Tutorial – Connecting Microphone, Instrument, Mixer

Contents

  • 1 Identifying the sound ports on your computer
    • 1.1 PCs – Windows and Linux
    • 1.2 Macs
    • 1.3 USB devices
  • 2 Connecting a microphone, keyboard, guitar or mixer to your computer
  • 3 Testing your input connection
  • 4 Links

Identifying the sound ports on your computer

First of all you need to know the sound input capabilities of your computer.

PCs – Windows and Linux

Most desktop PCs (Windows and Linux) will have sound ports on the back of the computer similar to these illustrations.

The rear of a typical PC Color-coded inputs on a sound card
The rear of a typical PC The color-coded jacks on the sound card

The pink port is normally the microphone input, and is usually mono but might be stereo. The light blue port is normally the line input port and is usually stereo. The green port is normally the headphone output port, also usually stereo. Check your computer manual to be sure.

PC laptops vary widely in the types of sound input and output ports they provide, where they are on the laptop, and how they are labelled. Again, check your computer manual to be sure of the capabilities of your laptop, where the ports are and how they are labelled.

 

Macs

Macs do not generally have a microphone input port.

Audio connections on a Mac PowerBook Audio connections on an iMac
Audio connections on a PowerBook Audio connections on an iMac

In these illustrations of sound ports on Macs, the round port with the headphone symbol is the Line Output port. The round port beside the headphone port is the line input port.

Other Macs (Mini, Mac Pro, MacBook and MacBook Pro) are similarly equipped. Check your manual for the locations and labelling of these ports.

 

USB devices

For better audio quality, many people use an USB audio device. If you have such a device, attach your microphone and speakers to that device, and plug the device into your computer’s USB port.

 

USB Cable and Plug
USB Cable and Plug
USB Ports
USB Ports

 

Connecting a microphone, keyboard, guitar or mixer to your computer

Please click on the following links apropriate to the input device or instrument you wish to connect:

  • Microphone
  • Keyboard or Guitar
  • Mixer

 

Testing your input connection

Before you fire up Audacity you should use your computer’s sound control panel or the custom mixer application for your specific sound card, select the input device you want to use and verify that you are getting sound into the computer from that device.

Once you have verified that you are getting sound into the computer you can move on to getting that sound into Audacity.

If you are having trouble getting sound into Audacity there’s lots of help available on the Audacity Wiki.

Tutorial – Connecting a Microphone

Connecting a microphone to your computer

If your computer has a microphone input port

You’re all set. Just plug a compatible microphone into the microphone input port on your computer.

What do we mean by compatible? Any microphone with a permanently attached cord that ends in a mini-plug should work. Note that many sound cards provide battery voltage for mono electret microphones on the ring of a stereo mini-plug. Check your computer manual to be sure if this feature is provided. If it is, be sure to use a microphone that is designed to accommodate this.

A picture of a 1/8" (3.5mm) mono plug A picture of a 1/8" (3.5mm) stereo plug
A mono mini-plug A stereo mini-plug

A computer headset-mic combination is pretty much guaranteed to work. These microphones are not the highest quality, but can be had fairly inexpensively. If you’re just getting started and want to experiment without spending a lot of money, one of these would be a good choice. Just don’t be surprised if your recorded voice sounds a bit tinny or flat.

Desktop-standing microphones can be had for at little as $10 or as much as $500. Choosing a microphone is beyond the scope of this tutorial. Try searching the web for “computer microphones”, visit your local computer store, talk to your friends, or ask questions on the Audacity Forum.

Unless you are prepared to spend extra money for a microphone pre-amp or standalone mixer do not buy a microphone with an XLR connector:

A picture of an XLR connector
An XLR plug

If your computer does not have a microphone input port

Do not plug a microphone into the line input port on your computer. The volume will be way too low (the line input port does not apply the needed amplification to boost the very quiet signal from the microphone). You won’t break anything, but you will be very frustrated with the results.

Option 1 – Buy a microphone to USB adapter

These devices plug into a USB port on your computer, and have a microphone input jack (usually 1/8″).

Some options are the Griffin iMic, the M-Audio Transit USB and the Cakewalk UA-1G.

You will still need a compatible microphone. Be sure to carefully read the specifications of any adapter you are considering and make sure you get a microphone that will work with that interface.

Option 2 – Buy a USB microphone

These microphones are becoming more common. They combine a microphone and the USB adapter all in one package.

Models are available by Logitech, Samson, Nady and Audio-technica, among others.

Option 3 – Buy a mixer

This may be the most expensive option but provides the most flexibility.

Any inexpensive DJ mixer should include a microphone input. The electronics in the mixer will boost the microphone signal, and the output of the mixer will be connected to the line in port on your computer. The DJ mixer will also have inputs for turntables so you can use it record your LPs in preparation for converting them to CD. The DJ mixer will most likely have line level inputs as well, so you could connect a cassette deck or other line level source to the mixer.

Another option is a small inexpensive microphone and line level mixer. Note that these mixers do not usually include inputs for turntables.

When purchasing a mixer make sure to also buy a microphone that is compatible with the mixer. Unless you are sure of what you are doing it is probably best to visit your local music store. Don’t let them sell you a $1000 DJ mixer and $500 microphone – unless you are a professional DJ you don’t need equipment at that level.

The advantage of a mixer is that you can connect all your audio sources to the mixer then connect the mixer to your computer. No need to be constantly re-plugging things at the back of your computer.

