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Get The Most Out Of Your Upright Piano

Upright: Done Right! By Neil Rogers
Published December 2019

The author's Knauss Coblenz, a century-old underdamped, overstrung piano, in its usual corner of Cambridge's Half‑Ton Studio.The author's Knauss Coblenz, a century-old underdamped, overstrung piano, in its usual corner of Cambridge's Half‑Ton Studio.

With a little TLC and the right miking technique, even the most neglected piano can produce great recordings.

Whether a grand or an upright, a real acoustic piano is a beautiful instrument. Yes, there are dozens of great-sounding sample libraries, but I always enjoy the challenge of recording the real thing and tailoring the recording to the track I'm working on; it's a very different, and arguably more satisfying, experience for both player and engineer. So, despite having only a moderately sized live room here at Half‑Ton Studio, I choose to keep and maintain an upright piano. I love the character it can bring to a recording session, and the availability of the real deal is also seen as a big plus by many clients. However, owning a real piano and keeping it maintained to a decent, recordable standard is quite a commitment. For starters, pianos require regular tuning — which really isn't a DIY job — and they occupy a good chunk of space too.

In the first part of this article I'll explore how an upright piano can be set up and maintained to a recordable standard, and in the second I'll compare several miking techniques. To help me in this, I invited Steinway-trained piano technician Marcel Kunkel along to service my piano, to talk me through his approach, and to offer readers a few pointers on what to look and listen out for if they're considering buying an old upright. Marcel's also a great pianist and keen recording engineer and, with fellow SOS writer Matt Houghton also joining us on the day to take some photos, we all took the opportunity to compare notes on some recording techniques.

The Piano's Sound

While tuning, Marcel explained that you don't simply tune a  piano to be perfectly in tune in one key — it's an equal-temperament instrument, designed to work in any key, and the relationship between certain notes is crucial.While tuning, Marcel explained that you don't simply tune a piano to be perfectly in tune in one key — it's an equal-temperament instrument, designed to work in any key, and the relationship between certain notes is crucial.A good piano technician can, obviously, tune a piano — but he or she can also change its sound considerably, even tailoring the tone and dynamic response to suit a specific player or recording. So, before he even started to tune it, Marcel asked, "How do you want your piano to sound?" I'm not sure I really understood the question! I'd hitherto considered my piano an instrument with its own sound, with the piano technician's job being to make the most of it. So Marcel demonstrated how much the instrument's tonality and playing feel can be changed. He emphasised the importance of the relationship between player and technician, pointing out what an unusual state of affairs it is for a musician to be unable to tune their own instrument! With a wry smile, he remarked that this situation can come with a lot of baggage, and that the relationship between serious players and their technicians can become very personal.

Of course, I was talking not as a player but an engineer who records other people playing my piano. I explained that I like my piano's slightly darker–than–typical tone; it generally works well for the sort of indie-rock and electronic material I often produce, where I often want the piano to 'sit' in a mix rather than sound bright and up-front. It works less well on sparser arrangements, especially where piano is the only accompaniment to a vocal. With such material I become acutely aware of any clunks and squeaks, and of the inherent lack of fullness in the low end that you get from any upright, compared with a grand. I also mentioned that a few notes either side of middle C seemed to 'stick out', sounding a little louder than the rest. Having patiently listened to my ramblings, Marcel removed both front panels from the piano, opened his toolbox and set to work.

Tuning & Regulating

First, this meant an initial tune. Marcel explained that his basic approach isn't a simple linear process of tuning each string to perfect pitch; he's more often listening to the relationship between many different pairs of notes. This is a highly skilled process that relies on a complicated mathematical system. It is explained more fully in the 'Tuning: Imperfect By Design' box.

By 'needling the felt' individual notes — or indeed a  whole piano — can be made to sound softer.By 'needling the felt' individual notes — or indeed a whole piano — can be made to sound softer.After tuning, Marcel calls the next stage, during which he assesses and fine-tunes the mechanical aspects of the instrument, 'regulating' the piano. He checks whether the action works as it should, and listens carefully for issues with the 'trap work' (the mechanism linked to the pedals) that either cause unwanted noise or affect how the instrument feels to play. He'll listen out for creaks from the player's seat too, since they're just as annoying on a recording. Even really high-quality instruments exhibit mechanical noise, and I actually like there to be a little of this, as it can add character and give the listener subtle signals that the recording is of a real performance. Still, it's important that they're not distracting, and I know from painful experience that some of those appealing little quirks can quickly lose their charm when you're mixing!

