Posts tagged strings
A few months ago we examined the mechanical and musical basics of the damper pedal. This month we’re going to look at how the una corda, also known as the soft pedal, works.
I was speaking with an older gentleman recently who used to be a typesetter for a newspaper, meaning that he would manually place letters in rows each day for the daily newspaper (pre-computer and pre-typewriter). Each of the letters in the alphabet was grouped together and were called “sorts”.
As the day progressed, depending on what the typesetting would require, you might run out of a certain letter, like a letter E or letter A, for example. And so if you were “out of sorts”, meaning that you had run out of that particular letter, you would go into the storage room of letters and get more sorts, another container of that character. The insinuation is that if you’re “out of sorts”, all production stops until you remove yourself from your work, restock and regroup and then continue on. I love these kinds of stories that reveal the story behind the phrase.
The soft pedal on the piano also has not-so-quaint a story but interesting nonetheless. Cristofori, credited with the invention of the earliest pianos in the 1700’s also installed the “una corda” pedal into his pianos. Being Italian, the phrase “una corda” can be translated “one string”. How does “one string” translate into a pedal we also know as the soft pedal? We’ll look at that in just a moment but first, let’s take a look at the structure of the left pedal on the piano called the soft pedal or una corda.
First of all, grand pianos and upright pianos have very different functioning soft pedals. The grand piano shifts all of the keys from left to right slightly. As you can see in the top picture, the keys move away from the rim at the left. This, in turn makes the hammers off center from the strings they are striking. What’s happening below the surface is that the soft pedal (the left pedal on any piano) is connected to a rod which eventually joins to a lever that swivels. This swivel piece sits under the entire keyboard frame and moves all of the keys from left to right. Why shift all of the keys? On the majority of the keys on the piano there are 3 strings. When you shift the keys using the soft pedal, the piano hammers strike only 2 strings (pictured in the second frame) instead of 3 and thus, the piano becomes softer. But what is also simultaneously happening is that the hammers, being shifted out of their usual strike pattern, are also hitting on fresh felt. When the hammers are aligned to strike at the normal position, they will, over time, have small grooves in the felt. When the soft pedal is engaged, shifting from left to right, the hammer is no longer striking those same grooves. The effect then is that the tone is usually quieter but also softer and warmer in timbre.
Mechanically, upright pianos operate very differently and the soft pedal on any upright is not really any kind of “una corda” since it does not shift the keys. Rather, it pushes the hammers on a single rail forward towards the strings (pictured below). How do closer hammers make the piano softer? It simply gives you a bit more control bridging the smaller gap between the hammers and strings. Hammers on an upright piano travel the full distance to the strings under normal conditions. When they are moved closer, the idea is that with less distance to travel, it will be easier to control. Try this as an example: if you wanted to clap your hands loudly, it is our natural inclination to first separate our hands a fair distance to make the impact greater.
What happens if you move your hands only a foot apart and aren’t allowed to move back before you clap? The result is that the lower distance only allows for lower impact and thus lower volume. Upright pianos work the same way. When the pedal is depressed, a rod simply engages a rail that moves all of the hammers closer to the strings in hopes of limiting the loud playing and making a closer strike distance. The result is quite often negligible and the tone, unaffected compared to a grand piano moving the hammers onto fresh felt.
So where does the term “una corda” come from? Back in the day of Cristofori (early 1700’s), each note on this primitive piano had only 2 strings. Using the “una corda” shifted the keys so that they would only strike 1 string. How different the piano would sound if you would only strike one string at a time. It would sound not only quieter but also thinner. Our ears are so accustomed to hearing 3 strings simultaneously, it would actually be odd to hear a single string resonate at a time. It would be more akin to a guitar. Over the years, however, the term “una corda” has become an anachronism. Although it’s outdated, the term implies quiet and more intimate playing. I guess we could start a quiet revolution and call it Due Corde (2 strings)… but then again, the initials DC are already taken meaning Da Cappo. Piano nerd humour. Hahaa.
As an aside, if you ever get a chance to visit the keyboard museum in Vienna, Austria (Kunsthistorisches Museum Wien), the instruments dating from the 1700’s are completely fascinating and being able to see the historical developments up close is incredible. I highly recommend it!
The teacher has said “It’s time you start looking for a real piano and move up from a keyboard. You’ve outgrown this one”. Really? How does that happen? Just 2 years ago you bought this brand new 88 key weighted digital piano and now you’re being told that it will not suffice. They both have the same amount of keys and it has the same touch as a piano. Why do we need to upgrade? In order to answer that question, we need to look at the differences between acoustic piano (traditional piano with strings and hammers) and digital piano (electronic keyboard that you plug into the wall). The two main areas that substantially divide these two types of pianos are dynamic touch and dynamic tone.
The concept of touch for any keyboard is fairly straightforward: they all have black and white keys. You push one down, it makes sound. But in reality, the constructs of touch are much more complicated. Remember going to the playground when you were a kid? The see-saw was one of my favourites (especially when your brother or sister is on the other end and you decide at last moment to let it crash to the ground seeing them slightly propel off the end in mid air). Anyway, the idea of balance is realized fairly quickly. We all experimented by moving closer and farther from the middle. It took substantial weight to push down the see-saw if you were really close to the center. Piano keys are exactly like that. When it comes to upgrading from digital piano to acoustic, one of the most significant changes is a better balance point. What do I mean by that? When you play the piano, the ideal is to have consistency moving from one note to another. But you also want to achieve consistency from the front of the key to the back. Take a look at the diagram with the two different pressure points marked in red. As the demands for piano proficiency increase, you end up using the entire key surface and not just the fronts. When you look at the cutaway of both digital and acoustic pianos (on the next diagram), you will see that digital pianos have balance points that are too close to the keyboard. It’s like the see-saw principle: the closer you move to the center, the more difficult it is to depress a key. Here’s a test to try: depress a key on a digital piano similar to the red marks on the diagram. Take note to the variance in touch. Digital pianos, by nature of the balance point placement usually have significant touch discrepancy. With acoustic pianos, the balance point distance is substantially further. This creates a more even touch weight from front to back of the key. One sign of a great piano is low variation between the front and back of the keyboard.
Another significant distinction between acoustic and digital is the idea of dynamic touch weight. Have you ever gone camping? Good, because it’ll help with this next analogy. Chopping wood requires rotational inertia. The axe handle pivots in your hand while the weight at the end gathers momentum and chops the wood. Due to the multiplying effect of the rotation of the axe head, the power increases substantially. Any seasoned pianist will be able to tell you that acoustic pianos somehow feel different than any electronic or digital piano. The reason for this is due to this rotational inertia of the piano hammer causing dynamic touch. Take a look at the side cutaway of the upright piano. Labelled is the hammer which rotates towards the string. This rotational inertia, similar to a hammer or an axe – gives a very different sensation than the static weight of a digital piano. A digital piano simply raises or lowers lead weight up and down. It doesn’t have a multiplied force when played louder and subsequently, there is no dynamic force on a digital piano.
There are many other subtle differences that we could consider regarding touch, but the last one we’ll look at is spring assists. Ever so slight and yet perceptible is the idea of resistance in part by springs in the action. In an upright piano, for example, the pivot point of the hammer we just spoke of not only has rotational inertia but it’s also spring loaded. The spring resists the hammer and at low pressure, low volume, you can feel the spring engaged. As the hammer moves closer to the piano strings, the tension of the spring also increases, causing more pressure to return the hammer to reset.
So why upgrade? Longer keys mean better balance from front to back of the piano keys. The rotational inertia gives dynamic touch changing the feel as you play soft to loud. And finally, the spring loaded joints aid the reset. All of these work collectively to define the touch of a piano. When you compare that to a digital piano where the touch weight is simply raising or lowering a lead weight on a see-saw, the difference is significant. In addition to these touch elements, traditional pianos also have adjustable parts to refine the touch components as well.
