Lifestyle | 1 September 2016The Anatomy and Acoustics of the Stratocaster Share article facebook twitter google pinterest Whether you’ve owned a Strat for years or you’re setting out to purchase your first, The Stratocaster Manual: Buying, Maintaining, Repairing, and Customizing Your Fender and Squire Stratocaster has something to offer. The manual is replete with interesting facts and contextual information; practical instructions pertaining to tuning, storing, cleaning and transporting your guitar; and cool ideas for customizing the look of your instrument. Because Fender and Squier models are constructed identically, Burrows’ manual can be applied to either brand. Familiarize yourself with the anatomy of the Stratocaster, then read on to learn about the physics and acoustic properties that do all the work while you’re “playing.” Anatomy of a Stratocaster While there may be small variations between different models, the exploded view shown here shows the basic make-up of a Stratocaster—which remains pretty much the same as when it first appeared in 1954. In fact there is a surprisingly small number of components—less than 160 in all—that combine to make up a Fender Stratocaster. Photographed for the Orgone Company by Paul Smith © Photographed for the Orgone Company by Paul Smith © How Your Stratocaster Works Electric guitars are essentially simple pieces of technology. Over the next few pages we’ll take a look at some of the underlying scientific principles behind the way a Stratocaster—or any other electric guitar— works. Don’t worry, it’s nothing too taxing! First Principles The heritage of all stringed instruments can be traced back to the musical bow, pictorial evidence of which has been found in cave paintings in France dating back more than fifteen thousand years. Similar in design to a hunting bow, it featured a string made from animal intestines stretched tightly between the ends of a curved piece of wood, cut from the branch of a tree. The string would have been plucked by the fingers or struck with a piece of wood or stone. By holding down the string along the length of the bow, different pitches could be played. This is the basic principle governing the way all guitars work. Variations on the musical bow are still widely used in traditional music across the globe. Photo Credit © Ahmed Ali. Audio Frequencies Whenever a tightened string is struck, the specific pitch of the note you hear is determined by the frequency at which it vibrates. This is known as the note’s fundamental. If you shorten the length of that string, or increase the tension, the frequency will be increased, raising the pitch of the note. Conversely, if the string is lengthened or slackened, the frequency/pitch of the note you hear will be lowered. (This rule for waves can be expressed as v = lf where “v” is the speed, “l” (lambda) is the wavelength, and “f” is the frequency.) In the West, we have a specific relationship between these frequencies and the names we give to the notes from A to G, which is referred to as Concert Pitch. This defines the note A below Middle C (sometimes called “Middle A” or “A4”) as a frequency of 440 hertz (Hz)—in other words, a vibration of 440 times per second. If we look at the following two sets of sine waves, which give a visual representation of two vibrating strings when measured with an oscilloscope, we can further see the nature of the relationship between frequencies and pitch: Let’s say that Wave A shows “Middle A”—a frequency of 440 Hz. Wave B shows exactly twice as many peaks and troughs, meaning that it vibrates at twice the frequency (880 Hz). This creates a pitch exactly one octave higher (A5). The vertical axes show amplitude (loudness) of the wave. All of the diatonic notes within an octave, that’s every half-step—or for each guitar string, every note played on every fret from the open string up to the 12th fret—will have a specific mathematical relationship with one another. The table on the right shows the frequency of every note on every fret of the A string (the fifth string from the top) on any correctly tuned guitar: as you can see, the A on the 12th fret (A3) is double the frequency of open A (A2). Hearing the Sound So when you make a string vibrate, why do you hear a sound? All sounds reach us through the displacement of air between the source of the sound and our ears. When the string is plucked it disturbs the surrounding air, causing the displacement of molecules. This causes adjacent molecules to be disturbed until the energy created by the initial displacement has dissipated—the energy eventually decays to zero, losing a small amount as it is transferred between each molecule. We perceive this energy as volume. So the reason why a musical bow can only be heard from close proximity is that it can only displace a small amount of the surrounding air. To make a string displace more molecules it would need to be connected to some kind of soundboard, a larger object that also vibrates when the string is plucked. (You can hear this effect by comparing the volume of an elastic band being twanged between two fingers and when one end is held against a resonating surface like a wooden table.) Acoustic guitars achieve this volume enhancement using a sound chamber, which takes the form of the hollow wooden body. The string vibrates between the nut and the bridge saddle which causes the sound chamber to vibrate, disturbing the air molecules inside the body. Since the whole of the guitar vibrates to a greater or lesser degree, this is how the specific properties of different types of wood can affect the sound—different timbers, for example, absorbing different frequencies—or, indeed, different types of construction. Magnetic Disturbance The Fender Stratocaster, of course, has