Acoustic Guitar Glossary
Guitar Terms Explained
Confused by some of the language used to describe acoustic guitars? We explain some of the more common technical terms below – but feel free to contact us if you can’t find the information you’re looking for here…
The plastic strip around the edge of the soundboard, disguising the join between the soundboard and the sides of the guitar, and protecting the corners from being damaged. Although plastic is stronger, some manufacturers prefer to use wood for a more traditional appearance.
Bound fingerboards are also common – in this case a plastic or wooden strip is fitted around the edge of the fingerboard to disguise the ends of the frets.
The strips of wood glued to the underside of the soundboard, which add strength, and help to transmit the vibration of the strings around the soundboard. The pattern of these struts varies between the different manufacturers, and is part of what helps to give each make and model of guitar its own unique sound.
The block of hardwood (usually rosewood or ebony) attached to the soundboard, that holds the saddle, and where the ends of the strings are held in by bridge pins.
The small plastic pins (sometimes wooden on more expensive instruments) that fix the ends of the strings into the bridge. Sometimes these are replaced with heavier brass bridge pins, which can help to increase a guitar’s sustain, improve its tone, and eliminate problems with wolf notes.
Commonly found on electro-acoustics, a cutaway makes it easier to reach the highest frets on the guitar, and play higher notes – particularly popular with guitarists who mainly play electric guitar, but want an acoustic as well. Some purists argue that acoustic guitars with a cutaway don’t sound as good. The acid test is to play it – if you like it, that’s all that matters!
Equalisation (EQ) Controls
Many guitars have EQ controls, which allow you to alter the sound going out of your guitar into an amplifier or PA system. The most common type is a 3-band EQ, with the familiar bass, middle and treble controls found on many home stereo systems.
Some guitars have a basic 2-band EQ with only bass and treble controls, and some have 4-band EQ with an extra “presence” control for the very highest frequencies.
Additional EQ controls found on some guitars include:
- Mid Sweep, Mid Frequency or AMF – this is an advanced EQ function which allows you to change the frequency that the Mid control is cutting or boosting.
- Scoop – an extra middle control that cuts out a slightly different range of frequencies.
- Presence – an extra EQ control that allows you to cut or boost the very highest frequencies (above the range of the treble controls).
- Enhancer or Exciter – adds extra high harmonics, making your guitar sound brighter.
- EQ Bypass switch – if you don’t want to use any of the EQ controls on your guitar, this switch takes the EQ out of the pre-amp’s circuit, giving you a slightly cleaner signal.
The piece of hardwood, directly below the strings, onto which the frets are mounted. Budget and mid-price instruments usually have a rosewood fingerboard, while more expensive instruments normally use ebony (a denser, harder wearing timber).
Decoration added to the soundboard, fingerboard and sometimes the headstock of the guitar. Usually made from abalone, although plastic and wood are also used. Inlays are normally placed on the 3rd, 5th, 7th, 9th and 12th frets to make it easier for players to find and remember where the notes are.
A soundboard (top) that’s made from several layers of wood stuck together – see our article on laminated vs solid tops for more information.
Placed on the headstock, and used to tune the strings. Almost all guitars over £150 are fitted with die-cast machine heads, which are sealed to prevent dirt and rust getting into the workings, and filled with oil so that they are constantly lubricated. Some cheaper guitars have machine heads that are covered (but not sealed) or even completely open (though this is rare on new instruments).
Some high-end acoustic guitars (eg Collings and some Martin models) that are copies of vintage instruments from the 1930s and 40s, use completely open-backed “Kluson-style” machine heads. These are obviously much better quality than the open-backed machine heads found on cheaper instruments, but they may still need to be cleaned out from time to time if dust and dirt get into the workings.
Sometimes a gear ratio is given for machine heads – eg 18:1, meaning that for every 18 turns of the machine head, the post holding the string turns round once. In theory, larger gear ratios make it easier to tune more accurately, although they also mean it takes longer to wind a string on when changing strings. In practice, as long your guitar has good quality machine heads, it should be relatively easy to tune up whatever their gear ratio is.
This control on a preamp allows you to cut out a very narrow frequency range (without affecting the frequencies immediately above or below) to prevent feedback at that frequency. The exact controls vary from guitar to guitar, but most have an on/off (or in/out) switch, some allow you to control the frequency that is being cut out (otherwise the filter is permanently tuned in to the frequency that’s most likely to cause problems), some allow you to control the amount that the frequency is being cut by.
The small white block between the fingerboard and the headstock, which holds the strings in place. Usually made from plastic or composite materials, but sometimes a repairer will make a replacement out of bone.
Some pickups have a phase switch. This is only really useful if you are using a combining the sound of your pickup with the sound of your guitar played through a microphone. Depending on the position of the microphone, if the signals coming out of the microphone and the pickup are “out of phase” they can cancel each other out, causing the guitar to sound “thin” and quieter than it should. The phase switch literally turns the soundwave coming out of your pickup upside down, so they are back “in phase”.
