TUNING:
Also we can tune Squeezeboxes which we do by tuning the reeds inside the Box. However this is not as simple as it is to tune a guitar. Unfortunately you can't repeat this as often as with a stringed instrument, because for tuning reeds we have to remove metal from the reeds tongues! Also it is a much more time-consuming process and should not be rushed! The final tuning of the tongues is done in the instrument. Before installation of the reeds they are tuned somewhat higher in tone at the tuning table. However the pitch of the sound of each reed tongue is also influenced by the reedblock, the valves and by the construction the squeezebox. After the reeds are secured to the reedblock they should be re-tuned on the reedblock. The operation of the valves also influences the pitch of the reeds and has to be controlled too. It is absolutely essential that tuning is done in several steps. Also after some playing the inmstrument the pitch can change. The room temperature should be held constant. The squeezebox must have adapted its temperature in the room for a day. Longer manipulation on the Instrument also leads to temperature variations at the instrument. Therefore the final fine tuning of the reeds should be repeated over several days.
Reed tongues can be tuned not only higher, they can be tuned lower too. If some material is removed from the tip of the tongue, the note gets higher in pitch, if material is removed from near the root of the tongue, the note gets lower. There is also another method to get the pitch lower, more about this later.
For tuning , one needs several tools: files, scratchers, Lösblättchen, hooks, etc. (Picture of files as the are available at Pigini ), (address of Pigini). Moreover it is highly recomended to get oneself an electronic tuning device. That does not have to be an expensive pointer instrument, low-priced computer software does also work. (tune!it Download) Tuneit has the advantage, that different tuning scales are supported. However for precise tuning one should not rely only on the tuner. The Differntal tones (beats) should be used to check the tuning. In the tuning of organ, the beats of the sounds are checked too. If one has the skill, the tuning by our human ear is far better and much quicker. Experienced piano tuners have confirmed this to me. The tuning is performed in several stages, the reeds (picture of a reed) are pre-tuned at the tuning table (Picture of the Tuning-Table) before they get put on the reed block. After the first tuning, the reeds will be mounted on the reedblock and tuned again.
With the reedblock mounted inside the instrument, first the reeds with the reed tongues inside the reedblock, which are sounding on pull action, are tuned (picture). To get to the internal reed tongues, which are responsible for the pull tones, we need a "hook" (picture my prepared hooks) to lift the inside tongue through the slot in the reedplate high enough to be able to file it (pictures of using a hook, picture tongue lifting, picture tongue raised ,picture tongue raised large). At the same time the "set" of the reed tongue may be changed and the tongue must be bent to restore the correct gap. On each case the tongue gap (that is the height of the reed tip above the reed plate), can be changed through manipulation and the reed tongue should be bent back again afterwards, if it is needed. This bending back can also change the tuning of the reed again. One should avoid taking the reeds off the reedblock, because, especialy on high notes, a slight variation of the position of the reed on the reedblock leads to a change of pitch.
For the tuning itself, one begins with the „Gleichtone“ in second row. Start with the pull tongues, because to reach them - as described above – is the most difficult. The low reeds tongues, are large and strong, the quantity of material to remove with the file for a given interval is quite large. The high reeds are much smaller and correspondingly less material is remove for the same interval change. Once again with the high reeds: take care! Often it is sufficed to make a small scratch with the file, and the pitch of the tone is changed a lot specally on high tones!
A table which shows how the notes are related is shown on my web page: The harmonic web
For the note layout of the diatonic squeezebox please see:The harmonic construction of the diatonic squeezebox, the bassside of the diatonic squeezebox
To support the reed while filing, one pushes a very flat piece of sheet metal between reed-tongue and reed-plate. This is called the „Lösblättchen“ (or anchetta in Italian). It is made out of an old bass reed tongue which is tapered to a razor-sharp end. This works very well. It should be obvious, but nevertheless I will make this very clear: when filing reeds one works only with the flat side of the file on the top surface of the reed tongue. As one files at the tip of the tongue, the swinging mass becomes less and as a result the note gets higher. As one files somewhat above the root of the reed tongue, the tongue there will become thinner, the elasticity gets weaker, and the note gets lower. I have already indicated how one checks the pitch after each little filing, with the electronic tuner and with the ear using beats.
