Piano principles Recording Real Pianos

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Piano principles Recording Real Pianos HUGH ROBJOHNS The essence of recording a musical instrument is to capture the most faithful possible rendition of the performance without distorting the tonal quality of the instrument or veiling it behind undesirable mechanical noises. Every piano presents its own unique set of problems and solutions and in this workshop I shall be suggesting some practical techniques to provide a starting point. The key to recording any musical instrument is to position the microphone in the optimal place and this task is much easier with an understanding of how the instrument works, where the sound comes...

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Piano principles Recording Real Pianos HUGH ROBJOHNS The essence of recording a musical instrument is to capture the most faithful possible rendition of the performance without distorting the tonal quality of the instrument or veiling it behind undesirable mechanical noises. Every piano pres- ents its own unique set of problems and solutions and in this workshop I shall be suggesting some practical techniques to provide a starting point. The key to recording any musical instrument is to position the microphone in the optimal place and this task is much easier with an understanding of how the instrument works, where the sound comes from, how it radiates from the instrument, and what its frequency and dynamic range is. So, as with all of my workshops to date, I will start with a brief review of the piano to get a feel of what is involved; for some background information on the development and design of the piano, see the ‘A Little History’ box. “Miking a piano is never easy; I have found it to be the most Sound Creation & Radiation frustrating, yet rewarding instrument to work with.” The fundamental of any vibrating piano string tends to be the strongest component in its sound, although the higher harmon- ics are at least equally strong in the lowest two octaves due to the restricted physical size of the soundboard. At the lowest note (27.5Hz) the fundamental can be as much as 25dB below its strongest harmonics, though this is dependent on the design of the piano. At the upper end, the highest fundamental is around 4100Hz, with harmonics extending beyond 10kHz, although these tend to be relatively weak. The ﬁrst partial above the top C is typically 20dB below its fundamental, producing an almost sinu- soidal sound wave at these upper reaches. Much of the character of a piano stems from the range of harmonics it produces (many of which are not straightforwardly relat- ed to the fundamental) and noise components which are percussive in nature. The mechanical noises are primarily between 200 and 500Hz for the lower notes, centre around 200Hz for the middle of the instrument’s compass, and peak at about 1kHz for the upper regions. This last peak is typically below the fundamental of the notes and so is not masked as effectively as for the lower and middle regions, becoming more obvious to the ear as a consequence. These artefacts, as well as the harmonic components generated by a struck string, are all affected by the hardness and density of the felt on the hammers, as well as the dynamic ener- gy with which the string is struck. Perhaps surprisingly, the overtones of struck piano strings do not adhere to a strict harmonic frequency relationship because of the percussive nature of their resonance (compared to a continually stimulated stringed instrument), and tend to be slightly high- er than the maths would predict. This phenomenon is particularly obvious in the higher registers of smaller pianos where the  strings are stiffer than normal due to their required strength and shortness, and results in a less pure and sonorous sound quality. With the dampers lifted, a piano will resonate for over 10 seconds in the middle registers and over 40 seconds in the bass strings, although the balance of decay times is very dependent on the construction.The top C may last around 3 seconds and the same spread of decay times is apparent within the harmonic series of a single note, with the fundamental or ﬁrst partial lasting far longer than the upper harmonics. The dynamic range of a piano, measured at the rather distant reach of 10 metres, varies between about 85dBC and 70dBC for the loudest playing (the upper notes being weaker than the bass notes). At the quiet end of the scale, bass notes rest around 50dBC, with mid and upper notes falling to 37dBC. The radiation of sound from a grand piano is determined fundamentally by its soundboard, but is complicated by reﬂections from the ﬂoor, lid and ceiling. The body of the instrument, as well as the lid, also signiﬁcantly affects the radiation pattern towards the middle and upper frequencies. Further complications arise from the fact that the vibrations within the soundboard are not only shaped by the frequency of the vibrating string, but also its position on the soundboard. No wonder the instrument is so hard to record! In the lower registers, the sound radiation is largely symmetrical, although at 250Hz the sound level is about 5dB higher behind the piano (to the player’s left) compared to the front, because the interference of the lid causes some cancellation of these frequencies which are generated out of phase at opposite ends of the soundboard. Consequently, when standing behind the piano these lower frequencies usually seem to localise below the instrument. The main energy lobe in the horizontal plane is directed forwards over a 60 degree angle to the player’s right. At middle frequencies, the open lid starts to reﬂect sounds out of the instrument with greater directivity (the long support typ- ically angles the lid at about 38 degrees), with the best projection being forwards (to the right from a player’s point of view), and upwards — typically between horizontal and 55 degrees up. The timbre from directly above the piano is relatively dull due to the HF screening caused by the lid. In the horizontal plane the middle registers are radiated pretty symmetrically, although the rear bottom quarter of the instrument suffers from weakened fundamentals (up to 10dB down compared to the front).