Final considerations regarding touch: dexterity and injury. After nearly 30 years of teaching, I could tell as soon as I heard a student who had been practicing on a digital piano. How? They have not developed anywhere near the right amount of finger dexterity. You can “hear” that their technique is weak. Dynamic touch brings about correct dexterity. You can especially hear it on quick staccato passages. But the more important consideration is injury. Extended practice time on digital pianos have the propensity towards injury. I’m not a kinesiologist but I think it has something to do with repetitive loud playing on the digital piano. I believe that the force is somehow not absorbed the same way because digital pianos do not have dynamic key weight. When you come crashing down on the keys, if the static weight doesn’t change, the next absorption point is the hands and arms. The dynamic nature of the acoustic piano changes the resistance when you play and for whatever reason, I find it more forgiving.
When it comes to upgrading from a digital piano to an acoustic piano, there are also 2 sound concepts to be mindful of: The first is the continuous flow of sound which we commonly refer to as analog. The second is dynamic timbre referring to how the sound quality changes with dynamics and volume.
First, let’s look at the comparison between acoustic sound and digital sound. The acoustic piano creates sound by a hammer striking a string. The subsequent vibration is amplified by the soundboard into audible tones. How do digital pianos make sound? Digital pianos don’t actually create sound. They simply play back a digital recording of a real piano. But digital sound and live string resonance are different. Digital sound is made up of many frames per second to give the illusion of continuous sound. Natural vibration of a string is a continuous waveform that we perceive differently. I remember the first time I used Skype to speak with my parents a thousand miles away. My aging father found the technology almost baffling. It was great to see their faces and connect but is it the same as being there in person? No of course not. Both methods communicate effectively but the live version brings about a closer heart connection. A picture of a garden or being in the garden, a filmed version of a Shakespearean play or experiencing live theatre, hearing a recorded version of your favourite artist or seeing them live in concert ~ live is simply more than the digital representation. And yes I’m well aware of the fact that there are incredible creative moments that can only be achieved in the digital realm. It’s not that it lacks expression as its own form. My point is that digital piano will always and only be a facsimile of a real piano. And as it relates to acoustic analog continuous sound waves versus a digital recording of a piano transmitted through speakers, natural sound will always be the better choice.
The second concept of sound is the idea of dynamic timbre. Just as acoustic piano touch is dynamic and changes with volume, so too piano tone or timbre changes character with volume. As the hammer strikes the string at soft to loud volume levels, the piano hammer felt is compressed differently. The subsequent tones often go from felty and warm to strident and bright. Depending on volume, other sympathetic tones of the piano also ring. An acoustic piano is not a matter of simply raising or lowering volume but rather, the piano tone changes color with dynamic touch.
Crayola crayons – remember the new boxes you would get at the beginning of the school year? Digital pianos are a little like that small box of 8 colors. In the recordings of digital pianos (called samples) manufacturers have attempted to capture these dynamic timbres. What this means is that when you play from soft to loud on a digital piano, it transitions through the various colors of samples. But when it comes to upgrading, advanced students need to move beyond the 8 Crayola colors. Advanced playing requires shading, nuances and a wider color palette. You simply cannot hand a student a box of crayons and say “Paint me a masterpiece”. It’s physically not possible. You think I’m being facetious but most manufacturers use less than 4 “colors” per note. Conversely, traditional pianos have an infinite number of colors. And that’s just in one note! When you strike more notes simultaneously, the color possibilities and frequencies increase exponentially. Quite often I think back to the famous pianist Glenn Gould. I read that his parents had to lock the piano after 14 hours a day of playing when he was a child. Obviously he was genius and radical in his approach to piano playing but in reading about his life, it’s apparent that he was completely smitten by the tone of the piano. I fear that we don’t give students the capacity to LOVE the piano for its sound. I wonder if we as parents do a disservice to children by giving them the incorrect tools to begin with. There’s this common school of thought “Let’s get a keyboard and if they stick with it, we’ll get them a real piano”. Do children learning the piano ever fall in love with the tone of a keyboard? Have we lost the connection to analog – this continuous vibration of the strings? Does it resonate with us the same way? Have we given them a handful of colours and limit the pure enjoyment of limitless expression?
I believe these are the thoughts and intentions behind teachers wanting more for their students. When they speak to parents about upgrading, it’s not about some high-brow approach to narrow minded Classical performance. It’s the desire to connect with a more fundamental, more organic way of expression in music – one that is beautiful and lovely. So the next time the teacher encourages you to look at a traditional piano, they’re really saying ‘Let’s go deeper, let’s create music, and let’s experiment with touch, with tone and experience music to its fullest extent.”
Over the last few years, I decided to run a few ultra-marathons (marathons run on trails in the forest). And I must go on record by saying that maintaining fitness is much easier than trying to get in shape to begin with. It was an arduous journey trying to get ready for my first event. But when our bodies are used to a certain routine over time, it becomes the new normal. In essence, we train in order to raise the bar for a new level of expectation.
You wouldn’t think it, but pianos can be in shape or out of shape. Pianos can go out of shape mechanically in the way that they play but can also get out of shape in the strings which determines intonation or pitch. Today I’d like to take a brief look at a bit more of a structural and mathematical concept of tuning and pitch. Before we do, we need to examine how and why pianos go out of tune and when you understand why they go out of tune, there is greater understanding with regards to getting them in shape and maintaining tuning stability.
Pictured above are the 3 types of strings on any piano. When you depress a key on the piano, it activates a hammer that strikes the strings. Depending on the zone (high or low), there are different types of strings. The largest bass notes are called mono-chords and only have one string per note. The double stringed notes are called bi-chord where the hammer strikes two notes simultaneously. And then for the top 2/3rds of the piano, a set of 3 strings (tri-chord) are struck simultaneously by one hammer. As seen on the chalkboard, there are 88 keys on the piano. When we separate the notes by type, we see that there are approximately 227 wires (which vary depending on the design of the piano). Multiply this total by the tension from each string (approximately 160lbs per string) and this gives the grand total of 36,320 pounds of string tension pulling on any piano! Note: the string tensions vary from maker to maker, model to model but also within one piano, the string tensions vary considerably. These are simply averages to grasp the concept of how much tension is pulling on the frame. Conservatively, the piano has 18 tons of tension (36,000 pounds) pulling simultaneously and that number can reach almost 30 tons of string tension for larger concert grands.
The wires then pull with an incredible force or tension. The cast iron frame (pictured in gold) together with the structural beams resist this tension. It’s a constant tug-of-war. The strings pull while the cast frame resists. Slight variations in this tension result in change of pitch and an out of tune piano. The question then is: what factors change the pitch of a piano?
There are 3 main elements which affect tuning stability:
1. New strings and windings
2. Tuning pin torque
3. Soundboard environmental changes
1. When it comes to change in tension, strings when installed at the factory will stretch. You wouldn’t think it but new strings have considerable stretch in the steel. The windings, knots and coils will also tighten and stabilize. This only applies to brand new pianos. There is a finite amount of stretch that will happen with new strings and within the first few tunings this will no longer be an issue. There is wisdom in tuning new pianos more frequently until the strings feel like they’ve settled.
2. The tuning pins are the adjustable “pegs” that technicians loosen or tighten with a tuning hammer. They are friction fit into the pinblock ~ usually a multi-laminated plank of wood. Interestingly, in England, they refer to the pinblock as the “wrest-plank”. The word “wrest” (similar to wrestling or wrench) denotes forcibly to pull or in this case, to turn the “wrest pins” (or tuning pins) inserted into the wrest-plank. Because the tuning pins are friction fit into the pinblock, they must have the correct amount of torque (the measurement of how tight fitting the pins are). Too tight and the pins becomes too difficult for a technician to adjust. Too loose and the tension of the string pulls on the pin resulting in loss of pitch. Tuning pin torque then is a significant factor that affects tuning stability.