Special caution must be taken on filing at the root of the reed tongue: if one files a notch, the reed can easily break there, never file with the edge of the file! I prefer, not to file across the reed but to work with the scratcher. While using the scratcher I push material toward rivets. Using this method the reeds tongue is made slightly less stiff but without the danger of damaging the edges of the slot in the reed plate. This method also permits more exact adjustment of the reeds than with the file and also works with pull tongues without dismounting of the reeds from the reed block. That is especially useful if one only needs to lower the pitch of pull notes. But caution: Do not scrape away to much, otherwise one must file the tip again and the tip of the reed should not get to thin too! On high notes the tip is very thin and it may be needed to file with the file not toward rivet, file by pulling the file away from the rivet prevents bending of the toungue tip. For high notes it is very important to keep equal thikness in crosssection of the toung otherwise the tongue may touch the edges when vibrating (propeller). If it is possible one can file one time with the right hand and then with the left hand so the surface of th tip stays smooth and equally thick.
If one wants to tune a reed tongue over larger intervals - a halftone or even a full tone deeper, or on Helicon reeds it me be necessary to tune down one octave, it is unlikely sufficient material could be removed, and filing is not only dangerous, but also rather time-consuming. It is easy to remove too much material between two inspections and the reeed is no longer be retuned. I make use of one other method for that, but only if it is realy needed: applying material at the tip of the tongue with a soldering iron, in the form of soft solder or adding a brass weight. It would be better to spot weld the brass part to the tongue. This is being done in factories today. If the tongue gets too weak the sound quality will suffer. Mass and spring power must stand in a well-balanced relation to one another. The sound of the tongue should not be worse afterwards - only the note should be deeper. To obtain the correct note the reed must tuned, by filing off of surplus solder or brass. One must also take care that the solder remains only on the top surface of the reed.
After tuning the reeds you must always adjust the Tongue gap! The tongue gap is the height of the tip of the tongue above the reedplate. This is certain to be incorrect if one scratches or files the reeds. A rule of thumb is that the tongue gap should be approximately as large as the thickness of the reed tongue. Because lower reeds tongues are thicker, they need larger tongue gaps than higher reeds. One adjusts the distance by bending of the tongue carefully in the corresponding direction, with the scratcher. If one would like to enlarge the tongue gap, one can also press the „Lösblättchen“ (therefore the name) carefully under the tongue.
One can also adjust the tongue gap, more accurately to make the reed sound correctly: smaller tongue gap causes easier response of the tongue to a slight bellows pressure, but this can also lead to the note choking; if one blows the reed suddenly with high pressure - then it simply does not sound at all. Large tongue gaps prevent this danger and the tongue always speaks with high bellows pressure. (However this also leads to much air loss in the playing of the squeezebox).
To tune the very deep notes on the bass side, one uses a piece of paper to block the higher of the two reeds in the removable helicon reed assembly. Block one of the two bass reeds and, put the accordion back together with adhesive tape on each side. Play the note and determine if the selected reed is out of tune with the respective higher reed on the treble side by listening for the beat, a tuner should be able to tell how much it is out of tune (flat or sharp), use files to tune the reed in question. You can use a hook to pull the reed out, but on very low reeds you can easily take the reeds out and adjust the tuning. You can tune it on the tuning-table and set it back in, play as before and check for beat. If you make notes of several reeds each time you can do several tones at once. But be careful sometimes we can’t remember the exact offset. In the beginning it is better to start one by one. There is an other problem with the very deep helicon reeds when tuning. Sometimes the two reed tongues do not have the same pitch change on different air pressure, if this is the case the tongues have to be changed. The final tuning of the helicon reeds must be dune with both reeds. If both reeds are active a little pitch change occurs, usually they get a little bit sharp, when they sound together in unison one octave apart. So it takes a lot of practice to do a good job.
The tuning of harmonicas is similar. On the Internet, one finds many article on this subject in English language. have a look at my link page.
Short video showing how a reed is riveted (Video). Short video showing how a reed is removed (Video).
Harmonicas are tuned in the same way too. Text: The tuning of a harmonica
I
would like to mention here also a Report
from Klingenthal
of Hans Hoyer (HARMONICA PLAYEREWS nr. 10 - 11/01)
Last
edited by: Theo Gibb