To stop the author's instrument squeaking and creaking, Marcel got down on the floor and applied some lubricant — one of the few jobs a non-specialist could probably take care of.To stop the author's instrument squeaking and creaking, Marcel got down on the floor and applied some lubricant — one of the few jobs a non-specialist could probably take care of.I was aware of a few undesirable noises, but Marcel spotted more, including some 'creaks and squeaks' which related to problems with the pedals. To my surprise, there was a screw loose on the trap work for the sustain pedal, and addressing this and applying small doses of silicone-based piano lube tamed the worst offenders.

Next up was 'voicing', which is about finessing the instrument's tone and, in engineer-friendly speak, Marcel drew the analogy of applying a separate EQ to each note. To the casual observer this process can appear somewhat random, but essentially it is one of trying to achieve the same sound on every note across the piano's range, so that each note, when played at the same velocity, is consistent in tone. Marcel explained that a well-voiced piano feels easier to play, and thus encourages a better performance. He also demonstrated how a technician can make the whole piano sound brighter or more mellow. Understanding my preference for a slightly darker tone, he didn't try to change the overall sound too much, but instead focused on making that tone more even.

Marcel drew our attention to two notes that 'poked out' slightly in a way I hadn't previously noticed. They weren't actually louder, but their brightness gave that impression, and to address this, Marcel used a technique called 'needling the felt': using a special needling tool to prick, and thus soften, the felt on the hammers to mellow the tone. While we were on the subject of changing the tone of the notes, I asked Marcel about the famous 'tack piano' technique, which involves putting drawing pins on the hammers. He conceded that it can create an exciting sound, but pointed out that doing this will, unfortunately, wreck the hammers on the instrument — and that they're quite costly to replace!

At one point in the 1900s... there were 200 full-time piano makers in Berlin alone!

Recording

With the piano now nicely tuned, regulated, voiced and cured of unwanted creaks and squeaks, it was almost time to get some microphones out and do a bit of recording. First, though, we wanted to experiment briefly with the placement of our freshly serviced piano in the room. Unlike grands, upright pianos are designed to be positioned against a wall, but I've often found that pulling my piano about a foot out seems to open up the lower end slightly — and, of course, some common miking techniques require access to the rear of the instrument. So we tried moving it away from the wall in its usual corner of the live room, to see if it made much difference to the sound.

Matt and I wondered whether any small knocks and bumps when moving the piano might undo some of Marcel's tuning work, but he said that careful movements on the instrument's wheels should be fine, pointing out that concert pianos are often wheeled about on stage. A piano technician is much more worried about changes in temperature (caused, for example, by stage lights or heating in close proximity) than by the piano being moved with care. As well as trying a few different distances from the wall, we observed the effect of opening the top lid and removing the front.

Rather than throw lots of mics up at this stage — which would mean things got a bit silly every time we moved the piano — we decided to set up one single high-quality stereo array a few metres away from the instrument to give us a decent reference of what the piano actually sounded like in the room. DPA had kindly lent us their wonderful high-quality 3506A stereo recording kit, and for this job, we positioned this spaced stereo pair of ST4006a omnidirectional mics somewhere near the centre of the room, orienting the array to face the front of the piano, with middle C on the keys roughly in the centre of the image.

Here you can see the author behind the glass in the control room, listening to a clean and detailed image of the piano in the room as conveyed by a stereo pair of DPA microphones.Here you can see the author behind the glass in the control room, listening to a clean and detailed image of the piano in the room as conveyed by a stereo pair of DPA microphones.

