Posts tagged bridge

Horizontally Laminated Bridges

I will go to my grave arguing that horizontally laminated bridges are the WORST thing possible on a piano. Sometimes my blog is informative while today i just need to rant. Yesterday i tuned a brand new piano (which will remain nameless) and i thought to myself – i’ve tuned pianos that are 100 years old that are better than this #$%[email protected]#. What is WRONG with this piano???? So i guess a wee bit more description would help: It was a continental style upright. Continental means it has no front legs and is rather narrow front to back. Rather narrow usually means short key sticks. Short key sticks means it usually doesn’t feel very balanced. Check mark. Then i noticed that the dampers were lifting AHEAD of the hammers. WHAT???? The damper blocks dampen the sound and should be removed from the strings about halfway through the key stroke. Instead, they were lifting BEFORE the hammers were even moving. Ridiculous! In addition to lifting at the wrong time, the damper springs were so heavy that it made any kind of delicate playing impossible. OK wait… there’s more. So about 2 octaves above middle C, the tone just decided to take a left turn and sound like a tin can on steroids. But the Pièce de résistance in this piano was the lack of sustain. I took one look at the bridge (pictured) and added it to my list of bad pianos of all time. I have NEVER NEVER NEVER played a piano regardless of name brand that has a horizontally laminated bridge. WHY? Because sound will not travel through 14 layers of glue. FOURTEEN!?? Yep. Fourteen. I counted.
So if you have no idea what i’m talking about, a bridge (like that on a guitar) is the part on the piano where the strings transfer energy to the soundboard. If you look at the picture, you’ll see the strings crossing over the bridge pins onto this piece of wood. In this cheap piano, they made it out of layers and layers of glue… errr i mean wood. It is my experience that bad bridges are bad for business. The pianos ALWAYS sound terrible.
Now i understand the need for cost effective manufacturing and maybe this is my ignorance in woodworking but if you need to make a cheap bridge, why not turn it 90 degrees and do a vertically laminated bridge so that the sound is running down the individual strips of wood? The big boys (those who build $100,000 plus pianos) usually have a solid one piece with a cap for structural integrity resulting in great transference but also crazy costs. But i’ve also played really great pianos with 5 ply vertically laminated bridges. That is my guess at why i can play a 100 year old Bechstein that sounds wonderful (on today’s list of tunings) and why this piano that is brand new plays like dirt. Manufacturers need to wake up and realize that if there are corners to be cut, tone is not one of them. This week a piano tech said to me “The road to hell is paved with shortcuts”. Truly this is one of them.

Piano Bridges

Bridges are beautiful aren’t they? And true to form, they serve the purpose of connecting – of filling the gap.  Many know what a bridge is on a guitar or violin but many do not know of piano bridges.  What is the purpose of the bridge anyway? Well simply put, the bridge transfers the vibration of the string to the soundboard where the tone is amplified.  So the EFFICIENCY of transfer is critical to retain the sound produced at the string.  Effectiveness comes from 5 elements and they are:

Position – if the bridge is positioned on the soundboard incorrectly, the tone will be compromised

Material – many are made from maple or mahogany

Downbearing – how much pressure is being placed on the bridge by the strings

Notching – cutaways leading up to the flat surface on top

Laminations – most bridges today have at least a “cap” which is a cross laminated piece to reinforce the bridge for structural integrity.

When bridges go terribly wrong… most people when purchasing a used piano don’t look for cracks in the bridge.  They ALWAYS look at the soundboard but quite often don’t consider the bridges.  If the bridge is cracked, the tone “bleeds” from one string to the next and will not have any substantial sound or sustain.  The other thing which i will point out is that inexpensive pianos have a gazillion laminations (it looks like plywood).  I swear there’s more glue on some of the cheap pianos than there is wood.  I’ve NEVER heard a GREAT piano with more than a few laminations.  If you see one with 10 ply or more… take note to the sound.  Chances are, the tone is also very comprimised. 

On a completely different note, at a recent trade show (NAMM 2011) Petrof introduced a redesign of their spectacular grands and interestingly the bridge at the very high notes on the piano is BLACK! That’s because it’s made out of ebony – which they claim makes excellent transference of high note tone. I have to confess… it was a favorite piano to play when i was there. Beautiful.

