Posted by Brian Lindsay on December 24, 2016
There are only two groups of people who do not shudder with fear when faced with recording the acoustic piano: The well versed and the completely oblivious. Most other recording engineers tend to secretly break a sweat when looking forward to a critical gig recording the piano.
Miking the piano is the big brother of miking the acoustic guitar. The complex tones and harmonics emanate from the whole instrument. For this reason, you will need mics that can handle a large frequency range with minimal off-axis coloration. Keep this in mind when choosing the right mic for the job.
The best recording engineers will arrive at the studio a bit early to look over the piano and be sure that it is ready to record. Artists are never impressed when they arrive at the studio mentally prepared to record a masterpiece, only to sit at the piano while you try to pinpoint an errant squeak or creak.
With a few minutes available before the artist arrives, press on the pedals and listen for squeaks. Remedy these audible blights with WD-40. Wiggle around on the bench and listen for creaking noises. These noises may also be silenced with WD-40 or a screwdriver to tighten up screws. Press on the pedals and make note of how much noise you hear when the damper comes off the strings. This can get pretty noisy, especially when miked up close.
If a studio has a piano as a part of its offerings, don’t make the assumption that it is in tune. Check out the piano ahead of time and call in a professional piano tuner if needed. If the piano is in tune relative to itself but is not precisely tuned to standard pitch (Middle A = 440 Hz), this can be remedied even if a piano tuner is not available.
Use caution when using an electronic tuner to evaluate the tuning of a piano. Often times, artists will request that a professional piano tuner give the piano a certain amount of “stretch”. This means that the lower octave notes will get progressively flat while the higher octaves get progressively sharp. The amount of stretch is tuned into a piano according to the artist’s wishes. Watch for this when checking the tuning of a piano.
While it is always a good idea to think about what kind of a sound you are going for ahead of time, this rule applies all the more to the piano. The way you mike a piano has a drastic effect on the myriad of sounds you will get from it.
As a general rule, miking a piano at closer distances will work better for rock and pop styles that feature a busy mix. With fewer instruments in the mix, distant miking techniques can be employed to capture more of a lush, ambient sound.
Classical styles usually do not call for the percussive effect that you get from close miking the zone where the hammers strike the strings. Inversely, pop and rock recordings may need a percussive sounding piano that adds to the rhythm of the song.
Pay attention here. Although this section will be brief, don’t underestimate the importance of the lid on a piano. The top of a piano is not just there for you to set your beer or wine glass on. It is an important part of the instrument. You can use lid settings to fine tune the tone of the instrument.
Although grand piano lids can be easily set closed, to half stick and full stick, these three settings are not the only ones available. Experiment with lid settings ranging from only a few inches to full stick. You will need to use a book or a custom cut block of wood wrapped in felt to get these smaller lid openings.
Take a moment to think about this resonating air cavity that you are creating and changing when you change the lid settings. A clear understanding of this one point will set your piano recording skills a cut above the rest. As an example, check out the “Paul Cantrell method” listed in the miking techniques below.
While to do suggest that you learn to deal with the way the lid changes and reflects the sound of the piano, I will also suggest that there are times when it is better to remove the lid completely and set it aside.
A concert grand piano was made to be used in a large volume room with nice reverb. A good deal of the rooms that these pianos are recorded in definitely do not fall into that category. For this reason, don’t be afraid to change things up a bit. The pins on most grand pianos will come out easily. Recruit the help of a friend and carefully set the lid aside. When removing the lid of a grand piano, things change in the following ways:
If you skipped the first sections and scrolled down to this one, don’t feel bad. I would be tempted to do the same thing. These techniques are the meat and potatoes of an audio engineer’s repertoire. There are techniques here for one mic and multiple mics and placements that apply to the grand piano as well as the upright. Let’s dive right in.
When faced with miking a grand piano with just one mic, don’t despair. Go to the tail end of the piano and search right above the leg. You will find a sweet spot there. Each piano is different. The lid setting will also affect your exact placement at the tail.
Another yummy location for just one mic is just off the inward curve on the right side of the piano. There are a lot of good sounds in this zone. Experiment by rotating the mic to point more at the hammers or the piano lid.
Some people prefer to capture the sound as the performer might hear it. One way to accomplish this is to place a mic above and just forward of the pianist’s head. This technique works particularly well on an upright piano. Be sure that the mic can “see” the hammers as they strike the strings. If you chose to use a stereo pair here, consider that a coincident XY or a mid-side technique may work the best to avoid phase problems.