Both in the room and listening to the sound coming over these mics in the control room, there were clearly audible changes in the tone of the instrument when it was moved away from the wall — even by only one or two feet — and comparing the test recordings confirmed my preference for placing the piano away from the wall. I also thought the sound a little more pleasingly 'rounded' with the top lid closed and the front on (which, after all, is the way the instrument was designed!). As one last test at this stage, we used another technique, which Marcel uses at home with his own piano, which simply involves draping some heavy duvets or blankets over the top and back of the piano. This trick has the effect of 'dulling' the sound quite dramatically, and could be just what's needed for a particular song or recording session.

Lots Of Mics

When preparing to record an upright I'd suggest that it's well worth investing time in getting the sound you want in the room before reaching for the mic locker. Having settled on a placement for the piano around three or four feet away from the wall, which allowed us enough room to position some mics around the back of the instrument, we left the front panel on but the top panel open, to allow us to try some common techniques with mics pointing towards the strings.

The author watches Marcel perform, as he auditions the different mic setups via the preamps in his Audient ASP 8024 console.The author watches Marcel perform, as he auditions the different mic setups via the preamps in his Audient ASP 8024 console.We make no claim to have undertaken an exhaustive comparison of every technique and mic choice — there are so many ways to record an upright piano that this would have been impossible to do in a day. Still, we covered quite a bit of ground. Comparison of techniques is easier if you set things up so that you can capture the same take with all the mics/techniques at once. Happily, we had plenty of identical clean-sounding preamps on my Audient ASP 8024 console, and more than enough mics, so we rigged all of the mics up for the various techniques (described below). Marcel, who is an excellent pianist, then played a few pieces while Matt and I listened in the control room and I captured everything into Pro Tools.

What were we listening out for? Well, we weren't listening for one perfect piano sound. 'Perfect' depends on context; I'd approach recording a piano that's going to sit in the context of a full band recording very differently to how I'd record one for a less busy production. A 'full range' piano recording, for example, takes up a lot of sonic space, with a large proportion of the frequency range and stereo soundstage being occupied by the piano. In many pop, rock or indie settings, on the other hand, the piano might only contribute a few chords spanning an octave or two in total, in which case a beautiful stereo recording covering the instrument's full range might be counter-productive.

I was also interested in seeing what positions might capture fewer of the squeaks and creaks of a more 'characterful' piano, and whether any of the positions might lend this one a slightly 'grander' feel than we could hear in the room, for those occasions where I need it to stand on its own. In short, I was looking for techniques that would give me different options to suit different projects.

As most of the options we tried were stereo configurations (somewhat inevitably, given the physical size of the instrument), I also wanted to know how the sound would translate when heard in mono; it can ruin a mix if the piano drops significantly in level when heard on a single speaker.

Techniques Compared

Here you can see the placement of the various mics at the front of the piano, with the DPA spaced stereo pair further back, just in shot, and then a  pair of AKG C414s and a  Royer stereo ribbon mic closer to the strings, along with a  single AKG D19 'Beatles mic' overhead.Here you can see the placement of the various mics at the front of the piano, with the DPA spaced stereo pair further back, just in shot, and then a pair of AKG C414s and a Royer stereo ribbon mic closer to the strings, along with a single AKG D19 'Beatles mic' overhead.I had in mind four or five different ways I might choose to mic an upright, and Marcel was keen to show us a few techniques that he likes to use in his home studio too. I've described them all below and offered some opinion on the results from each one. As there's a strong element of personal preference involved, I'd encourage you to listen to the sounds for yourself and make your own mind up. To that end, you'll find a number of clips on the SOS website, along with a few additional thoughts on what we felt each option might offer in a session.

Stereo Room Recording: This was the reference pair of DPA microphones described above, and consisted of a spaced pair of omnidirectional small-diaphragm capacitor mics around four or five feet away from the piano. The level of detail captured by these mics is extraordinary, and although you don't get any real sense of 'ambience' in a smaller live room like this one, it definitely conveys a 'being in the room' realism, and there's all the fullness that the lower end of this piano had to offer. I think a lot of this effect would be wasted in a busy production, but for a stand-alone performance, this could work really well (perhaps in combination with a more direct close-mic option).

