Tempering a Head Which Has Already Been Mounted on a Drum
So, how do you make your timpani sound like musical instruments if they don’t vibrate with a harmonic series? How do you get timpani to blend with other instruments? How do you achieve this “correction of the overtones into a close approximation of a harmonic series” as Lord Rayleigh prescribes while clearing heads on timpani or, as I like to refer to it, tempering the timpani? Are we able to detect the missing fundamental?
Start by eliminating as many variables as possible. For good timpani pitch the following criteria must be met.
1. The timpano bowl should be free of large dents and must be in-round.
2. The lip of the bowl (the bearing edge) must be in-round, smooth, level and free of any nicks, dents and imperfections and create an air tight seal between the bowl and head.
3. The counterhoop must be flush/level and in-round.
4. The flesh-hoop must be free to move inside of the counterhoop.
5. The head must be true, free of dirt and defects and be centered on the drum.
6. The mechanics of the timpano must be functioning so that a uniform or equal tension can be maintained at all lug points throughout the range of the drum.
7. For drums with a balanced action mechanism, the proper *MSR for the size of the drum must set. (this varies greatly from manufacturer to manufacturer)
Assuming all the above exist you can proceed to tempering or clearing the drum.
* MSR refers to the to the Manufacturer’s Suggested Range for size of the drum when the pedal is in the heel down/toe down positions. If the MSR is not correctly set, the balanced action mechanism may not function properly and may impede the range for the timpano. Please check the manual which came with your timpani for the suggested range for each drum. Early American models of timpani featuring the balanced action mechanism tend to have less range than later European models.
The concept of the BAM ( balanced action mechanism) is relatively simple; a pedal is placed mechanically in between a spring and the timpani head – when the tension of the spring is matched to the tension of the head, the pedal is balanced and the pitch of the drum will stay where you set it.
Nomenclature of a Yamaha Timpano
courtesy of the Yamaha Corporation