To connect the mixer to your computer you will probably need a dual-RCA to stereo mini-plug cable like this one:

Photo of a dual-RCA to stereo mini-plug cable.
Dual-RCA to mini-plug cable

Plug the RCA plugs into the RCA output jacks on the back of the mixer. Plug the stereo mini-plug into the line input port on your computer. There are also mixers that can be connected to the computer via USB and do not require the stereo mini-plug cable.

If you do buy a mixer, you will no longer be connecting the microphone directly to your computer. See Connecting a Mixer.

Tutorial – Connecting an Instrument

Generally speaking you will want to connect these instruments to the line input port on your computer, not the microphone port (which is often mono). Not all computers will have a line input port.

  • Some PC laptops may have a hardware or software switch to convert the microphone port to line-level stereo.
  • Some PC notebooks/netbooks may have a compliant microphone input port which will tolerate line level inputs and may provide stereo input.

Always try line-level input first, and only use a microphone input if you cannot otherwise get adequate recording volume. You can buy modestly priced, decent quality USB interfaces with line level stereo input if needs be.

Connecting a keyboard to your computer

If the keyboard has RCA jacks on the back then the best way to connect it is with a dual RCA to stereo mini-plug cable as shown below, plugged from the RCA output jacks on the back of the keyboard to the line input port of the computer.

image of RCA to quarter-inch adapter
A Stereo Mini plug to dual RCA cable

If the keyboard has two 1/4 inch jacks on the back you will need a 2 x 1/4 inch jack to stereo 3.5mm jack, or you could use a dual RCA to stereo mini-plug cable, and two RCA to 1/4 inch adapters. Plug the RCA plugs into the RCA jacks on the adapters – you now have a dual 1/4 inch to stereo mini-plug cable.

image of quarter-inch to 3.5mm cable image of RCA to quarter-inch adapter
1/4 inch jack to stereo 3.5mm jack An RCA to 1/4 inch adapter

 

If the keyboard has neither of these options, but does have a 1/4 inch or 3.5mm stereo headphone jack, the easiest way to connect it is with a cable with a stereo mini-plug on one end (for the computer), and an stereo jack plug of appropriate size at the other end for the keyboard headphone socket. Plug the headphone output of the keyboard to the line input port of the computer. You will lose the ability to listen directly to the keyboard using headphones, and any internal speakers will probably be muted. You can get around this using a headphone splitter cable, or by enabling Software Playthrough in Audacity, (Software Playthrough will introduce a delay between the time you play a note and the time you hear it). This topic is covered in more detail in a following section.

Connecting a guitar to your computer

This section is about connecting an electric guitar, bass guitar or acoustic guitar with electrical pickup to your computer. If you want to record an acoustic guitar with a microphone, or record the sound of your guitar amplifier using a microphone, please read the section on connecting a microphone to your computer.
If you have a “USB Guitar” then you can skip ahead to testing the input connection for your operating system.

Generally the output level from an electric guitar (or electrical pickup in an acoustic guitar) is sufficient to drive the line input port on a computer. Turn the volume control on the guitar all the way up. You will need a shielded adapter cable that goes from a 1/4 inch mono plug (to plug into the guitar) to a mono mini-plug (to plug into the computer line input port).

You probably have a guitar cable for plugging the guitar into an amplifier, and you may be tempted to buy a 1/4 inch to 1/8 inch adapter instead, plug it into the computer line input then connect the guitar to the adapter using the cable – don’t do this! This creates a heavy, stiff cable hanging off the back of your computer – the slightest tug in the wrong direction could damage your sound card!

If you cannot get a good recording level when connecting to the line input port (explained in a following section on setting recording levels in Audacity), you can try the microphone input on your computer (if you have one). Beware of overloading the microphone input. You can turn down the volume control on your guitar to compensate for the extra amplification in the microphone input port, but hum and noise may increase in comparison to using the line input port.

Most effect pedals are designed to deliver about the same volume to the amplifier as the unaffected guitar sound (the volume you get when the effect is bypassed). Thus you can connect your guitar to a pedal and then connect the pedal to the computer.

Some guitar amplifiers include a “direct output” for feeding the amplifier sound to recording or PA systems. Amplifiers designed for stage use that include this feature will usually have either a line-level 1/4 inch mono jack output, or a microphone-level balanced output using an XLR connector. Connecting this output to your computer microphone input is beyond the scope of this Tutorial – talk to the folks at your local music store.

Some amplifiers have a 1/4 inch output for connecting an external speaker. This must not be connected directly to the computer sound card input as the signal level is far too high and may permanently damage the sound card.

Some USB audio interfaces are specifically designed for connecting a guitar to a computer or may have a dedicated input for electric guitar or bass guitar. Talk to the folks at your local music store.

Tutorial – Connecting a Mixer

To connect a mixer to the line input port on your computer you will need a dual-RCA to mini-plug (1/8 inch) cable. Plug the RCA plugs into the RCA output jacks on the back of the mixer. Plug the stereo mini-plug into the line input port on your computer.

Back of mixer showing output connection

If you don’t have a line input port (many Windows laptops don’t), you’ll need a line level USB audio interface. In that case you will need a cable that connects from the output of the mixer to the input of the USB interface. In the illustration below a dual-RCA cable is connected from the output of the mixer (out of frame) to a USB interface. The USB interface then plugs into the USB port on the laptop.

UCA202 connected to a laptop