3. Probably the greatest factor affecting pitch, however is the soundboard. The soundboard affects the tuning stability insofar as the strings cross over the bridge which is connected to the soundboard. In the picture you can see the strings cross over the bridge (adhered to the soundboard). Not only are the strings pulling end to end, but there is something called down-bearing where the strings are pushing down on this bridge. Since the soundboard is comprised of wood, it is subject to environmental conditions. Seasonally as the soundboard absorbs or dispels humidity, the soundboard will arc or flatten slightly resulting in pressure on the strings. Pianos can even go up in pitch if the arc puts considerable pressure on the strings.
All three of these factors contribute to slight deviation in pitch. When the steel strings are new, they stretch and become slack and need to be re-tuned. Tuning pins can move slightly and gradually turn out of position. The soundboard arcs more and then less depending on environmental conditions.
Making Sense of Cents
Pitch is not simply some arbitrary sound but rather, it has evolved into more concrete, measurable and universal terms. A440 is the global standard. A is the note (just above middle C) and 440 is the frequency or speed of that wave measured in Hertz (named after Heinrich Rudolf Hertz accredited for conclusively proving electro-magnetic frequency waves). When it comes to piano tuning, while you can measure Hertz, you can also define pitch in degrees called cents. As seen in the picture, each semi-tone has 100 degrees or cents. A full tone then has 200 cents. What this means is that there are 100 increments or degrees of pitch from one note to the next neighbouring note. So in discussing pitch, being a math and facts guy, I like to know how many cents the piano is out of tune. A piano that is wildly out of tune will be 40 cents flat (pianos usually go flat rather than sharp). So 40 out of 100 cents, if a semi-tone is 100 cents, that piano has fallen in pitch 40% of a semi-tone! Pianos that are tuned regularly might only go out 1-3 cents (out of a total 100). Often, pianos might go out of tune 5-15 cents in a year. What does this depend on? The 3 factors we looked at above. If your piano has gotten over “new string” settling when the piano is first purchased, then that leaves tuning pin torque and soundboard fluctuation as main factors determining pitch or intonation. The pinblock and soundboard will change with humidity. Pianos LOVE stable environments. Baseboard heaters, fireplaces, direct sunlight, drafts… even excessive fish tanks, plants all have bearing on humidity in the room which affects the soundboard which in turn affects the tuning. Change in ambient temperature (and subsequent humidity) within the house but also seasonally will make micro-changes in strings which also create difference in pitch.
Getting Your Piano in Shape
There’s a saying about piano tuning “You can’t tune a piano unless it’s in tune”. Paradoxical? It sounds that way unless you understand the sentiment. The farther out of shape your piano is, the more the tug-of-war will happen. The strings get pulled into shape, the piano tries to pull back to its known comfort zone. If a piano is 40 degrees out of pitch and you raise it to concert A440, guess what ~ your piano will not be at A440. Why? Because the tug-of-war is happening. The soundboard is adjusting to a new level of fitness. The subsequent outcome is that most pianos will pull back ~ sometimes up to 1/3 of the raise in pitch. So let’s take that example of 40 cents. One third of 40 is roughly 13. After tuning to A440 once, the piano will respond by possibly dipping down as much as 13 cents. Most technicians compensate and tune a little sharper knowing that this pull-back is going to happen. And so here’s the part that technicians CAN’T control. They can’t control the adjustment of the piano and the subsequent pull-back in 225 strings. Those strings will pull back at varying rates and thus, one tuning will never do the job getting a piano into shape that is vastly out of tune. The only way to do that is to tune again. You can really only tune a piano when it’s in tune ~ meaning that unless it’s close to pitch, you will never be able to get an exact stable tuning the first time. It is better to keep a piano consistently in tune than to let it drop significantly and try and pull it back into shape.
I’ve heard from many people over the years. “The piano doesn’t need tuning because I don’t play it that often”. While it can be true that a pianist who plays with incredible force can knock a piano out of tune, it is most likely the least contributing factor to making a piano go out of tune. Regardless of whether you touch a note on the piano or not, there is 18 tons of string tension pulling every day, 365 days per year. If a piano is prone to going out of pitch 4 cents per year, it might be out 8 cents in 2 years, 12 cents in 3 years and so forth. And pianos are funny that way. I’ve witnessed pianos that go out 12 cents in one year while others go out 2 cents in 8 years. But in closing, I will state 2 truths:
1. The farther out of shape the piano is, the harder it is to get it back into shape. And it may require more than one corrective tuning
2. Environmental stability is everything
Pianos are introverts. Hah… they like dark shady places where the sun doesn’t shine and no one rocks the environmental boat. The only problem is, we want pianos to be social and live in the center of our lives and enjoy the music with the sunshine. We need to maintain pianos if we want them to sound pure, beautiful and harmonious. I’m a firm believer in the fact that we are the recipients of the music from our pianos. If we train our ears with a consistently out of tune piano, that sound becomes the new normal. With an in tune piano, we communicate proper pitch every time we play. In closing, the message is simple: Regular maintenance is so much better for the piano than letting it drop in pitch for years at a time. Tune at least once per year and you will keep everything from sliding drastically out of alignment. Tune more than that if your ears demand it. And if you haven’t tuned for quite some time, do yourself a favour and get your piano tuned. Nothing is more satisfying than playing a piano that truly sings and really, pianos only sing when they are in tune and each note is in unison. Your piano may have gone down in pitch to such a degree that it might require more than one tune up session but as an old technician friend of mine used to tell me, “The difficult we can do. The impossible may take some time” 😀
For a name of a piano technician in your area, please visit our more than 800 technicians listed with Piano Price Point: HERE
If you live in North America, you’ll surely be aware that Baldwin is a household name. In fact, my first job involving pianos was in the local Baldwin dealership. They have been around since 1862 and were at one point the largest piano manufacturer in North America. At the NAMM trade show this year, I caught up with Tom Dorn (pictured on the right) as I was curious how Baldwin has changed over the last few years knowing that they had been sold to Gibson Guitar Corporation in 2001 and in 2008, moved manufacturing to China. But I was equally curious to know what elements have stayed the same. As I approached the Baldwin booth, I couldn’t believe how the cabinets were identical looking on some of the models from decades ago. Baldwin, in my opinion has always captured the essence of American décor.
Glen Barkman: Tom, they look identical to pianos I used to sell. Are they using similar cabinet designs?
Tom Dorn: These furniture models (B342 & B442) are updated versions of the old Acrosonic pianos and have identical cabinets. The Hamilton studio piano (B243) is the latest version of our institutional vertical, and the model B252 is the updated version of the Concert Vertical (Model 6000). The new Baldwin Professional Series Grands have cabinets that were modeled after the most recent version of Baldwin Artist Grands (M1, R1, L1) that received that cosmetic makeover in the year 2000.
GB: What are some of the features that are unique to Baldwin that are implemented into current designs?
TD: The new BP (Baldwin Professional) Series Grands are done with the same “level” of materials that we traditionally used in Baldwin Artist Grands. The grands feature all-maple inner and outer rims, wet sand cast plates as well as solid Sitka spruce soundboards, Abel hammers, duplex scaling, and real ebony sharp keys. Baldwin verticals have a strong 5 post backframe, wet-sand cast plates, complete with Baldwin full blow action, and are now using Accu-just hitchpins ~ a way to accurately apply downbearing to the bridge from the string hitch. All Baldwin verticals are equipped with a functional middle pedal that is a bass sustain.