The upper registers of the instrument are Second lobe much more strongly affected by the lid, with a strong directivity between 15 and 35 Ideal mic position degrees from the horizontal towards the front — the upper edge more or less follow- Main lobe ing the angle of the lid itself. Above and Small peaks in and troughs below these limits the upper harmonics can radiation to be as much as 10dB below the maximum rear found ‘on-axis’. In the horizontal plane the 1 KHz main lobe is directed straight forward with a 2 KHz second lobe about 30 degrees towards the bottom end of the instrument. These lobes 4 KHz are only about 10 degrees wide for the high- est frequencies, so to capture the true bril- liance of the instrument a microphone must be placed within a relatively narrow ‘sweet spot’. The mechanical noise components of the instruments do not radiate in the same way as the musical sounds, and tend to be much stronger, relative to the wanted string sounds, behind the piano than in front. Not a good idea to mic a piano from behind then! The changes to the sound radiation when the piano lid is closed are fairly obvious. The sound becomes duller as the high fre- quencies can not radiate as effectively, and the overall level decreases slightly. The radiation pattern loses its tendency to lobe upwards and towards the front, and a stronger lobe appears towards the player (principally through the opening behind the music stand). If the lid is half open, on the short stand, it sets an angle of about 10 degrees but, surprisingly, the radiation pattern is remarkably similar to the condition with the lid fully open. The principal radiation lobes are between 10 and 60 degrees again, although the maximum amplitude is less than with the lid fully open, particularly at the higher frequencies of course. The overall effect is of a slightly duller sound projection, without the full brilliance and clarity of which the instrument is capable. Taking the lid completely off the piano really messes up the radiation pattern, with a reduction in energy in the horizontal plane and a marked increase in the vertical plane. All obvious stuff really, and it results in the tone of the instrument becoming duller, although this is very dependent on the proximity and reﬂective characteristics of the ceiling, and the tone often also becomes thinner as there is a pronounced reduction in the low-frequency components. The main high-frequency directional lobe in the horizontal plane is out across the player’s right shoulder, about 60 degrees back from the main frontal axis, and upper-mid com- ponents (around 1kHz) are mainly directed behind the piano. Microphone Techniques Upright Pianos  Miking a piano is never easy; I have found it to be the The constricted physical nature of an upright piano makes life even harder most frustrating, yet rewarding instrument to work for the engineer than with grand pianos. However, we can immediately dis- card all the distant-mic techniques (see above) because the piano simply with. Needless to say, the room plays a very impor- does not radiate sound in an appropriate way. The easiest technique is to tant role, as does the position of the instrument with- open the top lid and mic from above with one or two mics as appropriate. in the room. Experiment with this aspect before you Positioning the mics inside the cavity provides greater isolation but tends to even plug a mic in, because if the instrument is setting sound coloured, particularly at the top end. Another good technique for off room resonances, the recorded sound will always isolation is to tape pressure-zone mics to the wall directly behind the sound- be poor. I will initially consider grand pianos, then board (remove the casework ﬁrst), or use a bespoke contact mic like the C- modify the techniques to suit uprights in the box Ducers. below. There is no one perfect technique for the A better solution is to remove the kick board at the front of the piano below piano and, like many instruments, different perform- the keyboard and use a pair of mics to pick up the bass and treble strings to ers can create totally different sounds from the same the right and left (respectively). Better still is to remove the back of the piano instrument in the same conditions, often requiring to reveal the soundboard, and use a pair of mics, one each side as before — all the positioning rules previously discussed still apply. This gives rather less totally different mic techniques to capture the best hammer noise and a better balance of sound to my ears, but make sure the sound. The suggestions below should only be taken piano is well away from walls — the soundboard should be facing into the as starting points, not complete solutions! room, not the wall! If there is sufﬁcient space, another technique is to put pressure-zone mics on the ﬂoor anything up to a metre away from the piano As with all instruments, the best sound is obtained at and slightly wider. It makes little difference whether in front or behind thea distance where the blend of acoustic elements from piano. the entire piano have combined into their composite form. However, because of the size of a grand piano (anything from ﬁve to nine feet long), this distance tends to be far greater than for any other instrument, putting rather more emphasis on the room acoustics and microphone technique. The required sound is a combination of all the constituent parts —
