How does an electric guitar pick up only sounds from the strings and not speech for an example?

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Edit: Thanks for all the answers <3

In: Technology

9 Answers

Anonymous 0 Comments

A guitar does pick up sounds from the environment, just very specific ones.

If you move a piece of wire near a magnet, an electric current is made in the wire. The size of the current is also determined by the size of the motion.

So you are correct in assuming that guitar and mike both have principlly the same thing.

However in the guitar the wire that moves is the guitar string and in the audio mike, the movement is made by a disk that is really sensitive to movements made by human voice (or whatever range of sound you wish to pick up)

So in order for the guitar to pick up sounds the guitar string has to be made to vibrate by something other than the players fingers.

This can be done through resonance, the same way an opera singer can break a glass by singing the frequency that the glass vibrates at.

If there is a sound in the environment, at the frequency that the string vibrates at, then the pickups will capture it and send it to the amp.

You have heard this sound, you call it feedback

Put a guitar in front of the output speaker and pluck a note, that vibration gets picked up, amplified and played out the speaker, the speaker makes the string vibrate and the sound is picked up and amplified again.

Anonymous 0 Comments

It doesn’t. An electric guitar has magnetic sensors that detect how the strings are moving, by detecting disturbances in a magentic field under the string.

Anonymous 0 Comments

They are designed to amp up sounds that are very near to the mic, and to quiet down sounds that are further away. They’re basically the opposite of a panoramic mic.

Anonymous 0 Comments

An electric guitar pickup is essentially thousands of turns of thin copper wire wound around a magnet. When a steel string vibrates near the pickup, it will disturb the magnetic field. This induces a small electric current in the copper wire, which is then amplified.

An electric guitar needs steel strings to work. Nylon strings will not work on an electric guitar.

Speech is just pressure changes in air, creating no disturbance in the magnetic field, so it will not be picked up. However, if a speaker (in a toy laser gun for example) is brought near the pickup, the guitar will pick up the signal because the speaker itself works using electromagnetism.

Anonymous 0 Comments

In a normal microphone there is a diaphram which gets moved by the changes in air pressure and then the electromechanic components of the different types of microphones will record the movement of the diaphram. However in an electric guitar there is no diaphram but the pickup is detecting the movements of the strings directly. As the strings of a guitar is quite narrow and are strung quite taught they do not really pick up much vibration from the changing air pressure from the sound of your voice or other instruments. This way the guitar pickup is only picking up the sounds from the strings.

Anonymous 0 Comments

The real question to me is, how DO they still pick up your voice if you yell into it? If you have a lot of gain and turn it up, you will hear the voice, and it’ll do it with the strings muted directly over the pickups so they aren’t vibrating.

Anonymous 0 Comments

Put your phone speaker right up to the pick-ups on top of the strings, you’ll be able to hear what is being played

Anonymous 0 Comments

A guitar pickup is not a microphone. It detects changes in the magnetic field around it due to a vibrating steel string nearby.

Pickups are a coil of wire wrapped around magnets. If the wire is loose then it can itself vibrate when the guitar is tapped or a loud noise is made near to it. When the wire vibrates it sees changes in the magnetic field and therefore generates a signal.

This is not desirable behaviour from a pickup so they are often potted with wax to stop the coils vibrating

Anonymous 0 Comments

A normal microphone works by having a very thin membrane attached to a small magnetic coil – a sound nearby will cause the membrane to vibrate, which creates a small electrical current that we can then use as the input to equipment like recorders or amplifiers.

A guitar pickup however works in a slightly different fashion – rather than using a membrane attached to a magnetic coil to create the current, a pickup makes use of the fact that electric guitars are strung with steel strings, and these vibrating will create a voltage in a magnetic coil.
This means the pickup in an electric guitar will only detect the vibration of those steel strings, not other noise nearby – so in a loud place (such as on a stage) the pickup only detects the guitar and won’t get overpowered by the volume coming from other instruments, speakers or other things.

There are some flaws to the guitar pickup – the first is that they have a very distinctive sound. So while an acoustic instrument will sound essentially the same played acoustically as it will when paired through a microphone and pa, the electric guitar is pretty much useless acoustically, and amped up creates a sound unlike any acoustic instrument that is really created by the amp sand any effects that are being used than the guitar itself.
The other one is that they are not impervious to outside interference, just much better than acoustic instruments – the squeal of feedback you hear is the result of placing the guitar somewhere the volume will start to vibrate the strings, which then gets amplified and vibrates the strings some more and creates as feedback loop. Also you can get interference from things like radio signals and electricity – the hum of an electric light for example can often be picked up by a guitar, and if you hit the right combination of gain stages, poor shielding sand atmospheric conditions, your fist can act like a giant antenna for radio broadcasts.