GB: What are some new upgrades that the old Baldwins didn’t have?
TD: Baldwin Verticals now have added the felt-strip mute rail or quiet play feature on a small lever on the lower part of the cabinet. This allows us to offer that capability without sacrificing the middle pedal.
The BP178, BP190, and the coming BP211 Grand models all feature the new slow close Magic Lid. This is a hydraulic system that allows you to lift the heavy grand lid with 2 fingers and makes opening and closing the lid on these pianos much easier and safer.
GB: Are there some features like hammers or strings that are the same brand 20 years ago that are still used on today’s pianos?
TD: We still use all maple parts in our actions, and the last change in the vertical action design came in 2002 when we altered the balance rail for faster repetition. We may have different suppliers for some parts, but they are all built to Baldwin specifications.
GB: What prompted the change to build pianos in China?
TD: The global piano market has changed dramatically. The Chinese domestic piano market is approximately 350,000 pianos annually – which accounts for 80% of the world’s new piano market. The USA only sells about 35,000 pianos per year. China simply is where the market is. When I started in the piano business back (way back) in the 1970s, there were many US manufacturers because the US market was selling upwards of 200,000 pianos annually. It made sense to make pianos here because it was the largest market.
GB: What are some of the new models released now? I remember the Artist series grands were M, R, L, SF and SD. That line has been expanded slightly to meet the needs of today’s consumers. What are the sizes of grands now? And uprights? What are the latest models?
TD: There was a 5’2” Artist Grand, the Model M (probably my personal favorite, one of the best small grands ever built). The new grand models are the Baldwin Professional Series (BP) and have a number designation that indicates the size in centimeters. They are BP148 (4’10”), BP152 (5’), BP165 (5’5”), BP178 (5’10”), BP190 (6’3”), and coming soon the BP211 (6’11”). I would suggest that someone who liked the M should try the BP165, the R the BP178, the L the BP190, and the SF10 the BP211.
For verticals we still make 2 Acrosonic 43” consoles (B442, B342). Everything else follows today’s demand for taller uprights. The new BP1 and the B243 are 47”, the BP3 is 48”, and the BP5 is 49”. The B252 is 52” as it is exactly like the model 6000 Concert Vertical.
GB: What makes the new Baldwins sound “warm”?
TD: The ‘warm’ Baldwin tone is a result of using similar materials to the ones that we always have (such as Abel hammers), and by having a product manager at the factory who has worked with Baldwin pianos for many years. Barnabas Fekete inspects each Baldwin Grand as it comes off the line and makes sure it is voiced to sound like a Baldwin.
GB: What’s the advantage of having a mega corporation like Gibson at the helm?
TD: Gibson is obviously no stranger to the music industry. Established in 1902, they have grown to become one of the largest music names globally. Purchasing Baldwin back in 2001 has given Baldwin presence and the stability of a major American corporation. One of the biggest advantages is the Gibson Entertainment Relations Division. Gibson has dozens of offices around the world that are working to promote their brand names. In the case of pianos this can be seen in terms of highly visible placements on TV Shows such as “Glee” or “Arrested Development” and movies such as “Behind the Candelabra” on HBO not long ago. Gibson also maintains the Trumann factory as a parts facility should technicians require parts for older Baldwin USA pianos.
Thanks so much Tom for taking the time to give us some insights into Baldwin then and now. Having been with the company for years, no one would better know than you how this company has transformed into the newly emerged Baldwin Piano Company we’re seeing today. For more information about Baldwin and their products, you can visit their website here: Baldwin Piano
The soundboard of a piano ~ to the naked eye, it looks like a giant sheet of wood located under the strings. To piano makers, this is one of the most critical elements of science in the instrument. Why? The job of the soundboard is to transform tone of the vibrating piano strings into audible waves which also color the tone. Truly, it is inseparable from the voice of the piano.
Doing some light reading 😀 (Wood for Sound by Wegst, 2006, American Journal of Botany) it becomes apparent that soundboards are this careful balance of elasticity and stiffness or rigidity. In the diagram, it reveals that there is a correlation between density of wood and elasticity (Young’s Modulus). Generally the lower the density, the greater the vibrational properties. Balancing this concept is stiffness required to resist what is called the down bearing of the strings – the pressure of piano strings pressing down on the soundboard. So the soundboard makeup is this marriage between rigidity (resistance) to pressure while maintaining elasticity for vibration allowing optimal dynamic range and sound radiation.
What then makes for a good soundboard? We thought it would be appropriate to go to the source. Bolduc, one of the few independent piano soundboard makers in the world allowed us a glimpse at what is involved in the making of a soundboard. Situated in bucolic Quebec, Canada, they supply both to piano makers as well as independent piano rebuilders. So without further, adieu, let’s talk to Christian Bolduc, factory superintendent.
Glen Barkman: Tone wood – why white spruce? Is it structural, is it the density or mass? What makes it ideal for piano soundboards?
Christian Bolduc: The North American White spruce has been used for over a century for the making of piano soundboards, as well as violins and other stringed instruments. It has proven its outstanding tonal properties with the most prestigious North-American piano manufacturers. The cold and vigorous North American climate contributes to the strength of the spruce which offers appropriate structure and elasticity required for making a good and resistant soundboard.
GB: When choosing a great log for tonal purposes, what characteristics are you looking for when you view a log in its natural state? Ie. What diameter, length, areas without branches, bark etc.
CB: We need the nicest spruce logs available for making piano soundboards. Most of the time, we use only the base of the tree and cut just under the first branches. The length of the logs we use can vary from 2.5 meters long up to 5 meters (8-16 ft). The tree needs to have grown slowly, gradually, without any twisting, blue marks or other impurities. After having selected the best logs, only 20 to 25% of the tree will be selected for making a 1st grade grand piano soundboard. The rest of the wood will be used for making upright soundboards because the colour is less important because they face the wall. The remaining wood can also be used for other products such as house mouldings and lumber.
GB:Do you happen to know usually how old the trees are when they are logged and when it is the best time to harvest these trees and why?
CB:The tree needs to be cut in the winter time to prevent any sap that would affect the stability of the wood. We need at least 15” diameter at the small end of the log in order to be able to make the quarter-sawn cut. Most of the time, the trees are at least 100 years old.
GB:Do different types of spruce or other woods exhibit different fundamentals in the piano as well as overtones?
CB:There have been many experiments made by piano manufacturers in the last century using different species of woods for soundboards. The spruce tree is definitely the best material as far as tone is concerned.
GB: What is the rough timeline from logging to soundboard? Logging, drying, cutting, curing, shaping, sanding…
CB: The spruce needs to be cured slowly before moving into production. The most important criteria is that the tree needs to be cut during the winter time when moisture is at its lowest. The logs will first be cut into lumber at our saw-mill and stacked outside for months for a slow drying process. The wood will then be kiln dried a few weeks and stacked again for many additional months. The spruce is at least a year old when we start making the soundboard panels.
GB: What is the ideal “curing” humidity or moisture content in the wood?
CB: The soundboard will need different drying periods during the process of production. In the final step, while gluing it into the piano, the soundboard can reach as low as 4-5% humidity content.
GB: Are soundboards planed and then sanded or rough cut and then thickness sanded?
CB: The spruce lumber is cut into oversized planks. The pieces are color and grain matched and then glued together. The soundboards are sanded to their final thickness in a 74″ wide abrasive wood planer.
GB: Do you customize pianos for specific companies and how do you go about doing that?
CB: We manufacture all types of soundboards based on the piano manufacturers’ specifications. Thickness, shape and grain alignment vary from one piano to the other.
GB: How thick on average is a piano soundboard?