the hammers on the strings, direct radiation, sound emerging from the soundboard, reﬂections and guidance from the lid, and reﬂections from the ﬂoor and ceiling — and these sources are spread over a wide physical area, so very close miking is unlikely to be successful! In my experience, this kind of technique typically results in over-emphasis of a particular aspect of the piano sound, producing a coloured and unnatural result, although it is often the only solution. My ideal technique, used in a large nice-sounding room or hall, would be a coincident or near-coincident pair of mics (typically cardioid or hypercardioid depending on the required image width of the instrument) placed about four metres back from the front of the piano and about two to three metres up, positioned to be just below an imaginary line extending along the axis of the fully open lid. Moving the mics towards the tail of the piano tends to decrease brilliance and increase warmth, whilst com- ing round more towards the keyboard does the opposite. Often a move of only a few centimetres can make a large difference but there is usually a well deﬁned position somewhere on that arc which sounds just right and a little experimentation will quick- ly locate it. Use microphones with the smoothest off-axis response and extended bass end if possible — typically large- diaphragm capacitor mics like the Neumann KM86 or AKG C414. Many of the lower-cost electret mics are equally suitable, but avoid mics with presence peaks. “In pop music, the piano is typically recorded from a much closer To save setup time, I would normally rig several pairs of mics and drier perspective, giving a perception of greater clarity and in likely positions so that I can quickly compare them and detail, and helping to reduce spill from other instruments.” home in on the best array. This helps to win over the pianist, who is usually keyed up to record and doesn’t want hours of tedious rehearsing while you ﬁnd a decent mic position! It is a matter of personal taste, but for serious solo piano music I would set the microphones such that the piano occupies the central area of the stereo image, say from half left to half right, with the hall acoustic ﬁlling the rest of the sound stage. In an orches- tral setting, the piano image would be smaller still, allowing it to nestle within, but forward of, the wider orchestra’s image. A near- full width image might be more appropriate in pop music, particularly if the piano is not a solo instrument in the ﬁnal recording. If you have a vocalist with the piano, make sure the vocalist mic is positioned to minimise pickup of the piano as the spill will pro- duce unwanted coloration and reduce your control. In pop music, the piano is typically recorded from a much closer and drier perspective, giving a perception of greater clarity and detail, and helping to reduce spill from other instruments. Moving the mics in much closer puts far greater demands on them as much of the sound is likely to arrive off-axis. Ideally, use omnidirectional mics, but if you need directional mics to reduce spill from other instruments it is essential that they have the most smooth and progressive off-axis response possible — sharp dips or peaks in sensitivity at speciﬁc frequencies will become very audible as a coloration which can not be removed with desk EQ. It is also important that you don’t position the mics too close, because the size of the soundboard and spread of the strings means you will over-emphasise a small part of the instrument’s compass. Try to stay at least a quarter of a metre (nine inches) away if at all possible. In a professional studio it should be possible to position the piano so that it ﬁres into a trap, or to position it within a separate booth, both of which will help reduce spill considerably. There are lots of ‘perfect’ close mic techniques for the piano,  A although they are all compromised to some degree. It is worth experimenting with a variety of techniques to ﬁnd the best for the A Close mics over sound holes particular situation. A single mic looking into the piano from B Coincident pair about halfway around the curve, half a metre back and about C C Spaced pair over strings 25cm above the lip can produce pleasant results for a mono con- tribution — experiment with its position along the curve for the best balance. A very common stereo technique is a pair of spaced mics, one directly above the treble strings (typically an octave above middle C) and the other above the bass strings, both about a quarter metre above the strings. The top mic needs to be about a quarter of a metre away from the hammers and the bass mic A positioned in the foot of the instrument where the smoothest bass response can be obtained. This technique works best with the lid removed or fully open to get the maximum effect from the soundboard, and it can be impossible to get sufﬁcient height for the microphone at the bass end with the lid only partially open. C The two mics can be panned partially left and right as required, but beware phase cancellations in mono. A way around this is to use a coincident pair of cardioids around the middle of the piano, B but at a greater mutual angle than normal — say 110 degrees — to minimise the tendency to over-emphasise the strings directly below the mic. Again, mics with a very smooth off-axis response