There are four main types of pickup used on acoustic guitars:
- Under-Saddle Transducers – The most common type of acoustic guitar pickup – a narrow piezo-electric strip that fits underneath the saddle, picking up its vibrations. Almost all guitars that are built as electro-acoustics will have this type of pickup fitted to them (some may also have an internal microphone). Almost invisible once fitted, a good quality under-saddle transducer such as our favourite, the Fishman Matrix, makes a powerful, punchy sound and tends to be good at rejecting feedback, making them popular with gigging musicians.
- Magnetic Soundhole pickups – These pickups fit across the soundhole of your guitar, usually with some kind of clamp mechanism, and they work in the same way as an electric guitar pickup by using magnet(s) to pick up the vibration of the strings. The best feature of these pickups is that they don’t have to be fitted professionally, and they can be removed again without making any alterations to your guitar (although some can be installed permanently if you prefer).Unfortunately the cheaper soundhole pickups tend to pick up a lot of hum from electrical equipment (particularly computer monitors and spotlights) so if you intend to use a soundhole pickup for gigging and/or home recording, it’s best to go for a humbucker pickup such as the Fishman Rare Earth Humbucker. Sound-wise they tend be a bit more “delicate” or “transparent” than an undersaddle pickup.
- Internal Microphones – Small, internally-mounted condenser microphones produce a sound that’s arguably more “natural” than any other type of pickup, although they tend to suffer from the most problems with feedback. For this reason, internal microphones are usually fitted alongside an under-saddle pickup and an on-board “blend” control, so if you find yourself suffering from feedback problems, you can turn down down the microphone and turn up the under-saddle pickup.If your guitar suffers from feedback problems, you could try using a Feedback Buster.
- Soundboard Transducers – These pickups have a small flat pad that sticks directly on to the soundboard of the guitar (either outside or inside). Soundboard transducers can be quite difficult to fit properly – it usually requires a lot of trial-and-error to find the best position for the pickup element, otherwise they can sound very “boomy” on certain notes, and suffer badly from feedback problems.The new Taylor Expression System uses an advanced form of soundboard transducer – two of them, in fact – in conjunction with a magnetic pickup hidden under the soundboard. In this case there’s no need to worry about finding the right place to stick the pickup, since Taylor have already done it for you!
Pickups can either be active or passive – active pickups have a small, battery-operated preamp that boosts the signal going out to an amplifier or PA system, this usually gives a much better signal to noise ratio (ie less background hum and hiss) particularly in the higher frequency range. Passive pickups don’t have a preamp, and generally have a much lower output level.
A small device, built into most electro-acoustic guitars, that boosts the signal coming out of the guitar, through the lead, and into an amplifier or PA system. Because the level of the signal is much higher, it suffers less from problems with electrical noise and interference (there is a higher “signal-to-noise ratio”), and less high frequency sound is lost as it travels between the guitar and the amplifier, so the tone is brighter, with more “presence”.
On purpose-built electro-acoustics, the pre-amp usually has a control panel which allows you to make changes to the way your guitar sounds. This usually includes controls for volume and EQ – other controls may include presence, scoop, mid-sweep, notch filter, mute switch, phase switch, EQ bypass switch, and a battery check button. Many preamps now also come with built-in electronic tuners, and some manufacturers have even experimented with adding built-in effects such as reverb and echo, although using these tend to seriously reduce the preamp’s battery life.
The narrow white block that fits into the guitar’s bridge underneath the ends of the strings, raising them to the correct height. Usually made from plastic or composite materials, although often repairers will make a replacement out of bone.
Many guitars now come with a compensated saddle, these have a ridge that alternates between the front and back edge of the saddle, allowing for the difference in string tension between the plain and wound strings, and thus improving the intonation.
The average sounding length of the strings (ie the length of the part that vibrates). To help the guitar’s intonation, and because the strings are not all at the same tension, the saddle is angled so that the bass strings are slightly longer than the treble strings – for this reason, the scale length is usually measured as the distance between the edge of the nut and the centre of the 12th fret, multiplied by 2.
A soundboard (top) that’s made from a single thickness of wood – see our article on laminated vs solid tops for more information.
The piece of wood (usually spruce or cedar) that forms the front of the guitar’s body. Also known as the guitar’s “Top”.
The hole in the centre of the soundboard that allows the sound to travel out of the guitar.
The woods used in the construction of the guitar, specifically the parts that most affect the sound or tone that the guitar produces (i.e. the top, back and sides of the body). See our list of tonewoods below for information on the different timbers that are used.
A long metal rod that’s built into the neck behind the fingerboard to counterbalance the tension of the strings.
Loosening the truss rod increases the curvature of the neck, tightening it makes the neck straighter. When set correctly, the neck should have a very slight concave curve to it
See machine heads.
- Upper Bout – the upper bulge in the guitar’s body
- Lower Bout – the lower bulge in the guitar’s body (almost always the larger of the two)
- Scale Length – the average sounding length of the strings (to help the guitar’s intonation, the saddle is angled so that the bass strings are slightly longer than the treble strings – the scale length is usually measured as the distance between the nut and the centre of the 12th fret, multiplied by 2)
- Body Length – the length of the body section of the guitar, not including the heelblock
- Body Depth – the depth of the body (measured at its deepest point)
- Total Length – the length of the entire instrument
- Nut Width or Fingerboard Width At Nut – the width across the end of the fingerboard where it meets the nut
- String Spacing at Nut – the distance between the 1st and 6th strings at the nut
- String Spacing at Bridge – the distance between the 1st and 6th strings at the bridge, measured at a right angle to the strings.
