The Ekdahl FAR - Tuning

The importance of tuning

Getting the tuning right is fundamental to get the string to sound the way you want at the various overtones. Unlike a regular instrument, the Ekdahl FAR will not just sound "out of tune" if not tuned correctly, but won't be able to calculate the right speed for the harmonics. Thus the instrument will sound dull, create a "beating" sound or not resonate at all.

Since the instrument relies on the tuning information stored in it, this means that if the tuning of the actual string deviate by as little as a tenth of a Hertz the bowing motor speed given will not correspond to the resonant points on the string.  

A couple of things should be realized before we get started; this being an acoustic instrument we're talking about physical strings fastened to physical objects and all of these things will shift due to things like temperature, humidity etc. To make matters worse, a string heats up a lot during initial playing and will thus expand. My recommendation when preparing to use the instrument is to turn it on ~10 minutes before "serious" use, play the instrument as intended for a while and tune the instrument. After 10 minutes or so, adjust the tuning again as required - it should now be good for a while.

The first order of business is getting the tuning within +/- 50 cents of the desired note by adjusting the tuning peg using a piano tuning hammer. The tuning could be monitored by ear, using an audio reference or with the help of the automatic tuner in the configuration software. Make sure to NOT try and force the tuning peg down too low, around 6mm / 1/4" of the threads on the tuning peg should be visible at the lowest point. Trying to turn the peg further into the tuning block than this could end up cracking the block, rendering the instrument unplayable.

Tuning using the control box

Once the string has gotten close enough we need to use the bowing wheel to get it perfect.

Start by turning the harm. shift modulation knob to zero, putting the harmonic shift knob in the middle position and the harmonic knob at the zero position - this will set the motor to emphasize the fundamental. Make sure all the other knobs are turned all the way to zero and flip the gate switch to on - this will start the motor. Slowly turn up the pressure baseline knob until the bowing wheel rubs against the string with a steady speed, since the string isn't yet properly tuned it may not resonate.

Be careful to not add too much pressure, the bowing speed being uneven is often a good indicator that the motor isn't able to keep up and may be overloaded due to the bowing wheel being pressed too hard into the string.  

Use the fine tuner on the Ekdahl FAR (located right below the tuning peg) to get the instrument to start resonating, depending on the string it may be difficult to turn the knob by hand in which case you can use a hex key. It should be abundantly clear when the tuning is right as the instrument will go from making a fairly quite "scraping" sound to much louder full resonance.

The string will resonate at the fundamental even if the string tuning is off by a few cents so the next step is to make sure that the 12th harmonic number (one octave up) is also resonating by turning the harmonic knob up and verifying the string tuning. Watch out for any beating, adjust if necessary. The final tuning is usually done by checking that the 7th harmonic number also sounds correct.

One can keep going and check the more "difficult" harmonic numbers in order to tune the string even better, but whether these overtones are present or not depends on your string choice, string dampening, bowing wheel etc. There is a definite possibility of trying to approach certain "impossible" overtones and thus detuning the entire instrument to the point of having to start over. As a rule of thumb, the closer the harmonic number is to the fundamental or its octaves, the more difficult it is to make that overtone  resonate - the 1st, 2nd, and 11th harmonic numbers are rarely present or they are too close to the fundamental meaning that the fundamental will "swell in" and take over.

Tuning using MIDI

When using MIDI to tune and play the instrument, if the control box is connected its parameters may override any MIDI messages sent. Hence before continuing, all controls should be zeroed except the harmonic shift knob which should be set to its middle position.

First thing that needs to be done is to locate the key which corresponds to the fundamental tuning of the string and add enough pressure that the bowing wheel is firmly rubbing against the string. Refer to the "MIDI Setup" if you have difficulties with this. The next steps are the same as in the previous paragraph.  

Tuning on the fly

Sometimes retuning can be quite cumbersome, in for example a live setting you may not be able to just stop everything you're doing to retune the string. One can temporarily "correct" small deviations by adding a small harmonic shift by for instance using the control box or a mapped MIDI controller.

Please realize that this means that the string is still out of tune and you actually just made the electronics do it wrong too to compensate so it may sound funny with other instruments and some harmonic numbers ratios may get whacky - sometimes funny and whacky is good tho.