are essential: the more accurate and consistent the polar A Little History pattern, the better the results. The practical invention around 1709 of the ‘gravicembalo com piano e forte’ In general, placing mics closer to the hammers produces a is attributed to an Italian, Bartolommeo, who effectively combined the two more percussive and dynamic sound, but one lacking in most popular keyboard instruments of the time, the clavichord and harpsi- sonority, sustain and warmth. It can be very effective in chord. He took the action from the clavichord, replacing its metal blades the right context, but beware transient distortion in the (which struck the string) with leather-covered wooden hammers, and incor- mics, mixing console, and recorders (particularly analogue porated the string-damping techniques of the harpsichord. His invention brought viable solutions for the three main problems with this kind of recorders — digital machines tend to have very accurate action: an effective mechanism to project the hammer to the string, an peak-reading meters); consider using microphone pre- ‘escapement’ allowing the hammer to fall back without rebound regardless attenuators, and leave more headroom than you would of whether the key has been released, and the controlled damping of the normally. Moving the mics towards the tail of the instru- resulting sound. ment generally reduces the dynamics and creates a richer, The new instrument was proclaimed at the time as being capable of “pro- smoother sound, free of the clatter of the hammers. ducing a sound more or less powerful according to the force with which one depresses the key”. However, although these early instruments contain all If isolation is a real problem, pressure-zone mics can be the elements of a modern piano, they were not an immediate success and taped to the inside of the lid in roughly the same posi- much of the pioneering work was forgotten. An organist, Gottlieb Schroter, tions as previously described with the lid open, half open, is often credited as the German inventor of the piano as he reinvented a suit- or even shut entirely (dress the cables carefully, though, so able hammer mechanism in 1717, but it was not until the 1740s that the idea that the weight of the lid does not damage them). Apart was widely accepted. Another German, Gottlieb Silbermann, came up with from the inevitable CLANG as the tape supporting one the ‘Prell Mechanism’ to solve the problem of rapid repetition of notes, and of the mics gives up half way through the best take, this Andreas Stein added an escapement to this in the 1770s to produce the cel- ebrated ‘German or Viennese Action’, which was when composers started can be a very effective technique, although some heavy taking the instrument seriously. Instruments of this period are generally EQ is often needed to remove the boxiness when the lid known as Fortepianos and tend to have a rather dull and overdamped is shut completely. The other solution to the problem is sound in comparison with modern instruments. Many of these pianos provided by contact mics like the C-Ducer range. These retained the overall shape of the harpsichord and resembled a rectangular may be afﬁxed to the underside of the piano, or on to the table (hence the term ‘square pianos’) with the keyboard along the long side soundboard from above and give a very clean sound, and of the instrument, and the strings running perpendicular to the keys, with a although it is rather strange compared to the natural single string in the bass and double strings in the treble. acoustic output of the instrument, it is extremely free of Not all the development of the piano occurred in continental Europe, spill! though; in 1783, John Broadwood took out a patent for an ‘English Grand Action’ which gained considerable fame for its “rich and powerful sonority”. Many engineers favour miking a piano in a rhythm-sec- Frenchman Sebastian Erard produced his ﬁrst piano in 1777 and built a con- tion context near its sound holes in the frame on the siderable reputation under royal protection, but he left France in 1792 due curved edge of the instrument, as this gives a good to the Revolution there, and continued developing the instrument in punchy sound and, with the lid closed, great isolation too. London. His major claim to fame is the invention of the ‘double escapement’ For a single-mic technique try a central sound hole, but I in 1818, a mechanism perfected and patented by his nephew, Pierre Erard in  1821. This new action held the hammer close to the string so that notes prefer two mics, one in the second hole