no resonant cavity, but has a body made from a slab of wood, and so doesn’t vibrate to anything like the same degree—this is, after all, the whole point of the solidbody electric guitar. So for it to be heard it must be amplified electronically. And the best way to do that is to use a magnetic pickup. Although the principles of electromagnetism had been known since the 1830s, it was not until the beginning of the twentieth century that the first audio amplification was developed. Engineer Lloyd Loar is widely credited as having pioneered the concept of the magnetic pickup in 1924 while working for Gibson, but it wasn’t until the following decade that such an idea would be commercially applied to a guitar. A magnetic pickup is a very simple device, comprising a set of small magnets (or one large bar magnet) wrapped up many thousands of times by a coil of fine copper wire. (A pickup is, in fact, quite straightforward for anyone to build.) This describes a single-coil pickup, the type found on Fender Stratocasters. The two ends of the copper wire are connected to the output socket of the guitar—usually via a simple volume and tone circuit—which is then connected via a screened cable to an amplifier and loudspeaker. To return to some elementary physics, a magnetic pickup functions according to Michael Faraday’s Law of Induction, which looks at the way disturbances applied to a magnetic field can cause current to flow in wires; in other words, how changing a magnetic field creates voltage. The pickup is positioned directly beneath the strings of the guitar. To have any impact on the pickups, these strings must be made from a ferromagnetic material, such as nickel or steel—that is, they must be attracted to magnets. When the strings are struck the vibration disturbs the magnetic field, inducing an alternating current that runs through the coil of copper wire and is passed along through the amplifier and made audible by the loudspeaker. Photo Credit © Outline Press Ltd. Pickup Positioning Although the Stratocaster features three similar single-coil pickups, you will notice that they all have different tonal characteristics. Why is this? To give a satisfactory answer we need to look more closely at the behavior of strings as they vibrate. If we take a practical example of a string vibrating between two points—the nut and the bridge saddle—the pitch of the note we perceive is the fundamental. However, the sound is a combination of a number of other waves called harmonic modes, and these vibrate at equal divisions of the fundamental at increasingly higher frequencies. In fact, the fundamental can also be termed the first harmonic; the second harmonic, divides the fundamental by two; the third harmonic by three, and so forth. This can best be illustrated by looking at a standing wave pattern, which shows the way in which waves move, and their points of minimum and maximum movement. The black dots represent the minimum movement—the points at which the string does not move at all—and are called nodes; the red dots show the point of maximum movement—the antinodes. In this example, even using only the first four harmonics, you can already see that the composition is very different at the points along the string at which pickups A and B are positioned—the second and fourth harmonics are not vibrating at all above pickup A. This is, of course, a very artificial example, made to illustrate the complex makeup of a vibrating string and the way the tone changes at different points along the string according to the alignment of nodes and antinodes. When it comes to pickup placement, as a general rule, we can say that the closer the pickup is positioned to the antinode of the first harmonic, the warmer the sound will be; the closer it is to the node of the first harmonic, the brighter the sound will be—and this is the classic difference between the sound produced by the bridge and neck pickups. It’s more than likely that, after experimentation, Leo Fender and his colleagues positioned the pickups on the Stratocaster where they created the most pleasing tone. Yet if we look at their placement in tandem with the string harmonics, we see some interesting things happening. The neck pickup is positioned directly beneath the node of the fourth harmonic, meaning that fourth harmonic does not sound at all when only that pickup is selected. Furthermore, when the bridge and middle pickup are selected together, each plays the fifth harmonic at the same point but out of phase with the other. Of course, Fender deliberately slanted the bridge pickup so that the sound from the lower strings came from a point further away from the node, thus creating a warmer bass end. All of these factors contribute to the unique sound of the Fender Stratocaster. Buy from an Online Retailer US: UK: This is the ultimate owner’s manual for the world’s most popular guitar! This is a step-by-step, heavily illustrated guide to everything about the legendary Fender electric guitar, the Stratocaster! It shows owners and dreamers the basics of selecting and buying Strats; maintenance and repairs such as tuning, setting intonation, tremolo alignment, fret repairs, and bridge and nut adjustments; electrical troubleshooting; spur-of-the-moment stage-side fixes; and some basic “performance” enhancements such as adding “hot rod” Fender and aftermarket pickups, locking-tremolo nuts, and more. Let world-renowned guitar expert Terry Burrows be your guide to this awesome instrument. Gorgeous shots of Fender guitars and guitar parts and images of well-known musicians playing Stratocasters make this a book no fan will want to miss. Share article facebook twitter google pinterest If you have any comments on this article please contact us or get in touch via social media.