Part 2: Speakers and Amps In Part 1 of this post we discussed how magnets are used in guitar pickups to bring the sounds of rock alive. In part 2 we’re going to talk about how magnets are involved in the other end of the experience: hearing the music. Whether you’re listening to live rock or jamming out to your favorite album at home, magnets are involved. Amplifiers and speakers use magnets to catch vibrations by musical tones. These sounds are then magnified, allowing you to rock out. But how does it really work?
  1. Turn Up the Juice--Just like guitar pickups, the whole process require electricity. In terms of your speakers, music is processed through an amplifier or receiver and sent through electromagnetic coils, or voice coils, to the speaker. Once it arrives at the speaker, the varying magnetic field given off by the voice coils which meets a magnet with a fixed magnetic field in the body of the speaker. This causes the voice coil to vibrate again a diaphragm, thus producing amplified sound. For a more detailed explanation, click here.
  1. We’re Gonna Need a Bigger Magnet--Stereo speakers typically come in three different sizes: tweeters, woofers, and subwoofers. As you may have guessed, tweeters (named for the high-pitched sounds birds make) handle the higher frequencies while woofers (named for the tones of dog) handle the lower ones. The subwoofer handles the deep bass. The length of a sound wave determines its pitch. The shorter the wave, the higher the pitch. The longer the wave, the shorter the pitch. It stands to reason that longer pitches require larger magnets. This is what makes subwoofers and amps so heavy.
  1. Wall of Sound--It the world of rock music, a guitarist's’ sound is carried from the pickups, through a cable right into the amplifier. The current can also run through any number of effects pedals to further manipulate the sound. One the sound is to the guitarist’s liking, it is finally allowed to reach the cabinet, or cab. This is essentially just musician talk for really big speaker. Amplifiers and cabinets both have wattage capacity. The higher this capacity, the louder the music. Of course, serious rockers go for an entire wall of cabs.
Whether it’s a wall of amps at a rock concert, a home surround system, the speakers in your car, or even some headphones, magnets are vital to the amplification of sound. As music made its big jump from acoustic to electric, getting louder and louder, bigger and bigger magnets were needed to handle the demand. Do you have a favorite amp or speaker? What do you love about it?