from the top and could be repeated quickly without having to wait for the hammer to fall the other in the ﬁrst or second hole from the bottom. back to its normal resting position, and most of the major piano makers Position the mics so that they look directly into the hole adopted the action under license — Steinway in America, Bechstein and and make sure that they are below the line of the closed Steinweg in Germany, and Broadwood in Britain, for example. lid. Use heavy low-table stands with felt or sponge on Around this time the piano had a compass of six octaves, piano and sustain their base, and take care dressing the mic cables so that pedals, and had acquired an iron frame which made it more powerful and the weight of the lid does not damage them and they do allowed triple strings in the treble and single-wound steel strings in the bass. not vibrate or rattle. Small omni mics work well in this The iron frame of a full-size modern grand piano has to sustain some 20 tons application, and it is often worth using the pre-attenua- of string tension! In 1828 the idea of an upright piano was conceived, with tors. This isolation can be further improved if necessary the strings arranged vertically and crossing diagonally to reduce the overall height, bass from top left to bottom right and treble in the opposite direc- with heavy drapes over the piano (all the way to the ﬂoor tion. It was in this domestically acceptable form that the piano conquered preferably), although extensive EQ will be required to the drawing rooms of Europe through the end of the 19th and much of the make the piano sound more natural and less closed-in — 20th century. The instrument continued to develop in minor ways, Steinway particularly in the 2 to 6kHz region. Mics with presence introducing in 1880 a third pedal on their largest instruments to sustain the peaks can be used to advantage in this context. lowest three octaves independently of the rest of the keyboard, for example. For the ultimate in isolation, do as Tori Amos does in her The modern eight-octave instrument employs felt-covered hammers to concert tours. Use a piano equipped with MIDI to drive a strike the strings and a damper mechanism which only damps the string when the key is fully released. A sustain pedal holds the dampers away from decent sound module — the result is total isolation, the strings regardless of the position of the keys, and the soft pedal either which is perfectly suitable for live sound when the full reduces the throw or travel of the hammers so that they strike with less band is playing. For the quieter numbers, revert to the force, or shifts their position so that they strike fewer of the available strings mics over the piano. for each note. Published in SOS May 1999
IVORY POWER Acoustic Piano Miking Workshop PAUL WHITE With so many excellent and inexpensive MIDI piano modules currently on the market, you might wonder why anyone bothers to go to the trouble of recording the real thing — or at least, you might if you haven’t already listened to the difference between a good piano and its sample-based emulation. Now, I didn’t get where I am today without knowing the difference between a good piano and its sample-based emulation; the truth of the matter is that a piano is a living, breathing instrument full of reso- nances and vibrations that are far too complex to emulate with absolute accuracy. For example, whenever you play a note on a real piano, the other strings also vibrate in sympathy, but in different ways depending on which note you’ve played and how hard. If you play two notes at a time, the pattern of sympathetic resonances gets more complex, but because of the way in which most electronic pianos are sampled, the best you can hope for is that each note will be accompanied by the sympathetic resonances that occur when that note is played in isolation. And unless each separate note is sampled (as opposed to one note being trans- posed to cover several keys), the resonances will also be transposed depending on the note you play. Then there’s the way in which the timbre changes with dynamics to consider. Velocity crossfading between a few discrete sam- ples or using a velocity-controlled ﬁlter is never going to capture the subtle nuances of a real piano played by a virtuoso per- former, and while a MIDI piano might be ﬁne as part of a mix, few piano players feel entirely comfortable using them for solo per- formances or prominent parts. In such cases, there’s no alternative but to get out the mics and record the real thing. The Piano Sound When it comes to recording, the acoustic piano isn’t without its problems; for a start, the sound doesn’t just emanate from one convenient point but from the strings, the soundboard and the casework of the instrument, and it’s only when all these vibrat- ing parts make their contribution that a true sound can be captured. To further frustrate the recording engineer, there are vari- ous mechanical noises, such as the pedals and dampers, that must be minimised. A change in playing style is sometimes all that’s needed, but it’s not uncommon to have to wrap the