audio from your computer to speakers or headphones.
If you use wired headphones with your computer or stereo speakers that have an aux cable, plug them in here. They’ll work in the same way as connecting speakers/headphones to the aux port on other devices (like old smartphones or handheld game consoles).
Beyond audio, did you know you can connect crazy items to your headphone jack?
Pink jack: microphone input
The pink jack is the next one you’re likely to use, as it’s for microphone input. USB microphones are convenient and common today (whether headsets with a microphone attached or dedicated mics like the Yeti), but analog microphones still have their place.
For instance, you might connect a clip-on microphone for Windows voice commands, or a conference mic for speaking with multiple people in the room.
My previous gaming headset connected to a PC using a split cable that plugged into both the green and pink ports. You’ll know yours is like this if the male connector on the cable has three lines (called TRRS for Tip-Ring-Ring-Sleeve) instead of two (called TRS for Tip-Ring-Sleeve). The extra contact point is for the microphone.
If your headset has one cable and you need to connect two cables to your PC, you’ll need a 1 female to 2 male Y splitter. If your headset has two cables and you need to combine them into one to connect to your computer (common on laptops that have a combined mic/headphone cable), you need a 2 female to 1 male Y splitter.
Many desktop PCs have a second set of mic and headphone jacks on the front or top of the system. These are for convenience, allowing you to quickly connect another device. They perform the same function as the rear ones, though they may have more interference since they don’t connect directly to the motherboard.
Blue jack: line-in
The last of the three “classic” jacks is the least-used, but still important. It’s a line-in port, used for connecting devices that transmit at line level: the strength of audio components used when transmitting to each other.
Thus, this port is used to send audio from another device (other than a microphone) into your PC. For example, you can connect a tape deck to digitize old tapes, or monitor the output of another device.
Line level is much more powerful than microphone input, because it’s designed for a direct signal. If you plug a microphone into the blue port, you’ll barely be able to hear it. And it’s similar for the reverse: plugging a line-in device into the microphone port will result in blown-out, distorted audio because the microphone port is designed for a much weaker signal.
Orange, black, and gray: surround sound
The three remaining jacks, which your computer might have none, some, or all of, are all for surround sound. Standard surround sound is 5.1, which refers to five channels (center, front left, front right, rear left, and rear right) plus a subwoofer for bass.
The black jack is for your rear speakers, while the orange jack is for center speakers or a subwoofer, depending on your setup. Finally, the gray port is for connecting side speakers to reach 7.1 sound. This isn’t common, so it’s the port you’re least likely to use or have (my PC lacks this).
If you’re using a surround sound system, the speakers connected to the green audio jack serve as your “front speakers.”
Your computer may also feature an optical audio out port (labeled SPDIF for Sony/Philips Digital Interface), which is recognizable by the red light inside. This format isn’t as popular as audio over USB or analog cables; its use has dropped over time.
However, it still works for easy connections to a soundbar or similar. We’ve discussed the reasons to keep audio cables around, if you’re interested.
The ports on your PC handle core audio needs, but if you’re serious about sound, it’s worth investing in better equipment. Buying an audio interface with pre-amps lets you connect instruments, XLR mics, and similar to your computer with real-time monitoring. This will result in less interference and far more control.
Your PC’s audio jacks aren’t something you consider all the time, but it’s good to review what they’re for. Next time you need a new piece of audio equipment or get a new computer, you’ll know what your computer supports and what you need.