Use a pair of cardioid condenser mics to specialize on the high and low end of the piano’s range. The mics are usually placed within 24” of the strings with one mic over the bass strings and the other over the high strings. Always be listening for a “sonic hole” in the midrange and adjust the width and height of the mics accordingly. When miking a piano with no lid, A bit more height will allow the mid tones to blend in better. Adjust the exact angle of the mics for more or less percussiveness from the hammers striking the strings.
If you have been trying to close mic a piano and are hearing phase problems caused by reflections off the lid, you are not alone. Try using boundary mics attached to the underside of the lid itself. This will eliminate the early reflections and also has the benefit of working in a situation where the lid of the piano must be closed.
If you are limited to one boundary mic, try placing it 12” inward from the “hip” of the piano. Multiple boundary mics can be placed to focus on the highs and lows or different parts of the piano in similar fashion to non-boundary mics.
With the help of a stereo miking bar, set up a pair of small diaphragm condensers in an XY pattern. In this example, use cardioid patterned mics. Begin with the mics about 5 feet off the ground and 2 feet from the piano. Feel free to move the pair closer or further from the piano to find the sweet spot that is often located in the “hip” of the piano (The hip is that inward curve on the right side of a grand). The stereo miking bar is a life saver here. It allows you to set the XY pair perfectly and then move the set around without disturbing the stereo alignment. If you try pointing the pair at the distant lid or at the performer, you will find both these orientations have something to offer.
The credit for this worthy technique is due to Paul Cantrell. Place a large diaphragm cardioid mic (like the Sterling Audio ST66) at the “hip” of the piano. It should be peering inside the lid, which will be open only a few inches. Next, place a small diaphragm cardioid condenser mic (such as the Applied Microphone Technology M40) on the back of the music desk pointed over the top of the bass strings and to the far end of the piano. The M40 will pick up the bass sounds while the ST66 will contribute a brighter element to the sound. Note that the slightly opened lid is a critical part of this technique.
Do you see those neat looking holes in the brass plate inside the piano? Stick your ear near them and you will find that they focus some interesting tones. Take advantage of this by placing a small square of foam next to the hole of your choosing and then tape a small diaphragm condenser mic on the foam. The head of the mic should be hanging out over the opening of the hole. When you use this technique blended with additional mics, I suggest that you filter the low end out of the sound hole mic. As you can see, this mic technique works well in situations where the piano lid must be closed.
We all picture ourselves in the studio skillfully placing mics around a shiny black grand piano that costs as much as a car. As non-sexy as it may seem, our reality sometimes involves miking up a small upright piano. Using an A B set of mics on the back of a piano can yield surprisingly good results.
This is the technique that usually comes to mind when we think of miking an upright piano. Open the lid all the way and position one mic over the bass region and the other mic over the treble region. Just like with the same technique on a grand piano, watch out for a sonic “hole” in the mid frequencies. You are likely to get a lot of percussiveness from the hammers in this position.
Most of the panels on an upright piano can be easily removed without the use of a hacksaw. Just be sure to politely ask the owner’s permission before beginning your de-construction project. With panels removed, more stand-off distance is available for your mics.
With the lower panel removed from an upright piano, place a couple of mics to cover the full sound of the exposed strings and soundboard. You will need to watch out for pedal squeaks and bench noises with this technique. The benefits of this mic placement include reduced hammer noise as well as the clicking noise of a pianist’s fingernails on the keys.
As a general rule of thumb, condenser mics work the best for recording a piano. Since the piano is a large instrument that projects sound from a large area, mics need to have very low off-axis coloration. As odd as it may sound, a piano can be a very loud instrument, reaching SPLs of 131 dB or more. Keep this in mind when selecting mics for the job. Let’s look at a few mics that are often chosen for miking a piano.
You will find these small diaphragm condensers being used in XY pairs as well as A B pairs spread about a piano. Use these on the sound holes that appear in the brass plate inside the piano. They also perform quite well over top of an upright piano.
As an alternative to the 4041, the NT5 is also a small diaphragm condenser mic with a cardioid pickup pattern. It can handle 141 dB SPL, not as good as the 4041’s 145 dB but still respectable.
Although this boundary mic is primarily billed as a kick drum mic, it has found its way under the lids of pianos everywhere. The piano is an instrument that includes deep bass. This mic handles that bass with ease.