pedals in cloth to stop them thumping. And, of course, you have acoustic spill and room acoustics to worry about. The Grand Gesture Most important piano recordings are made using a grand piano unless the musical style speciﬁcally needs the sound of an upright, and it’s generally thought that the larger the piano, the better the sound, especially at the bass end. Before getting into mic positions, it’s necessary to think about the sound of the instrument and the type of mics that will be need- ed to do it justice. The piano spans the entire musical spectrum, from deep bass to almost ultrasonic harmonics, so a microphone with a wide frequency response is a must. A good capacitor or back-electret microphone is the preferred choice, though you can  exercise a degree of artistic choice in deciding to go for a ruthlessly honest small capsule model, or a more ﬂattering but less accu- rate large-diaphragm mic. Aside from their excellent frequency response, capacitor mics are very sensitive, which means they’ll be able to capture the dynamic range of the instrument without introducing unwanted noise, even when you’re recording from sev- eral feet away. For demo work, good dynamic mics will produce acceptable results, but capacitor models are really the only choice for release-quality recordings. Pianos are most often recorded in stereo and any of the standard stereo mic techniques may be applied. You can use spaced omnis, coincident cardioids, MS pairs or PZM mics, though if you’re worried about mono compatibility, you may feel safer stick- ing to a coincident mic setup rather than a spaced arrangement, as spaced mics, by their very geometry, introduce phase effects which may cause the sound to change for the worse when you hit the console’s mono button. On the other hand, spaced micro- phones do allow more control in balancing the upper and lower registers of the instrument if you opt for a close-miking approach. Some engineers habitually use three or more mics, but this runs the risk of more serious phase problems, so unless you’ve got plenty of time to experiment, it may be safer to stick to a stereo pair. The only exception to this rule is when using spaced omnis at a distance from the piano, as this often leads to a lack of deﬁnition in the centre of the soundstage — an additional centre mic can help to hold the sound together. Mic Positions Before deciding on a mic position, decide on the sound you want. Pop recordings may require a bright, up-front sound, where accuracy is less important than getting the right type of sound, while for classical and jazz work, you will probably want to cap- ture the instrument as accurately as possible, including a little ambience from the environment. Assuming that the room is sympathetic to the piano and that spill from nearby instruments isn’t a problem, a simple stereo pair
positioned between six and ten feet from the right hand (opening) side of the piano may be all that is needed. If the sound is becoming clouded by room ambience, you can move in closer, whereas if the room is making a positive contribution to the sound, you can afford to move the mics further out. Choosing cardioid mics means that you can work further from the piano than with omnis for the same amount of spill or room ambience, so if the room really isn’t helping the sound, using cardioids or even hypercardioids might help. Keep the mics at a height such that they’re aimed about halfway up the inside of the open lid. If the room acoustics dictate that the mics have to be brought in very close, it may be advantageous to add a little artiﬁcial reverb afterwards, though this should be used sparingly because the sympathetic resonances of the piano’s own strings and sound board provide a type of reverb. For pop work, close miking is often employed to create a more cutting, ‘in-your-face’ sound and one popular technique is to position the microphones inside the open piano lid between six and ten inches from the strings, close to the position where the hammers strike the strings. Though cardioids may be used, omnis might be a better choice as they have a more accurate off-axis response which tends to produce a more even tone across the strings. One covers the higher octaves and the other the bass end, and though this doesn’t produce an accurate stereo recording, it does sound good in stereo. Having said that, it may not be wise to pan the two mics to the extremes, as you could end up with a piano that sounds about 20 feet wide! Trust your ears on this one and use just enough panning to create a convincing end result. Close miking has the additional beneﬁt of reducing spill from other instruments, and if even greater separation is necessary, blan- kets may be draped over the piano lid so as to cover the opening. With any method involving spaced mics, whether close or distant, it’s as well to do a mono compatibility check by running through scales using the whole keyboard. Any unduly loud or quiet notes, or groups of notes, that may be attributable to phase addition or cancellation should be quite evident, and if the mono compatibility has suffered too much, try changing