CB: A regular piano soundboard can vary from ¼”(6.5mm) for a small model up to 3/8”(9.5mm) for a concert grand piano.
GB: Why quarter sawn? Why vertical grain?
CB: The main reasons are for stability, strength and sound transmission. The soundboard is firmly glued into the piano but still needs to expand and retract without splitting, depending on the ambient conditions and humidity variations. Maintaining the annual rings in a vertical position guarantees that the wood will change dimensions without cracking. The quarter sawn cut makes it also stronger to support the downward force applied to the soundboard by the strings which can reach over 600lbs.
GB: What is the purpose of ribs to a soundboard? How do you incorporate crown (slight arc) into your soundboards?
CB: The ribs help maintain the crown of the soundboard and also counterbalance for the down force exercised by the strings. The ribs can be pre-shaped to match the crown or glued under tension in a press.
GB: What types of glues hold the planks together?
CB: Most manufacturers from the 19th and 20th centuries have been using the hot-hide glue for gluing soundboard panels, pinblocks, veneers, etc. The hot-hide glue was not only good to fix the parts together but also a very good sound transmitter. Today, we use a glue which was developed with the same philosophy of “sound transmission” as it becomes as hard as glass but with a superior resistance to any type of environment.
GB: Obviously with 19 tons of string tension on a piano bearing down onto a soundboard, the soundboard needs to be stable enough to withstand that pressure. Do you measure clamping pressure when joining planks or have other measurements to determine adhesion and subsequent rigidity and stiffness?
CB: The glue used for laminating the soundboard panels is actually stronger than the wood itself. We may think having maximum force is better, but too much pressure with the clamps is not good. There must still be room left for the glue itself.
GB: Are soundboards finished with resins or lacquers or left in their natural state? Or are they finished by the piano manufacturers who purchase them?
CB: The finishing of the soundboard is done by the manufacturer after its installation into the piano. The soundboard needs to be lacquered in order to seal and protect the wood.’’
GB:How is the soundboard adhered to the inner rim of the piano?
The soundboard is glued to the inner rim as a flat glue joint. There are notches in the inner rim to allow room for the ends of the ribs to fit within.’’
I just want to express my thanks to everyone at Pianos Bolduc for answering questions and also supplying most of the images. Due to the wasteful nature of quarter sawn lumber, it makes me happy to see that Bolduc is also concerned with the environment and not letting any scraps go to waste. They only work with suppliers involved in reforestation. The shorter pieces unusable for pianos are sold to guitar luthiers and the sawdust is used by local farmers for litter while the bark for heating sugar shacks and cottages. Excellent!
For more information about Bolduc, visit their beautifully designed website. There’s lots more information on their company, soundboards and pinblocks as well as an array of tools that they also sell.
One final note ~ if you’re anything like me, you’re curious as to their inscription on their logo “Je veux, Je peux”. Translated from French it literally reads “I want, I can” and the insinuation is that we can really make things happen if the desire is strong enough to succeed. Congrats to Bolduc for nearly 40 years of this pursuit!
Today’s topic is piano dampers. When your finger depresses a key on the piano, the string vibrates allowing us to hear the wonderful tone of the piano. But what happens when we lift that same key? The key returns to its upright position and the tone stops resonating. Why? The piano mechanism called the dampers simply press felt blocks on the vibrating strings to terminate the singing tone.
To understand a bit more about dampers, we brought in Marc Venet from world renowned felt maker Laoureux in France!
But before we delve into piano dampers, we need to take a brief look at the piano strings. On any modern piano there are usually 3 sets of strings: tri-chord, bi-chord and mono-chord. The prefixes of tri- bi- and mono- give away the fact that there are notes on the piano that contain 3, 2 and 1 string. This is significant because as we’ll soon hear, damping 3 strings at a time is very different than damping 1 string. The largest strings on the piano are the bass strings. They are copper-wound strings and produce the lowest notes of the piano where you can actually see the vibration of the string. Conversly, as you move higher in the piano, the frequency of the waveform gets faster and we can’t see the vibration. Piano strings can be called “sinusoidal” from where we get the root “sine” wave. The purpose of the damper then is to stop the wave and subsequently, the sound. The damping techniques and felt types are really different to mute different thicknesses of strings and their varying degrees of energy.
Without further adieu, and knowing a bit more of the background of dampers, let’s talk to Marc Venet from Laoureux.
Glen Barkman: The history of Laoureux, it’s been going a long time and is one of the largest piano felt makers in the world. Can you tell us a brief history of the company and how you got involved?
Marc Venet: Laoureux was founded in 1923 by Mr. Laoureux and after 3 generations of Laoureux’ leading the company until 1976, it wasn’t doing well financially. It was purchased by SCAPA group who bought the company in order to build a conglomerate in European felt business (Naish felts, Royal Georges felt, Laoureux, etc.)
My father was hired at this time in order to restore the profitability of the company Laoureux, which he succeeded to do above their expectations and quite possibly be the reason why Laoureux is now the only felt maker from this group that survived and producing today. The choice he made was to concentrate on high quality, hand made felts and avoid mass market felts like those found in the automotive industry, for example, which have bigger profits, yes but also involve big risks and large turnovers. It was a good choice. My father finally bought the company in 1988 and I joined the company in 1998.
GB: There are 3 types of strings and yet 4 types of dampers (mono,bi,tri and treble), can you tell us how each of those work?
MV: The shape and the types of dampers depend on the string they are supposed to damp.
A – The “Mono” or “One string” looks like a square with a V shape inside in order to envelop the large string on bass section of the piano.
B – The “Bi” or the “Two strings” looks like a V shape in order to get inside the space between the two strings on the tenor section of the piano.
C – The “Tri” or “Tri strings” looks the same as the “two strings” wedge shape but contains a split in the middle to act as a double wedge. These are for the lowest plain wire strings.
D – the “Flat damper” looks like a cushion of low density felt and are used for the highest notes on the piano.
For all dampers the target is to damp the sound, that means that they are in charge of absorbing the vibrations of the strings. Those vibrations are in fact frequencies like sinusoid signals (pictured above). The bass notes have low frequencies which mean long and spaced sinusoidal waves, and on the contrary, the treble or high notes have high frequencies which mean shorts but repeated sinusoidal waves.
Of course, for playing the piano, it is interesting to have more or less the same time to dampen the sounds when you release the keys, wherever you play on the keyboard (bass, tenor, or treble) and yet the frequencies and subsequent energies are quite different. For achieving that, we use different dampers with different properties adapted for the frequency of the sound. On the treble section, frequencies increase drastically when you play more to the extreme treble section. So for this section, even if there are 3 strings for each note, we have to change the method of damping from the double wedge to the flat block dampers.
GB: Is there a certain density of felt that is ideal for piano dampers?
MV: Yes of course there are optimal densities for dampers. And there are also certain densities depending on the placement inside the piano (density for bass and for treble felt are different). Ideally the density should be as low as possible. You could find on the market bass dampers with densities from 0.23 up to 0.35 and for treble dampers ranging from 0.14 up to 0.25. Physically, density is weight over volume (D = W/V). For the felt manufacturer the challenge is to make low density felt because it has superior damping properties however it is much, much more difficult to produce. In order to be able to cut them with a high degree of precision (1/10 a millimetre) the felt should be perfectly consistent otherwise it is impossible to cut. The challenge is also for piano technicians, it is much easier to work with “hard” dampers when you do not have the correct know-how and experience. A soft felt is difficult to make on several levels: First, achieving the felting process for low density is very difficult, because if you are under the good “felting point” (felting being the intertwining of fibres), the middle of the felt will remain as only wool if it is not felted. And if you are over the optimal felting point you are too hard on the surfaces and soft in the center and thus, the felt is not consistent.