A closer view of the position of the AKG C414 and Royer ribbon mics.A closer view of the position of the AKG C414 and Royer ribbon mics.Stereo Ribbon Pointing At The Strings: This has been something of a default technique for me on a busy recording session. It employs a stereo ribbon mic (Royer SF-12) about four or five inches from the piano, with the centre of the stereo array pointing at the strings for middle C. You don't get much bottom end from this technique (and it can introduce noise if you have to crank the gain on your preamps, these being passive ribbons), but it can produce a very balanced sound that works well for a variety of material. Relying on a single stereo mic, it's also mercifully quick to set up in a busy session. The sense of stereo 'spread' is very natural sounding, and the recording is relatively mono-friendly.

Pair Of Capacitor Mics Pointing Towards The Strings: This common technique involves positioning a pair of cardioid capacitor mics so that one points towards the bass strings and the other covers the higher, treble keys. We used a pair of AKG C414 B-ULS mics around four feet apart and four or five inches from the strings. As you'd expect, you get a brighter sound than from the ribbons, but it's nicely balanced and is another good all-round option that would work well in many settings. The sense of stereo 'left to right' is impressive, sitting sort of in front of my monitor speakers, but note that there's quite a dramatic drop in volume when listening back in mono. You might want to bear this in mind in a sparse production, though pulling the mics a bit closer together would help reduce the effect.

Mono 'Beatles Mic': This uses one AKG D19 vintage cardioid dynamic mic, positioned two feet above the middle of the piano, pointing down at the strings. This is vaguely similar to how some of the well-known Beatles piano recordings were made at Abbey Road — though without the vari-mu compression or EMI EQ! This technique yields minimal bottom end, but it does produce a familiar-sounding 'jangly' piano, with lots of bright, mid-range presence. It will not be great in many scenarios, but could be just the thing to cut through a busy production.

Perhaps the most unusual technique of the day was one that Marcel uses in his home studio: a  pair of PZM boundary mics taped to the removable front panel of the piano. It yielded a  surprisingly usable sound and was a  low-cost option.Perhaps the most unusual technique of the day was one that Marcel uses in his home studio: a pair of PZM boundary mics taped to the removable front panel of the piano. It yielded a surprisingly usable sound and was a low-cost option.PZM Mics Inside The Piano: This slightly quirky technique is one that Marcel brought to the table. It involves taping a pair of inexpensive Realistic PZM boundary mics to the inside of the bottom panel of the piano. You then put the panel back on so that the mics are inside the instrument, with their cables trailing out. It's a little fiddly to set up, but the result is dramatic, giving an almost scooped sound with enough bottom end that it really begins to sound much more grand. Not surprisingly, however, it also captured a lot more of my piano's noisy trap work, and the creaks were very prominent compared with other techniques.

Spaced Pair Of Cardioid Capacitor Mics To The Rear: We positioned a pair of Neumann U87 large-diaphragm capacitor mics, set to cardioid, around three or four feet apart, just below halfway up and about four inches from the back of the piano. I was really impressed with this option: not only did it capture a very usable, balanced sound with a nice stereo image, but it also captured next to no mechanical or key noise. For those sessions where it's important to have a bit less character, this would be an excellent option. Mono compatibility was no worse than the other spaced stereo options we tried on the day.

Around the back, we tried a  similar spaced cardioid pair setup for two studio stalwart mics: the Neumann U87 large-diaphragm capacitor mic and the Shure SM57 dynamic.Around the back, we tried a similar spaced cardioid pair setup for two studio stalwart mics: the Neumann U87 large-diaphragm capacitor mic and the Shure SM57 dynamic.Spaced Pair Of Dynamic Mics To The Rear: We felt it was important to include some lower-cost mics in our tests, so we positioned a pair of Shure SM57 cardioid dynamic mics just below the U87s, pointing at the back of the piano. This turned out to provide another surprisingly good-sounding option. Although the mid-range 'poke' might be too aggressive for a more stripped-back arrangement, it gave a clear, bright sound that would work exceptionally for a fast, busy piano part that needed to compete with other instruments in a mix.

Conclusions?

