Sona is a professional tuning method for timpani and enables fast, precise and quiet tuning even in noisy environments. It replaces chromatic tuners, tuning apps and tuning forks. Timpanists use Sona for tuning before concerts, retuning between pieces or setting up tuning indicators and timpani heads.
The resonance tuning principle works fast, exact, quiet and also in noisy environments.
The tuning process is stepless and display errors are excluded.
As soon as the head resonates it vibrates with the same frequency as the excitation frequency.
Tuning is done orchestral-compliant, as like tapping or lightly striking the timpani in pianissimo.
Tuning is possible even in noisy environments, as the tone to be tuned can be focused and all others filtered out.
The currently used ways of tuning timpani are time intensive and often inaccurate. In short, tuning is cumbersome. Especially during the stressful situations, a reliable solution would be welcome.
Details
Typically, timpani are tuned as follows: If the currently tuned tone is not known, the timpano is hit softly and the tone identified by ear or tuner. The timpanist now knows whether the head should be tensioned or relaxed in order to reach the tone to be tuned. Then the timpano-head is retightened by feel and experience. To detect the adjusted tone, the timpano must be strike again. If the tone is still not right, it must be tensioned again. These steps must be repeated until the desired tone is set.
The tuning process is iterative.
Electronic tuning devices or apps do not accurately display the note. Often the pointer jumps back and forth, or during the recognition process one note is displayed initially and then another. The tuner must be watched carefully. To counteract this, it is necessary to strike the head several times or to change the strike position or volume.
The tuning process is time intensive.
The timpano tone consists of sound-characteristic partials, which are almost equally loud and occur simultaneously. Tuners do not manage to keep the partials apart and determine the fundamental. Improperly tensioned heads, may lead to impure fundamentals, which again lead to the display of incorrect notes.
Details
The first diagram shows the Fourier-analysis of an audio recording of a timpani stroke. With the Fourier-analysis it is possible to decompose a signal into his frequency-portions. The harmonic intervals of the timpani tone are the fundamental, the fifth and octave. The difference in amplitude (loudness) of the harmonics is low. That’s the reason why tuning devices have problems to detect the fundamental note and the indicator jumps back and forth between two notes.
Timpani heads as well as the whole timpani are very sensitive instruments. Fluctuations in temperature and humidity as well as poor maintenance, or transportation result to changes in the delicate tensioning system. The consequence are improperly tensioned heads, which may lead to double peaks on the keynote. In the shown example the timpano is tuned to „c sharp“ with 139Hz. However, the tuning app have displayed 145.1Hz, which is near “d” with 146.83Hz.
Resonance is a physical phenomenon and occurs when a dynamic system is excited with its natural frequency and thereby vibrates more strongly. Examples are a tuning fork, the body of a string instrument, a resonance exhaust of a two-stroke engine, but also when a singer bring to shatter a wine glass with his voice or strong winds cause a bridge to collapse.
As you might imagine, the resonance principle can also be used to tune timpani. In this case the loudspeaker excides the timpano-head with the frequency you want to tune and the microphone is used to record. When you start stretching the timpano head from the lowest note, at some point you are going to hear that the tone is getting louder and louder. This is the point when the excitation frequency begins to match the natural frequency of the head. It resonates.
In the following track you can hear a resonating timpano-head. The blue waves in the image display the amplitude response of this recording.
You can hear and see that the resonance amplitude is a multiple higher than the excitation frequency. Once the amplitude reaches its peak (apex) the timpano is tuned. The tone can be recorded by a microphone and then evaluated by electrical devices, or simpler by your aural sense.
There are several ways to integrate the resonance-tuning-method in the timpano. I have designed and build a lot of prototypes and tested them, to directly experience how the modifications affect the instrument.
"Sona" stands for the core components of this tuning method. It is the simplest variant, since simply no integration is necessary. This also fits with the experience that by any additional component, the original sound character of the instrument is changed, thus no conversions are desired.
A small Bluetooth speaker serves as the loudspeaker, which the timpanist holds over the head. The evaluation of the volume, in order to determine the peak of the amplitude, is also done by the musical ear of the timpanist.
It is fun to experience physics directly on the instrument. Also, you will very quickly get a feel for this tuning principle.
Try it out. :)
When I began to take an interest in music in my childhood, I soon wanted to learn a musical instrument myself. I decided to play drums because I was fascinated by the various rhythms. After a while I played in the local brass-band and later in a rock-band. Especially during the many concerts, I noticed how awkward tuning of timpani was. The idea of at the push of a button automatically tuneable timpani originated here. Due to my interest in technology and my school career as a mechanical engineer and product designer, I soon began with the implementation. This led to my final thesis at university. My development opened the way to a manufactory where I developed and assembled percussion instruments for notable orchestras. I couldn't let go of the project and in my spare time I kept designing new devices, all of which revolved around the recording and processing of vibrations and their integration into the timpani. Following Dieter Rams' principle of making the design as unobtrusive as possible, the project did not result in a fully automatic tunable timpano, as initially desired, but, with the involvement of the human senses and condensed to the core components, in Sona.
Behind the scenes
I am glad to refer to contacts I made during the project.
The exchange with specialists of their field was always stimulating, either via forums or in personal conversations.
Since resonance plays a central role in this project, I would also be happy about resonances from outside.