- Saddle Width – the width of the saddle. With steel string guitars this is normally either 3.2mm (wide) or 2.3mm (narrow)
- String Action – the height of the strings above the 12th fret.
Each of the woods used in the construction of acoustic guitars has its own unique tonal properties and appearance, illustrated in the table below:
|Sitka Spruce||Top||The hardest of the woods used in the manufacture of soundboards, Sitka spruce produces a loud, bright tone, accentuating the basses and trebles.|
|Engelmann Spruce||Top||A lighter coloured wood than Sitka spruce, the tone is louder, remaining bright but with a slightly more refined quality.|
|Cedar||Top||A softer wood than spruce, which produces a warm, mellow, ‘earthy’ tone. Used for many years on the soundboards of classical guitars, but recently becoming popular with steel string players too.|
|Mahogany||Back / Sides||Mahogany is a hard, bright sounding wood with a tendency to accentuate the mid-range. With its large dynamic range, it responds very well to both sensitive playing and louder, percussive styles.|
|Indian Rosewood||Back / Sides||With a dark red / purple tinted hue, and an unmistakable regular grain pattern of dark and light stripes, rosewood is famous for its rich basses and clear treble response. One of the most popular woods for constructing guitar bodies.|
|Brazilian Rosewood||Back / Sides||The most sought after tonewood used in guitar making, revered for its deep basses, mature mid-range and balanced trebles. Now in increasingly short supply, reserves of Brazilian Rosewood are generally reserved for the highest spec models.|
|Maple||Back / Sides||Available with either a ‘flamed’ or a ‘quilted’ figuring, maple has a very light colouration, and produces a sound with a very fast attack, particularly suiting faster, percussive styles of play. Tonally, maple tends to enhance the mid-range and trebles, and is best combined with a spruce top.|
|Koa||Back / Sides||Koa originates in Hawaii, and is a beautifully figured wood, dark brown in appearance with a pronounced, wide grain pattern and occasional blonde streaks. Tonally it combines the clear voicing of maple with deeper, rosewood-like qualities, and a sensitivity more usually associated with mahogany.|
|Walnut||Back / Sides||With its unique ‘marbled’ appearance and a wide variation of hue and figuring, walnut looks especially striking on the bodies of acoustic guitars. Tonally it produces a warm sound, with plenty of bass, and combines well with either a cedar or spruce top.|
|Dao||Back / Sides||A chinese wood, with a deep brown colouration and a remarkably straight grain. Produces a warm tone with plenty of bass and midrange.|
|Bubinga||Back / Sides||Often referred to as ‘african rosewood’, and shares many of rosewood’s tonal properties, but is lighter in colour, often featuring a beautiful swirling grain pattern.|
|Myrtle||Back / Sides||Similar to flamed maple in both tone and pattern, although it has a deeper, olive hue.|
|Australian Blackwood||Back / Sides||An unusual timber, similar in appearance to Koa with its slightly wavy grain, but with tonal properties more akin to those of mahogany, being bright sounding and rich in the mid range.|
|Amazaque||Back / Sides||A multi-coloured wood with tints of red, green and brown, tonally somewhere between rosewood and maple, combining the rich bass of the former with the latter’s punch and precision.|
|Wild Cherry||Back / Sides||A renewable hardwood used to construct the Back & Sides of most Seagull and Simon & Patrick guitars. Wild cherry has a mid-brown colouration, with a wide, swirly grain. Tonally it tends to accentuate the mid-ranges and trebles.|
|Sapele||Back / Sides||A mahogany-type wood, with a “ribboned” texture to the grain, and a harder, denser composition than genuine mahogany. Sapele is a very bright, lively sounding wood that produces clear, sparkling trebles.|
|Ovangkol||Back / Sides||Similar in appearance to rosewood, but with a lighter, coffee-coloured hue. Ovangkol shares many of rosewood’s tonal characteristics, with a slightly livelier mid-range and a little less in the bass register.|
|Sycamore||Back / Sides||Another wood with a fast attack and decay, Sycamore has been used in the manufacture of Spanish flamenco guitars for many years, and is starting to find favour with steel-strung players as an authentic but inexpensive alternative to Maple|
|Nato||Back / Sides||Nato is an inexpensive substite for mahogany, sharing the latter’s bright, pronounced mid-range, although it arguably lacks a little of the sensitivity and ‘punch’ of the genuine article.|
|Agathis||Back / Sides||A low-cost alternative to Maple, with a fast attack and decay, and a balanced sound from bass to treble.|
|Meranti||Back / Sides||A low cost timber favoured more for its stability and structural strength than tonal properties. Allows factories to build low cost guitars that work properly, even if their tone isn’t that spectacular!|