So what did our day of experimentation tell us? Well, for starters, my piano really did sound a whole lot better for all the careful work Marcel put in to set it up nicely. Some of the things he did addressed issues I'd been aware of, while others solved problems I'd not previously noticed. The result was a piano that sounded and played much better than before. A good instrument makes more difference than all the mics, preamps and EQ in the world, and I think a good piano technician more than justifies his or her modest fee!

Miking does make a difference, but there is no one perfect setup with such a complex instrument, and all the techniques we tried captured noticeably different recordings. For sessions where the piano needs to stand on its own, the more expensive capacitor and ribbon-mic options seemed to provide more richness, but it really is all about considering what kind of sound you need for a given production. The experience definitely reminded me that I should make more of an effort to pull my piano out and get some mics around the back of it! Not only did we get a balanced and very usable sound from both of the pairs we tried at the rear, but it also neatly side-stepped any issues with unwanted noises.

Of course, two of these techniques could be combined, and I'd encourage you to audition different combinations when you check out the audio files. With upwards of £10,000$12000 worth of mics placed around this piano, I found it really interesting that my favourite setup overall was probably reinforcing the SM57s at the back with just a little of the PZMs inside the front panel to fill out the bottom end. You could obtain both pairs of mics for less than £250$320 in total, and together they'd provide you with bags of flexibility at mix time. In fact, I'm going to invest in another pair of PZMs that I can leave permanently fitted inside my piano for when I need that extra bottom end.

Final Thoughts

Hopefully, this has also helped you assess whether it's worth getting a technician in to look at your piano. For those who don't feel their piano is worth investing in, I have to say that, in terms of impact on a particular song, some of my favourite recordings were done with a piano that I literally found on the street and wheeled down the road to my studio! It was so out of tune that it was hard to work out which note was which but, with a little creative processing using compression, EQ and effects, it really worked.

If you were to take only one thing away from this article, I think it should be that however good the virtual instruments at your disposal, it's well worth making the effort to record a real piano if you have one available. When we all use the same tools and sound sources, it can feel at times that many elements of production are becoming increasingly homogenised, so recording something more individual can be inspiring. My piano may be an unremarkable one, but it sounds like my piano. Whether that matters to the listener is up for debate, but it matters to me, I have plenty of clients who feel the same way, and I think it's added value to many a production. It's worth challenging your assumptions in terms of mic technique and instrument positioning too; it's great to have a reliable method you can turn to when time is of the essence, but with some experimentation you can coax some rewardingly different results from the same instrument.

Many thanks to Marcel Kunkel and The Cambridge Pianoforte Centre for all their help and expertise with this article.

Audio Examples

Check out the accompanying Audio Examples page at www.soundonsound.com/get-most-out-your-upright-piano-audio-examples or click below to download the ZIP hi-res WAV audio files and audition them in your own DAW.

Package icon uprightpianoprep-recording.zip

Tuning: Imperfect By Design

Tuning a piano is complex, since what 'in tune' means isn't what basic theory might suggest. The first thing to note is that the piano is a 'tempered' instrument: it is tuned according to a system that imposes tiny compromises against 'just intonation' so it will sound good when played in any key. (Under the just intonation system, the piano was tuned to sound brilliant in one key only, and needed re-tuning each time a piece was to be played in a different one. Johann Sebastian Bach was so pleased to be introduced to an early version of the equal temperament that he wrote The Well-tempered Clavier!)

A technician starts with one note, usually A (440Hz), and then sets out to build a scale, listening to different intervals and how they 'beat'. Starting around the middle of the piano makes this easier, as the intervals are slow enough to perceive. They might then listen to octaves, which are pure and relatively easy to align, before working their way around the piano.

The technician must also account for inharmonicity — the imperfect relationship, in a world with mass and gravity, between each string's fundamental note and its harmonics. In addressing this, they'll arrive at a result where the octaves are 'stretched out'. In fact, they can, if desired, tailor this stretching according to the preferences of a particular pianist.

A separate challenge is to get the piano to stay in tune. The technician must use a specific technique when moving the tuning pins — otherwise the piano will probably go out of tune within hours! When tuned properly, even after the most demanding performance the instrument should retain its tuning.

Published December 2019