String Design and Manufacture

Most modern strings are made with solid or stranded metal or synthetic cores covered with wound coils of wire. (see the first two  photos for examples). The native quality of sound  produced by such a construction is the result of a precise design balance between the materials chosen, their dimensions, densities, elasticities and other physical characteristics in combination with the  manufacturer's  chosen assembly method and control of process variables like winding tension and twist.

GrimeTheory :

Wave Overtones Good-Bye

New strings have an even distribution of mass along their playing length. When a clean new string is sounded, a Helmholtz wave is generated which happily travels unimpeded back and forth between the  bridge and the nut. The Third photo shows a similar wave propagating down a string. The un-shown return waveform would be a mirror image but with the wave crest flipped over on the bottom. This wave acts in combination with the physical properties of the string, the instrument and our playing technique to create an overtone series and a set of standing waves along the string's length. Taken together, this creates what we hear. The Fourth, Fifth and Sixth photos show such standing waves on a bass, violin and a viola. You can see this going on for yourself if you look closely when someone else is playing on a low string: if everything aligns with your eye  just right, the waveform on the string will seem to stand still during a long bow stroke. Things sound good if we have done our part in activating the string correctly, the rest of the strings are clean and the resonator (the instrument) is in order. Over time however, the physical condition of the string begins to degrade as rosin, body oils, skin cells, sweat salts and other debris like microscopic pieces of our favorite deli's pastrami sandwich are deposited on the surface. Good cleaning habits (wiping down the strings after each use) remove some of this material, but over time little deposits of gunk build up on the string surface and more importantly are pushed down between and even under the windings where your cleaning rag can't reach. The seventh  photograph taken here in the lab shows deposits still left remaining on a string after it was wiped down carefully by a highly trained technician at StringCleaningTM. The debris left behind is both on the string surface and fills some of the grooves between the windings. This collected gunk changes the local mass of the string at points along its length. Mass distribution on the string has a strong effect on your sound. This additional mass is one reason why you find that old strings require a little more tension to bring them up to pitch. However, the worst part of this slow change in string mass is that this gunk isn't evenly distributed along the string's length. Instead, it mostly sits in little clumps of irregular additional mass where we put down our fingers or where we bow. Our Helmholtz wave no longer can freely run up and down the string. Instead, it has to navigate a series of tiny speed bumps on the string caused by these little additional clumps of mass. Each clump disproportionately saps high frequency energy from our beautifully formed original pulse and causes a mini reflection of ugly sounding out of phase energy backwards from the direction of pulse travel which will interact with and muddy the next beautifully formed pulse we work so hard to send down the string. The eighth image shows a wave hitting a single one of these speed bumps represented by a dark heavy line. You can see the little unwanted rogue wave heading backwards and a reduction in the amplitude of the original wave as it travels over the bump. Imagine the additive effect of a series of these speed bumps. Sonic disorder and tonal destruction! As these deposits only increase with time and use; the strings' overtones degrade, highs are muted, the native ability to sustain is reduced and the string may speak more and more slowly. When the disorder  reaches a level beyond our skillful control, the individual string sounds dull and old when played. Sadly, this residual grime's affect on our sound doesn't stop there. We all look for our instruments to ring, and this little joy comes to us in large part through the unimpeded sympathetic vibration of the other unsounded strings. If these strings are dirty as well, their sympathetic vibrations are damped which then affects overall timbre and reduces the ring we hear as we play.  Overall tone quality degrades, pitch gets tougher to control... sustains get harder.....voicing the string gets tougher........time for new strings right?  No....time to try a deep cleaning first before spending the big bucks. Put on some spare strings one at a time and send the old ones to us for cleaning or better yet take an old expensive set you have laying around and ship them off to us and leave your current strings in place. We'll get the old set back to you quickly, cleaned and ready for mounting and end your misery at a reasonable cost. The ninth image shows a cleaned old string. Notice how the surface is bright and the grooves between the windings are free of gunk. That is the mechanical appearance of good potential sound in an otherwise sound string. The rest is up to you.

Note to Physicists and Audio Engineers:

By now you have noticed the absence of differential equations and other mathematical ephemera in the explanation offered above. That's because the  preceding is meant to create a first order understanding of the system for the average musician. Because it is a simplification, it is by definition inaccurate. Please don't pillory our well intentioned attempt at describing what is going on in terms of popular and understandable Physics, it will hurt our feelings and probably not advance the worthy cause of cheaply resurrecting good sound from the sonic ashes of old strings. But if you like, we can retire to academic mode offline and delight one another with a mathematical tour de force filled with partial differentials. As an aside, since you are the customer, we will certainly be differential and partial to your views. On a serious note, if you are interested in researching the subject in more depth, we can provide a good starting bibliography for study and discussion since we have done the research and the testing. Just drop us a line at mailto:info@stringcleaning,com

String Cleaning Tips to Delay the Inevitable

Here are some thoughts on  delaying the need for our services and further extending your string life.

Daily cleaning of your strings with a soft microfiber rag will extend string life and support good sound. (Microfiber cleaning cloths are cheaper at the auto parts store. These are also large enough in most cases to cut into sections leaving one piece for the instrument case and one for the practice room) Wipe strings down at least once a day; more if its needed based on playing style or what well seasoned delicacy you had for lunch. If it helps form a habit, make wiping down your strings a daily religious act: say a prayer for all poor musicians living and dead as you wipe.

If you are an  adventurous, skilled and careful person, you can also clean your strings once a month or so with a bit of solvent to more aggressively dissolve gunk. Alcohol (the rubbing variety, not grandma's Remy) works well and doesn't leave much residue behind. The little alcohol swabs the drug store sells for diabetic testing are less likely to drip, cheap and work well.  Unless you are playing a  bass, one swab per string works for most people.  If you decide to embark on this adventure in cleaning, before you wipe, protect the fingerboard and top plate of the instrument with a waterproof covering like plastic wrap. Alcohol will quickly soften and dissolve your varnish.  This will make some Luthiers  wince at first when you show it to them  and then slowly and privately smile as they estimate the cost of repairing your self inflicted varnish pox. Eventually, cleaning strings this way won't get out all the deeply embedded sound-killing grime that builds up over time and stronger cleaning measures will be needed. That's when StringCleaningTM can provide a cost effective and easy way to revitalize your strings and save you some money.  

Needless to say, some of those who manufacture strings or profit from their sale are not great fans of our thrifty little enterprise since it saves you money and decreases their substantial profits. Ever try to return some new strings to these folks  because you didn't like them?  Unlike naysayers  in the string-making and selling  business, we stand behind our work 100%. Trying us out is risk free.   Luckily we only need your approval; not theirs.    CODA