When in doubt just say “Duplexing”

Duplexing just sounds complex. Complex means it’s complicated. Complicated must mean that you’re somehow smart. And so… (follow the trail) knowing about duplexing means you’re smart. Ha ha. If you’re ever at one of those hors d’oeuvres-type parties and everyone’s dressed in tuxedos and ballroom gowns, you’re going to want to have something to say when they ask your professional opinion about the piano. My advice? Nod… add a few “mmm-hmmmms” and say “Ahhh… Duplexing”…hee hee. Ok enough of my jesting…

So what exactly is duplexing anyway?? Created by the late great Mr. Steinway himself in 1872, it was designed as an ‘added ring’ to pianos – giving more resonance to the tone. How is this accomplished? Glad you asked. Any piano string has what is called ‘speaking length’. This is the live portion of the string which resonates freely when a note is played on the piano. The speaking length starts just past the tuning pins on a part called an agraffe (or capo d’astro… ok i’ll define those some other time) and ends on the bridge. Past the bridge, the string is then wrapped around some sort of termination pin. The tone past the bridge was traditionally considered ‘dead’ tone. But Steinway thought “what happened if we kept this part of the piano ‘live’ or ringing in harmonicity with the instrument”? And so the duplex system was born. Think of it as duple time… duple by definition means ‘double’. So duplexing then is a double ringing part on the piano. How did Steinway make this contraption? He rigged another ‘bridge’ just before the termination point. One that was made out of a series of bars. In fact, if you want to test out the duplexing on your piano (if you have it), simply look past the bridge (which is easy to see on a grand piano) and you’ll spot the parts that are called “Aliquots” (another great party word after you’ve used duplex). You can test how live the duplex is on your piano by simply strumming that portion. An aliquot on a piano is a bar shown in the pictures here. By definition it means “fractional part”. Stands to reason… since we’re adding a fraction of the sound to the tone. In Latin, it simply means “several” or “a few”. Steinway’s thinking was to add either an octave or 5th to the existing tone, making it fuller and richer sounding.

Having said all that… some people just don’t like the extra ring. Solution? Simply cordon off the strings with what is called ‘understringing braid’. (I know i know… too many new words this time around). In the tech world, it’s simply called understringing – anything touching the strings will stop the extra tone and so if you have a technician ‘block’ the tone by adding understringing, it will alter the added ring on a piano. By the way, one experiment i did about 5 years was change the proximity of the understringing with the bridge. It changes perceived tone considerably.

The Best Time to Tune

First of all, let me say that if you haven’t had your piano tuned in YEARS, the best time to tune is RIGHT NOW.  This article relates to people who tune their pianos regularly and would like to know how to optimize their tunings so that they last longer.  (and i just heard someone say “You can optimize tuning???”) The answer is a resounding YES! But before i give you the goods on that answer, i’ll keep you in suspense and drag you through the proverbial mud on the why’s of this answer first.

There are 3 elements that affect tuning stability.  Tuning pin torque, stretch in piano wire and soundboard fluctuation. Tuning pin torque has to do with how tight the tuning pins are in the pinblock.  For those who can’t place what part i’m talking about, these are the steel ‘pegs’ the tuner loosens and tightens to tune the piano.  The wire is stretched across the piano and are wound around these at either the top of the piano (on an upright) or at the front (on a grand).  Tuning pins are held by friction in a pinblock – a wooden (most often laminated) block of wood which i found out a few years back is called a wrestplank in Europe.  The word ‘wrest’ has its origins in ‘wrench’ which makes perfect sense really.  It is the part of the piano the tuner uses the tuning hammer (or wrench).  So if the friction is not there, the torque is not there and there will not be tuning stability.

The second factor affecting tuning is the steel wire itself.  Now this only applies to new wire.  Believe it or not, there’s HUGE amounts of stretch when new wires are installed on a piano.  Generally, i’ve noticed that it takes about 5 tunings to get new strings to stabilize.  If you’ve EVER had one broken string on a piano, you’ll know that the new wire will go out of tune quite quickly for the first few tunings.

So if your piano has good tuning pin strength and the wires are not new, that only leaves one alternative as to why pianos go out of tune on a regular basis (remembering that there are 18 tonnes of pull constantly at work as well!)  The last factor affecting tuning is the fluctuation in the soundboard.  The soundboard is the giant ‘amplifier’ that takes string resonance and multiplies the volume.  Without soundboard there is little sound on a piano.  Now similar to a guitar, the strings of a piano cross over the bridge which is directly attached to the soundboard.  Since the soundboard is dynamic – meaning that it is constantly moving, fluctuation in tuning will occur.  And what affects the soundboard? You guessed it, humidity.  Humidity affects wood CONSTANTLY.  It absorbs moisture and swells and dispells humidity and shrinks.  There is a constant contraction and expansion of the soundboard. 

So back to the question: When is the best time to tune the piano? The answer: after the major adjustment in humidity has occurred – namely spring and fall.  In the fall, the humidity shifts into the rainy/snowy season and in the spring the humidity moves into the dry/sunny season.  As soon as that shift has taken place, the piano will then be adjusted for the next 6 months.  So what happens if you tune before that time?  Well, you’ll nicely get your piano tuned, the humidity will shift and then you’ll notice notes will start to sound a little bit ‘out’.  To optimize your tuning, wait until AFTER the shift.  Where i live those months are October/November and March/April.  Just a thot to make your hard earned dollars last a bit longer…

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