The job consists of making felt the same from top to bottom. This is not easy. It takes much more time, involving more hands-on processes and also involves a lot of waste. That is why it is more expensive than denser felt. Ironically, you pay more even if there is less wool inside because it is much softer but contains greater damping properties.
GB: In the cullinary world, it’s kind of like baking the cake right? Too hot and you burn the outside, too cold an oven and the center doesn’t get cooked. Interesting. Speaking of damping properties, what makes for great dampers? And can you take us through the manufacturing process a little?
MV: Wool is the first and natural technical fiber with a “form memory”. The felt pressed against the strings absorbs string vibration. If you leave the felt released, the impression will erase. This is what makes great dampers. The softer the felt, the better the form memory. Making great felt requires technical know-how but also great raw materials. Normally felt is graded by 2 criteria: the quality of the wool used and the density. We buy the wool taking into consideration the length of the fibers (told in millimetres), diameter of the fibers (told in microns), and ability to felt more or less (the curving of the fibers). Of course the thinner and the longest fibers are much more expensive than the shortest and the biggest fibers.
A – Wool opening and Blending: we make a blend of wool with different single lots in order to have something always the same. With blended wine for example, you assemble different qualities with more or less the same proportions to create consistency. If we were using only one type of wool for each production, we would have different results from one production run to another and so good blending allows consistency in production.
B – Carding: the blend goes into the carding lines in order to create wool layers. With our machines we can adjust the weight by square meters of the layers, and also the fiber direction (crossed or not).
C – Composition: It is a hand made process consisting of assembling and cutting several wool layers depending on the final result we want to achieve. In short, we know the final dimension and density we want. We will use the right weight of wool at the right dimension taking in consideration the shrinking coefficient we will apply.
D – Felting: The transformation between wool to textile. It is a natural process (no chemicals involved) where the fibers are matted together via friction.
E – Fulling: Once we transformed the wool layers to felt, we have to shrink it to it’s final dimension in order to give it it’s right density. This is again a hand-made process, one piece at a time. Dimensions of the felt should be controlled because we need to keep consistency in the shrinking. The right density is obtained when the felt is at the right dimension, not before, not after.
F – Drying. The previous process of felting and fulling require moisture and so the felt must be dried.
G – Pressing: Here we calibrate the thickness of the felt, for example 10.2 mm thick. We use hot presses to achieve this.
H – Finishing: Depending the product we make it goes to the dedicated workshop in order to be cut or assembled to its finished purpose.
GB: Aside from piano felt, what other applications do you make felt for?
MV: There are many many different applications for felt. Felt is used for its natural properties of absorbing, transferring and sealing. Some industrial fields using felts: writing instruments, railway, automotive, nuclear, tools, bakery, design and of course, piano making.
Glen Barkman: Wow that was a fantastic glimpse inside the world of felt making by Laoureux. They are located in Normandy, France and operate in 7,000 m2 facility (about 75,000 ft2 factory). A special thanks to Marc for his expertise and continued dedication in providing the world with quality felt.
Have you ever heard of the company called Estonia Piano? Appropriately they are named after the country in which they reside. Haven’t heard of the country of Estonia? They gained independance from Russia in 1991 and eventually became part of the European Union. Situated across the water from both Finland and Sweden, Estonia has been actively making pianos since 1893. This month I had the wonderful pleasure of skyping Dr. Indrek Laul (CEO of Estonia Piano). Although we’ve only met twice in person, he is a pleasure to converse with and if you could only sit where I sit, you’d find that his passion for piano building shines through. But he not only is passionate about piano construction but piano performance, having obtained his doctorate from Juilliard School of Music. You can see his fantastic ability on youtube here. The following is a wonderful illustration of piano design that weaves old concepts into new told by Dr. Laul himself. Enjoy!
“I was on a flight from Houston to New York reading this article from Wall Street Journal about billionaire Larry Ellison regarding his passion for competitive sailing. On these giant catamarans Team Oracle (funded by Ellison) had been failing against Team New Zealand despite having high tech computer sensors generating 3000 variables 10 times per second. The computers predicted the most efficient path for tacking (zig-zagging across the water against the wind). All indicators predicted victory to this high tech team and yet they consistently lost. Watching the video replays of both boats, they found that their competition – team New Zealand was tacking at a much greater angle making them go farther distances but at greater speed. When Team Oracle tried this, in the end it was discovered this “low and fast” method was superior and ultimately led them to victory of the America’s Cup. Although the computers aided much of the efficiency for Team Oracle, the last step towards the finish line, the final stretch came from sailing intuition ~ intuition which had been passed down for generations. Segue.
When it came time to design two new models for Estonia Piano we decided that our starting point should be listening – listening to pianos that really moved us. Invariably the pianos that provided inspiration from the late 1800’s/early 1900’s were the ones that captivated us.
Similar to the sailing example, “the final stretch” came from pianos that didn’t have technological advances. Sometimes we need to set aside what could be deemed most logical in order to ‘experiment with joy’. We wanted to capture anew and to relive the excitement and joy of beautiful tone and in doing so we started with these living examples from yesteryear. We then examined them and found that there was a common theme in soundboard construction which had major ramifications. The soundboard acts as an amplifier to the strings. There has been this movement towards tapered soundboards meaning that they are made thinner as they approach the rim (see diagram).
The reasoning is that this gives the board more flexibility to vibrate. Paradoxically however, the older instruments we listened to and enjoyed didn’t have tapered soundboards at all and yet we enjoyed them more. They were more rigid. This newer movement with tapered soundboards which vibrate freely, can also be problematic in being unwieldy and so to compensate, more perpendicular ‘ribs’ on the under side of the soundboard are used to stiffen it in the center. Well if you have a firmer soundboard like the pianos from last century, it requires fewer ribs. Fewer ribs reduce rigidity and rely more on the soundboard itself. So in simply redesigning the soundboard, automatically it required the spinoff effect of redesigning the amount and configuration of the ribs. I know this is technical, but ‘experimenting with joy’ can be exciting when you hear the results.
So we found that if we made wider and shorter ribs – having the same mass as previous ribs except the older ones were thin and tall – we achieved better control of the soundboard. There is also a movement to placing “pre-crowned” or slightly arced ribs on a crowned soundboard. Makes sense correct to match the arc of the ribs with the arc of the soundboard? On the contrary, we discovered that flat ribs pressed adjacent to a curved soundboard created tension. This tension resulted is in an even livelier yet stable soundboard.
But we didn’t stop there. In these new design changes, we also examined the contact point of the bridges. We found that bevelling the edges were more conducive to sound transference. The ‘less is more’ idea works well here where less contact on the bottom edge of the bridge achieved maximum transference with the least amount of soundboard interference.
Finally, we re-examined the beam structure underneath the piano. With 20 tonnes of compression from the strings, we experimented with the beam structure to match that pull by placing beams in a radiated fashion to create an equal and opposite rigid design. What started with the concept of listening, abandoning any pre-conceived ideas and then re-engineering, it led us down this path of two new pianos which we are really pleased with. We are now actively implementing these concepts to the rest of our models.
Oh and to finish the story about Larry Ellison, shortly after that race he purchased a brand new model 210 Estonia grand.” ~ Dr. Indrek Laul.
This is such an exciting story – one that ties in modern piano construction with artisan design concepts. A special thanks to Dr. Laul for this captivating illustration. You can view all of the current Estonia models on Piano Price Point here.
Stephen Mapes established the Mapes Piano String Company in 1912 and shortly thereafter in 1918 it was purchased by John Adam Schaff. Now 4 generations later and employing 125 people in a space of 200,000 square feet, Mapes produces piano wire for many of the pianos we play on today. This month I had the pleasure of sitting down with Andy Wilson from Mapes to discuss some of the basics of piano string making.
