IN SEARCH OF THE IDEAL DRUM
Dissatisfaction with the sound of drums in the early 1950s is what started "the search" in the latter part of the decade.
What, specifically, was this search all about?
To find a better material for drum shells, because I had decided that was the key to solving the major problem with the sound of drums.
The drum shell material had to be able to:
respond with minimal effort resonate equally throughout the full spectrum of sonic vibrations project all levels of sound without distortion blend musically with other instruments distribute balanced sound patterns throughout any performance environment either indoors or outdoors not suffer adverse effects from moisture (which readily affects sounds by clogging the porous openings of many materials avoid "killing" sound through absorption, but rather act to enhance the sound.
So what would be capable of meeting these criteria in all situations?
Would it be an existing material that could be greatly modified or something completely new?
CRITERIA FOR DRUM SHELL MATERIAL
The material will: Be a homogeneous, single-ply substance with the least amount of internal/external imperfections or weaknesses - as "pure" a substance as possible. Require no internal/external coatings for any reasons. Contain no fibers or fillers, as they greatly distort the sound properties of any material, for example: wood, fiberglass, etc. Not be affected at all by moisture (wood is the shell material most adversely affected by moisture). Be flexible enough to resonate at approximately the same vibratory rate as that of a stretched drumhead. Not be noticeably affected by the aging process (organic substances such as wood have a rapid rate of decay). Absorb the least amount of sound. Be the least dependent on its surrounding environment for good sound quality, in other words, always sound good no matter what the environment or situation. Have a molecular chain configuration that enhances the transmission of more defined sound vibrations. Carry only a single impact sound with; no secondary impact sound (my use of the word "secondary" does not refer to overtones). Be at least as "smooth as glass." Be solidly cast - not extruded, sprayed, laminated, or pressed, etc. - Have many practical decoration possibilities.
THE RESULTS
Out of hundreds of experimental tests conducted over a twenty-year period, the following is a representation of a few of the materials and processes tried. The process used to produce the material has a tremendous impact on the end result of the material's sonic properties.
1. Wood
....Plywood: Thickness of material varied from 1/8" to 5/8" parallel- and cross-lamination of plies (laminates glued with various glues), hot and cold forming processes used with both soft and hardwoods.
....Solid Wood: Thickness of material varied from 3/8" to 5/8", machined from solid block of wood.
....Barrel Stave: Thickness of material varied from 3/8" to 5/8", wood staves glued to form drum shell
Both soft and hardwoods were tried.
All wood shells were mounted with metal die cast lugs, metal machined lugs, or solid wood lugs attached in a number of unique ways. I interchanged metal counterhoops (pressed or rolled, spun, and die cast) and wood counter hoops with all manner of configurations of lugs: this refers to materials used as well as to methods of attachment. Up to ten coats of varnish were applied to all wood shells on the outer surface only, inner surface only, and to booth the inner and outer surfaces. Testing began with the shell in its "raw state" (unvarnished) and followed with the shell in a varnished state. Testing continued both with and without "sound" rings. The shells were sanded extensively to obtain as smooth of a finish as possible.
2. Metal
* Brass, Copper, Bronze, Aluminum:
Thickness of material varied from approximately 1/64" to 1/2", the thinner materials were either spun and machined or rolled and machined. Some of the metals were also heat-treated.
* Stainless Steel and Carbon Steel:
Thickness of material varied from approximately 1/64" to 1/8", these materials were were either spun and machined or rolled and machined.
Some of these shells were also heat-treated.
All metal shells were tried in both their "raw state" (non-plated) and then with various plating materials. The combinations of the metal shells utilized only die cast or metal-machined lugs and counter hoops.
3. Plastics
* Fiberglass: Thickness of material varied from 1/8" to 3/8"; both continuous glass and chopped glass fillers used in various resin combinations. The three manufacturing processes were: hand lay-up, sprayed, and filament wound. The two types of molds used produced either a smooth outside/rough inside combination or a smooth inside and outside combination.
Fiberglass was the one material that could be relatively easily formed into various shapes. The shaped tried included cones, cylinders and bowls. The same lugs and hoops that were used on the metal shells were also used on the fiberglass configurations.
* Acrylics: Thickness of material varied from 1/8" to 1/2", these were either wrap-formed from both extruded and cast sheets, or made by cutting sections from extruded tubes.
The same counter hoops and lugs (with all their unique attachments) configured with the acrylic combinations.
*Extensive moisture tests from performing outside in the rain to immediately performing indoors under the heat of stage lighting.
*Extreme contraction and expansion tests by leaving drums in a metal van with temperatures reaching 140° F, then bringing them into air conditioned rooms with temperatures around 74° F, and testing under all types of playing process was also leaving the drums full stage lighting with temperatures reaching approximately 86° F, and testing under the same very long playing conditions.
*Many variations of all head bearing edges were tried in combinations with all materials used. Bearing edge experiments brought about some unique surprises.
*Exhaustive methods to eliminate "secondary" sound in nearly a hundred performing situations.
*Many, many combinations of drum heads in different materials, thickness, plies, and levels of tension.
*Drums on stands, drums mounted with drum holders and drums "freely" suspended.
*And tests to determine the effects of sonic properties of fibers and fillers in all the various materials, such as sound absorption of the materials in all manner of combinations and the effects of smoothness on the projection of the sound.
After prolonged testing covering a period of nearly twenty years, one conclusion was most apparent: the one material that stood out head and shoulders above any of the others tested, and that corresponded to all the criteria listed above, was the cast acrylic in combination with Mylar drum heads.
We are currently researching "engineered" materials to produce an even more sonic-resonant material. The "engineered" materials refer to those that have molecular chains which can be structured, as to length and type, to any desired combination that will literally produce any precise sound desired but still sound like a musical instrument should sound.
Zickos Drum Company |