Use caution when selecting a boundary mic for use on a piano. As some boundary mics were created primarily for use in conference rooms, their frequency response is tailored to that goal. The bass response often drops off around 150 Hz to reduce unwanted rumbles and bumps that are traveling through a conference room table. Because of the extended range of the piano, a mic with an extended range is needed as well. The E901 has this needed range of 20Hz to 20kHz.
In the miking examples listed above, you will find C414s being used frequently. Although these mics are somewhat pricey, they are a very versatile studio mic. The C414 has 9 selectable pickup patterns and can handle SPLs up to 158 dB. It’s broad range of 20Hz to 20kHz make it suitable for the piano as well as a whole host of other instruments.
Sporting an even cardioid polar pattern and the warmth of a real tube mic, the AT4060 is a good choice for piano recording that is moderately priced, considering that it is a tube mic. It can handle an SPL of 149 dB, so the pianist can pound away ‘till his heart’s content. I’m sure that you will find yourself putting this mic in front of a lot more than just the piano.
This piano mic system is nothing short of amazing. It is compact, easy to set up, is unobtrusive looking and the audio performance spec’s are futuristic. The frequency response of this system is 9Hz to 40kHz. What mics have a frequency response like that? Apparently, only Earthworks does.
The pair of omni mics is easy to position on the piano due to the mounting bar and will allow you to close the lid all the way if needed. SPL handling is a worthy 148 dB, so there is no need to worry about overloading a mic. I have always been impressed with the folks at Earthworks. This piano mic system falls right in step with their ability to be way ahead of the curve.
While I have only started you with six mics for recording the piano, there are scores of choices that would do quite well. If you have nice sounding room acoustics in your studio, consider using some omnidirectional mics to pick up a nice blend of the piano and the room it is in. Ribbon mics are often selected for their warm sound. The sky's the limit.
If there is one instrument that I like to capture and mix as natural as possible, it would be the piano. Consider limiting your piano track processing to problem areas, fitting it to the soundscape of a particular song or adding a bit of sparkle.
Unless you are zeroing in on annoying frequencies, you will find that the piano tracks you wind up EQing the most will be in busy songs where the piano has to share space with plenty of other instruments. Here are some general rules for where to look for the different elements of a piano’s sound:
Be sure to use a high pass filter somewhere around 40 or 50Hz to shave off the deepest rumblings of the piano. The piano does a particularly good job of emanating all kinds of deep, non-musical sounds in this ultra bass zone. If you happen to be using any compression, this problem will only be compounded.
In every single article in this recording series, I have painfully stressed the need for subtlety when it comes to compression. This rule doubly applies to the piano. If you over-compress a piano, everyone will know. You might even find your picture in some Wikipedia entry entitled “obsessive compressive disorder”. It could happen.
You should only compress a piano for a couple of reasons: To control dynamic disturbances or to alter the attack of the hammer on the strings. Hopefully, you considered the amount of attack you wanted when you were fine tuning your mic placement, but no one is perfect. Here are a few points to keep in mind when setting up your compressor:
Before dialing in walls of reverb, keep in mind that the piano produces its own sympathetic resonance (on the strings that are not in use) that has reverb effect. I am not telling you to skip the reverb completely, but be aware.
A solo piano recording can support a lot of reverb, while a piano placed in a busy mix may sound its best when mixed nearly dry. If you were not able to capture some room ambience when recording, throw in a little bit of medium room reverb mixed so subtly that you can only tell it was there when you bypass it. This is the fine art of finesse. Go back and re-read the last two sentences. Although it may break your heart to use your reverb plugin so quietly that it is hardly heard, this subtle employment of ambient reverb is a powerful tool.
To place the piano in a large, dreamy space, I strongly suggest you check out a quality convolution reverb. A good convolution reverb is hard to beat. Samples (called impulse files) are taken of real rooms that have desirable reverb. These impulse files are then “convoluted” with your piano track to produce a realistic sounding reverb that is hard to beat out of a box.
Throw these groovy moves into your bag of tricks and they will help you tackle piano recording sessions with the ease of greased lightning:
I know you are going to hate to hear me say this, but recording the piano is all about getting it right at the source. Compression, reverbs and EQ are a lot like the frosting on a birthday cake. If the cake itself tastes like barnyard dirt, no amount of frosting is going to help the situation. Form your piano recording method around this premise and you’ll go far.
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