We are not always inclined to consider all the factors that influence the sound of the drums. When we are about to buy one, we evaluate the type of wood, the measurements, but few notice the thickness of the drums and how the edges are made.
The factors are many more, the drummer, for example, is one of the fundamental, if not the most important, but in the end, the battery is formed (almost always) by layers overlapped and glued together and their number and thickness assume a very important role.
We have already said that they are formed by thin layers of wood glued together and that the type of wood used and the material used for glueing can vary depending on the quality and therefore the cost of the battery.
Important factors, however, are the choice of the hides (wing = above and resonant = below) and the cutting of the edges.
Generally, the thinner the stem, the more it resonates, the more open it is and the richer it is in harmonics, to the detriment of volume. This is because a thin drum (max 7 mm) tends to vibrate more if beaten; in fact, the energy given by the blow is used for the most part in the vibration of the drum drum, so the remaining energy that should give volume to the blow is low: the sound that will result will be more resonant and warm but with less volume.
Drums with more layers instead have a more powerful sound, with more volume and a more centred note, due to the rigidity of the drum that causes a low dispersion of energy. In this case, however, some drummers complain about the lack of “body”, that is, of the frequency range given by the vibrations of the wood and that makes these drums sound colder.
“The thin drum resonates more,has more harmonics but has less volume”
Generally, we find 6 layers in the toms and 8 in the eardrums, but all this is subject to variation depending on the manufacturers and models.
Speaking of wood, we have seen how the use of different types of wood influences sound performance. Because of the thickness affects the volume, the “colour” is given by the wood used and how the veins that compose it are positioned.
“The volume is a consequence of the thickness,the ‘colour’ is given mostly by the type of wood”.
THE VEINS ARE JUST AESTHETIC?
Not! On vertical veins, the fundamental of each drum drops in tone because they are responsible for the propagation from the sash (high) to the resonant (low). Lately, some companies like DW are experimenting with drums with layers with different directions of overlapping veins to obtain special sound characteristics. So we have the already mentioned vertical layers, the horizontal ones and the crossed ones.
One of the first to focus on edge processing was Gretsch. They introduced Rounded Edges, the completely rounded edges of drums. This process allowed the transmission of energy to the drum through the entire thickness of the drum, through the edge-leather contact that took place on a larger surface than the classic cut of wood used until now, with the exaltation of the central note without harmonics and with the maximum depth. Today almost all the manufacturing companies use this device and fighting with copyright, considerable experiments have been made and the processes have now become an infinity.
Without going into too much detail and postponing the more in-depth discussions to the many forums on the net, we can cite the three main types of 45° edge workings: 45° Bearing, 45° Round Bearing and Full Round Bearing.
The difference is in the rounding of the barrel and therefore in the surface of skin contact with the wood. These different processes modify the sound and help to obtain more volume in the 45° Bearing (used mainly for snare drums), more attack in the 45° Round Bearing (in toms) and more depth in the Full Round Bearing (timpani and speakers).