Glen Barkman: Mapes is the oldest piano wire maker in North America. How old is the Mapes company?
Andy Wilson: Mapes is not only the oldest but the ONLY piano wire maker in North America. Established in 1912, our company is 103 years old this year.
What exactly does Mapes manufacture?
Mapes manufactures piano wire, spring wire and specialty wire.
My division looks after piano wire. On any piano you’ll see that there are 2 different kinds of strings. The top 2/3rds of the piano are plain steel wire that we manufacture. Just by looking at them with the naked eye they look the same but there are actually many different sizes of wire on a piano. The bottom 1/3rd contain strings with a steel core wrapped with copper to make the lower tones of a piano. Mapes manufactures both the plain steel wire as well as custom bass strings for pianos.
Both the steel wire and the core of the bass strings are drawn wire correct? Can you tell us a little about the drawing process?
In order to make great sounding strings you need to start with good raw material. There are over 3,500 grades of steel. We have a steel mill that makes high grade steel to our requirements. So to begin with, you need to specify the chemistry – one of our closely guarded secrets. Before getting into drawing wire, it goes through a process called austenitizing where we heat up the steel to 2000 degrees and then “quench” or cool it again. This changes the structure of the steel.
We then press the steel through a funnel which is also called a die. It is pulled or drawn through the die where each time it reduces in diameter by as much as 30%. Think of steel like a piece of wood. Wood has pores or grain. Each time the steel gets reduced, the grain or fibers also get compressed. Heating opens up the “grain” in the steel while the cooling process stabilizes or sets the structure of the steel. So in piano wire making, there are at least 3 heating occurrences and 4 drawing processes to make the finished size.
In your opinion what makes for a great piano string in terms of singing tone?
There are three elements which make great piano strings – First you need great raw material. Chemistry is so important. Second, you need perfectly round wire. And third, when making bass strings, you need correct and consistent tension of the copper wrapped around the steel. Without these 3 necessary components, you could end up with unwanted vibrations which can lead to an inferior tone. Out of shape roundness causes distortions. In order to make a piano string vibrate freely, our job is to manufacture in such a way that it does not interfere by having any anomalies. When the hammer of a piano strikes that string, the vibration moves up and down the wire. Any interference alters that tone. So it’s our goal to make as round and as pure of a string in such a way that it does not obstruct or alter that vibration.
How many sizes of treble piano wire does Mapes offer?
We make sizes from 12-22 in half sizes (12, 12 ½ , 13, 13 ½ etc) and then 23-27 in whole sizes. So we make 25 different sizes of piano wire. Each size is one thousandth of an inch (about 0.025 of a millimetre increments) – approximately one third the thickness of a human hair with tolerances of 3/10ths of one thousandth.
The history of drawn wire seems to have been established in about 1840. With technology, how has the process been refined or made more efficient over the last 175 years?
Over the years, the raw materials have definitely improved. But within our own company, the basic premise is the same but what have changed are the controls. So instead of simply heating up the steel, we have accurate sensors and controls that are indicating more precise measurements of temperatures, tolerances, speed indicators and cooling controls.
Are piano wires ever coated at least to prevent corrosion or does that interfere with tonal properties?
Nickel electroplating is actually the finishing step of piano wire for silver look. That might create some corrosion prevention but electroplating is only microns thick. Some think it’s polishing but it’s actually electroplating. Any piano wire however will rust over time because that’s just the nature of steel. When it comes to copper coatings in the bass, I have not found anything relating to coatings that doesn’t affect tone.
How are bass strings made?
Bass strings are a combination of steel and copper wire. The addition of the copper wire adds mass to the bass string for depth of tone. Correct tension during wrapping stage requires consistent tension. Copper compacts somewhat when wrapping and pulls down in diameter and so uniformity is everything.
When you look closely at bass strings where the copper terminates there is a flat part. What is that?
The flattened portion is called a “swedge”. Since the center steel core wire is completely round, the copper wrapped around it needs a place to attach so that it doesn’t slide up and down the core. If you flatten the steel at each end it gives the copper something to bind to.
Large bass strings are often double wrapped with 2 layers of copper. What is the purpose of double wrapping a piano string?
The purpose of any wrap is to add weight to a string. The weight gives more depth to lower notes. Generally, the shorter the length of a piano, the more you need copper to add weight to a string to get those low vibrations. Conversely, the longer the piano, the less copper you need for lower tones. If you want a lower tone, you can have either a single large copper wound string or 2 smaller copper wraps to achieve the same mass. There’s a lot of debate – some manufacturers would like single wound strings while another might do 2 small wraps. We simply make custom strings to the manufacturer’s specifications. Those decisions regarding double or single wraps are part of the “scale” of a piano that are made at the design level.
I just wanted to thank Andy Wilson for giving us a few insights as to the industry of making piano strings. There are very few companies globally who have the capacity to make the quality with tolerances as fine and consistent for piano making. Congrats to Mapes for continuing this pursuit of excellence for over 100 years.
To learn more about Mapes Piano String Company, you can find their contact and ordering information on their website: Mapes Strings
The Mapes Piano String Company
#1 Wire Mill Road
Elizabethton, TN 37643
Behind the scenes in the piano business it’s a very small world. You won’t last but 10 minutes before you hear something about Abel hammers. Hammer heads – the felt that strikes the strings on a piano are in my mind the most critical foundation of tone. Abel is world reknown specializing in hammer manufacturing. It was my pleasure to meet Norbert Abel last month and have him shed some light on the piano hammer making proccess. Every time I interview someone I learn something new about the piano trade. Although I’ve been in the business for just over 20 years, I only now have heard 2 words which were unknown to me before this interview: Lanolin and Biofelt. Read on to hear the words of Norbert Abel. And by the way… Abel makes about 50,000 sets of hammers per year… multiply by 88 keys on a piano that equals 4.4 MILLION hammers annually. They are arguably one of the greatest authorities on hammer making in the world.
Glen Barkman: The History of Abel – How did you come into this business?
Norbert Abel: My father, Helmut Abel started his own hammer production business in the year 1982 after he had worked for another German manufacturer making piano hammers and action parts for 23 years. His goal was to produce hammers in the ‘old style’ which meant custom making hammers for each manufacturer using high quality materials and advanced techniques.
All pianos are different and have individual requirements and so with this custom approach, he convinced many of the piano makers and technicians with the Abel quality and philosophy; making hammers for many brands to individual specifications.
From the beginning I have been involved in the business side and have seen the continuous growth and development of production. In 1988, my brother Frank started into the business and has taken over production. The third generation, my son Alexander is now learning step by step the difficult procedure of hammer making. Since 1993 the Abel Hammer Company has a factory in Frankenhardt, Germany. In our history, our facilities have increased two times now to 24,000 square feet of manufacturing space with an annual production of over 50,000 sets of piano hammers per year.
What are the steps in making hammers?
Hammer making looks to be very easy: Take some wood, some felt and put both into a hammer press and the hammers are finished. But it is not that easy. The whole procedure is much more complicated.
Everything starts with the felt. Felt is a natural product and based on Merino wool (Merino is a type of sheep with incredibly fine and high curled fibers) from South Africa, New Zealand or Australia. In these countries the Merino wool will be selected into different grades. For making hammer felt only a high grade wool fiber can be used. Then the raw wool comes into a cleaning process to Europe where all dirt, sand, dust, mud, vegetarian parts are washed out. This process is called carbonizing under the use of sulphuric acid. However, this acid is counter productive to hammer making as it has the undesired effect that a lot of natural lanolin will be also washed out (and the acid also is not good for the environment).