the spacing between the mics slightly and ensure that there is at least three times (and ideally ﬁve times) the distance between the two mics as there is between the mics and the strings. I’ve suggested a few mic positions based on experience and common practice, but don’t be afraid to experiment, because near- ly all initial mic setups can be improved upon or ﬁne-tuned simply by trying new positions. For example, if you need a more mel- low tone or a fuller sound, think about putting a mic under the piano to capture more of the sound from the soundboard. Similarly, if the room is too live or coloured, improvise screens around the piano using bedding or sleeping bags. Upright Pianos Organic Reverb Though this description is likely to offend the purists, the upright piano can be thought of as approximating There’s one little trick that’s so old I’d forgotten it until Gateway’s Dave Ward a grand piano turned up on end — when it comes to brought it up at the recent seminar we held at the APRS show. As a novel alternative to reverb, use an effects send to drive a small instrument ampliﬁ- miking it up. The sound board is now at the back rather er or hi-ﬁ amp and speaker placed underneath a grand piano or behind an than underneath, and because there’s no single, large lid  upright piano. Close-mic the piano strings, jam down the sustain pedal using covering all the strings, the only way you can close-mic a convenient brick, and use the sympathetic resonance of the strings as a it is to remove some or all of the front panelling. reverb substitute. This works particularly well on plucked or percussive sounds, and with the current emphasis on ambient/chill-out music, it could The upright piano has a noticeably different tone to prove useful. Note: miking up your sampler loaded with a Steinway grand the grand, especially in the bass register, where it pro- piano sample set doesn’t achieve quite the same thing. Perhaps the ﬁnal duces a less rich sound, but you can still get a good proof that the real thing is still the best? miked-up sound with a little perseverance. A stereo PZM Mics pair, either coincident or spaced, can be positioned on boom stands above the instrument, with its top open. Some engineers like to use PZM or boundary mics for recording piano — Check for an even tonal balance right across the range the underside of the piano lid makes a perfect bafﬂe for this. Simply tape the two mics to the underside of the lid with one mic favouring the high strings of the instrument and move the mics if there are any and the other the low strings. Warning: use adhesive tape that can be obvious dead or hot spots. Spaced mics are easier to removed without damaging the ﬁnish, especially if you’re dealing with a con- use as they can be moved independently to balance cert grand! Though the popular Tandy PZM mics don’t turn in anything like the high and low end of the instrument, but the down the performance of professional studio PZM or boundary mics, they can side is, as ever, the potential for audible phase prob- yield unexpectedly good results when used in this way. lems. Standing the piano close to a solid wall can help to beef up the bass end by getting the boundary effect on your side, and if the room suits the piano sound you’re after, you can move the mics back to a few feet behind the player. A room with a tiled, wood- en or stone ﬂoor will help maintain a bright, lively tone, whereas carpet will tend to rob the sound of some of its sparkle. If you’re struggling to get a mic position that works, it’s always worth remembering that an instrument nearly always sounds OK to the person playing it, so try setting up the mics to ‘look’ over his or her shoulders. When close-miking the upright piano so that the mics are pointing directly at the strings, you can choose to mic either the sec-
tion beneath the keyboard or the section above it, the main concern being to get an even level across the keyboard and to check for mono compatibility. Because upright pianos are often set up in imperfect rooms, and because a great many of them are indifferent instruments, a lit- tle equalisation may be useful in shaping the sound to your needs. However, keep EQ to a minimum; use gentle slopes or cuts rather than harsh boosts, and to add sparkle, use a little boost at around 6kHz, or apply an exciter (sparingly). An indifferent upright played in a carpeted room may beneﬁt from both high-end EQ and a little artiﬁcial ambience or reverb, plate settings being the most ﬂattering. I hope that this article has shown that there’s no real black art to recording the piano — you just need to apply a little logic and be prepared to experiment. If you’re on a tight budget, a couple of cheap PZMs from your local Tandy shop will work far better than they could reasonably be expected to, given their price, and with the preponderance of cheaper capacitor mics, even doing the job seriously isn’t prohibitively expensive. Don’t be afraid to give it a try — providing your mics are half-decent and the piano is in tune, you’re almost certain to end up with a usable recording. Published in SOS October 1994 