Natural lanolin (also called wool wax ) is very important to keep the natural resilience in the hammer felt which greatly affects piano tone. To retain this lanolin, Abel started the BIOFELT PROJECT 2003-2006 (sponsored by the European Union) with the result of a felt called NATURAL FELT which did away with harsh chemicals in the washing stage of felt making. This is a more natural product – not as white in color but incredibly versatile in sound. The use of this new Abel Natural Felt is responsible for great success in the piano business in our company.
Felt sheets will be then cut into strips after the sheets have been carefully controlled. The single wool fiber is still in a curled position. In the hammer press the felt will be pressed around the hammer moulding to stretch the wool fibers and to build up the resilience in the hammer felt. This procedure is the main secret of the hammer production. All hammer makers have a slightly different philosophy with this. Here is where Abel’s 55 years of experience in hammer making from Helmut and Frank come into play. Understanding the whole process from “Sheep to Hammer” is the basis of the high quality Abel hammer production.
Although we have our own brand of felt, we also incorporate other felts from other makers to give a wide range of choice so that each maker can select hammers suited to their needs and guarantee the Abel high quality standard of manufacturing.
What’s the difference between cold and hot pressed hammers? How does that affect the hammer head?
Cold pressed means that the felt in the hammer press form will be pressed with no heat or almost no heat. This guarantees that the natural resilience of the wool fiber will be kept alive. Hot pressed hammers in a heated press stabilize the wool fibers however it means that the natural resilience is gone and the hammer felt has lost its elasticity and the ability to create a maximum range of sound colours. The Abel hammer production is a cold pressed process for this reason.
Why are hammers measured by weight? (for example 16lb hammers)
Hammers need a different weight because the pianos are different in size. The bigger the piano, the more weight is required to bring the long strings into vibration and to create maximum sound. For this reason especially the weight and size of the felt are important. A big hammer has a lot of concentrated resilience in the felt to stimulate the string to maximumize sound producing energy.
How does the wooden moulding material affect the hammer?
Different hammer wood is important for different weight. Especially big pianos need larger felt with light hammer mouldings. The large felt is important to maximumize sound vibration and the light woods like walnut and mahogany keep the total weight on a level which makes piano playing possible. So if you combine large felt hammers with light wooden mouldings, the overall weight is manageable at the keyboard.
What is the purpose of underfelt? Do colours designate manufacturer or something of function to identify a design or a time period?
When the first hammers were built the hammer makers did not have the same size felts available that we have today. It was necessary to make a hammer with different layers of underfelt and a thin top felt outside. Nowadays, we can make the same size of hammers with one layer of underfelt and a midsize topfelt or with no underfelt and a big size topfelt. The quality of the underfelt is always the same. But the underfelt can be dyed with different colours to show different brands.
How does quality of felt affect tone? Within one sheet of felt there might even be discrepancies in tone, correct? What felt does Abel use?
We use various felts from different makers. Different felt manufacturers each have a ‘signature’ in the type of felt they make. The combination of felt and felt making procedures will result in different sounding hammers. In this way hammers can be individualized for customized requirements. Felt is a natural product. There are natural discrepancies within a sheet and from one sheet to the next sheet. It depends on the ability of the hammer maker to realize these discrepancies and to select the felt strips. Abel has skilled people who test all felt strips by hand and with their experience they select the strips in to different grades like soft, medium or hard. We call this the “outside quality”. The inside quality depends on the different raw wool and manufacturing process of felt in the felt factory. That means the inside quality describes different characteristics of felt from different felt makers. At Abel we are always in discussion with our felt suppliers to keep the inside and outside quality of the felt sheets within an acceptable quality range. Abel is in contact with all hammer felt manufacturers worldwide which allows us to always select the right felt for our customers and retain diversity.
Density of felt also produces really different results. Is there a way of determining sound from a certain hammer from density and/or elasticity?
The density can vary from one sheet to the next sheet and also within a sheet. As long as the density is within the tolerance of the Abel specification the felt can be used in the Abel hammer production. Density of felt sheets can be determined with the felting process, the milling process and a pressing process. Most important is the felting and milling which enables the wool fiber to interlock and to build up a system of fibers with a maximum elasticity when the felt becomes pressed around the hammer moulding. This complicated procedure has a big influence on the sound of a piano. A hammer with a lot of resilience and a lot of natural life in the felt can create a wider tonal range. The best felt to reach this goal for our production is the ABEL NATURAL FELT. Hammers with less resilience and stabilized wool fiber do not have the ability to create such a wide variation of tonal colour at the piano.
I just want to say thanks to Norbert for allowing us a small glimpse into the art of hammer making. In addition to manufacturing of hammers, Abel also performs operations related to hammer customization called shaping, coving and tapering. Of interest to some wanting to preserve a vintage instrument, Abel also has the capacity to re-felt hammers on existing mouldings. This keeps the wooden shanks and flanges intact and keeps the authenticity of the instrument. Amazing! Hope you enjoyed this interview as much as I did.
Earlier this year at NAMM I interacted with Mr. Hailun Chen – truly a privilege and honour to connect with such a humble visionary who has influenced and supplied more piano parts than we’re probably aware of. I greatly respect individuals who state “I have put my name on my pianos and on my company”. Mr. Hailun Chen is the real McCoy where his name is his guarantee.
Working with a translator, he showed me different concepts in his pianos. What caught my eye was this silver looking gleam under the keys on one of their upright pianos. As seen in the picture, the key “bed” is the horizontal frame that the keys rest on. It’s imperative to have a solid key bed without which the piano touch would be compromised in evenness and functionality. Normally made out of wood, frames will sag or warp over time. It’s a common problem.
Aluminum however, prevents this problem and ensures both structural integrity but also alignment for a life-time. It is completely warp resistant. So if the strings run vertically in an upright piano, the key bed is perpendicular to the frame. If there is any sagging or warping in a wooden key bed, even by a few millimetres (1/16th of an inch), the problem is compounded in the vertical alignment of the strings.
So what are the implications of integrating aluminum? (See? I knew you would be as excited about this innovation as I am. This innovation BTW is exclusive to Hailun pianos and is officially called PAS system – Permanency- Accuracy- Stability). Well to keep any piano completely in ‘check’ and performing optimally, regulation (fine adjustments) are done. Quite often, as pianos age and get worn, piano technicians are making these adjustments to compensate for worn parts but also for a sagging key bed. What happens then if key bed issues were taken out of the equation? Indeed, the regulation would be a much easier task. Speaking with Basilios Strmec, CEO of Hailun Distribution for North America, it gets even better. Let’s say you are an avid pianist working hard on a performance degree and you used one of the Hailun pianos as a workhorse. You would expect to see substantial wear and tear, correct? Over years, when pianos start to feel and sound worn, if you had an aluminum key bed, you could simply swap actions and renew the instrument to its original condition.
That means in essence you would have a mechanically NEW piano – with new joints, hammers and parts. It would feel new but also the fresh felt on the hammers would make it sound new. Historically during construction of a piano, one instrument’s parts were fitted to just one piano – meaning they’re not interchangeable. Even if it’s the same make, same model, same brand, same year, you would usually not be able to change out parts readily. With modern computer based CNC (Computer Numerically Controlled – in other words carving out parts by computer control), the precision is such that you could actually swap out the ‘engine’ of the piano with 4 bolts in a few minutes. In essence then, we’ve reached an age in manufacturing where not only are you investing in the present piano but saving on the rebuilding costs for years to come. That’s amazing! Kudos to Hailun for the innovation in the industry. Special thanks to Basilios Strmec for taking the time to discuss this with me and providing information.
Haven’t heard of Hailun? They have over 430,000 square feet of manufacturing space and employ over 1,100 people and one of only 2 Chinese made piano companies listed on the Shenzhen stock exchange.
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