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Drum Shells Explained
To Find a Perfect Sound
Drum shells are more complex than you may think. They can be made of wood, metal, acrylic plastic, carbon fiber, and other materials. However, wood has been the main choice by builders and drummers alike for many years.
WHY? Likely due to the nice tone, the natural beauty, and the crafting experience gained throughout history. Since wood is the most common material used, why don't we take a peek at how a tree becomes your instrument of choice...
Drum Shell Construction
In order to demonstrate the ways drums shells can be contructed, custom drum builder Oregon Drum, has allowed DrumJunction.com to use some of their great pictures and contribute information about each type. So let's get started...
You've seen plywood before right? Thin pieces of wood called "laminates" or "veneers" (which are shaved from a solid piece) are stacked with alternating grain patterns to increase strength of the finished product.
Thin plies of various woods are held together with fillers and glue. Heat and compression molding techniques are used to produce these plywood cylinders.
Often, only the inner and outer-most plies of these shells are made of a quality hardwood. This can result in portions of the bearing edge consisting of glue, filler or a gap in the wood ply altogether. (Gaps of air don't resonate very well.) Even with plies or an outer veneer of an exotic wood, the shell still consists of thousands of square inches of glue.
Stave drum shells are made in a method similar to constructing a barrel, where sections of wood are joined by either spline or butting methods which is held by glue.
This technique provides phenomenal strength and rigidity while maintaining the tone and response of a solid wood shell.
One of the most valuable qualities of a stave drum shell comes from the vertical grain bearding edges which conduct vibration and resonance and sound through the shell far better than any other shell configuration. This method greatly improves the quality of wood in contact with the drum head as hundreds of square inches of glue are eliminated from the process.
Another wonderful characteristic of a solid wood stave shell is the extremely low "glue to wood" ratio. We all know that glue is a dead component, it makes no sound at all. Solid wood allows us to lower the amount of glue used to build a drum shell and raise the wood content resulting in a truer, richer, and more melodic sounding drum.
Sean Murphy of SMD Custom Drums has provided a great mathematical comparison of the total square inches of glue joint area between plywood and stave drum shells.
(note: this is a comparison of two 6" X 14" snare drum shells of the same mass. the plywood shell has 10 veneer plys)
| Ply shell: |
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Stave shell: |
| 3.14(pi) x 14" = 43.69" x 6" =263.76 sq. inches x 9 glued plies = 2,373.84 sq. in. |
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0.25" x 6" = 1.5 square inches x 16 staves = 24 square inches of glued area |
Conclusion:
Stave shells use 0.01% of the glue that normal ply shells require. Glue has no tone factor whatsoever in fact it is a tone inhibitor. Wood is good, glue is dead.
The shell walls on these drums are built from stacked rings of wood segments. This type of construction creates a sturdy shell once it is glued together and turned into a cylinder on a lathe.
This method improves the quality of contact with the drum head as there are few glue joints touching it. That said, since each shell is built from a number of these segmented rings (essentially stacked staves), there is still a considerable amount of glue content.
Some of the finest acoustic snare drums offered today are built in a ‘steam bent’ or 'single-ply' manner. Some manufacturers incorrectly refer to them as 'solid'.
The shell walls on these drums are built from a single plank of lumber, bent into a circle over time with steam and bending jigs.
This type of construction creates a sturdy shell once it is glued together at a single scarf joint and turned into a cylinder on a lathe. This shell type utilizes reinforcement rings at each bearing edge, necessary to stabilize the shell (as shown in the picture). Because of this, they aren't truly a single-ply shell at all.
This method greatly improves the quality of contact with the drum head as there is only one glue joint touching it. Oregon Drum has found that this shell type to be one of the most resonant, truly musical construction methods available
Of the drum shell types discussed here, the "solid" shell shown to the left is the only one that is of ONE piece of wood with no support or glue.
Many in the drum industry use the generic term 'solid' to describe all manner of segmented, stave and steam-bent single ply drums.
Our friends at Oregon Drum are among a handful of companies around the world offering a 'true solid' shell. In the case of their Myrtlewood Series, solid is truly a seamless shell lathed from a round of kiln dried, relaxed wood. In other words, a hollowed out tree trunk. No other construction method allows the wood to freely offer it's contribution to the sound of your drum the way a true solid does.
SIDE NOTE: Danny Brown's Ultimate Guide for Choosing Drums and Cymbals. DrumJunction provides not only more detail about drum shell construction, but he also talks about entire drum kits, cymbals, and everyting you need to know before laying down your hard earned money. Check it out HERE!
Not All Wood is the Same
OK, time to talk about the wood types. As you know, there are many types of trees, each producing a different kind of wood. Some is suitable for shell construction, others aren't. So what make it suitable? Here a several key reasons:
- The tree chosen for a wood source must be in great supply, which makes it affordable.
- The wood must be workable. This means it can be shaved for laminates and then molded to form the round shape of a drum.
- It should be attractive. This applies mostly to higher quality drums which will have a clear coated finish. Cheaper drums are usually wrapped.
- Woods that will have a clear coat finish should stain well, showing off the beauty of the grain pattern.
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Woods used in cheap drum sets (such as eucalyptus, bass wood, & tulipwood) tend to be in great supply and are very workable, but don't finish well. This is why they are wrapped with some type of solid or patterned plastic.
A trick some companies use it to add an outer layer of higher quality wood such a maple or birch for staining. Be sure that the drums aren't sold as "all" maple or birch.
Popular woods used in semi-professional to professional drum shells include maple, birch, and mahogany. Each wood type gives the drum a different sound due to the "character" of the wood. Here's what I mean by character...
Hard vs. Soft
- Softer woods produce lower tones with less projection
- Harder woods produce higher tones with more projection
There are always exceptions to the rule, but these properties usually hold true. Now we have to ask which woods are hard or soft? Let's look:
The Big 3
Starting with mahogany, it's the softest of the three. Mahogany's sofness gives it the lowest tone of the group. You can expect good bottom end punch with this wood.
Keep in mind that the mahogany discussed here is of high quality (i.e. African Mahogany). Many cheap drum sets are made with the cheaper mahogany that is commonly found on hollow doors. The price is less but the tone suffers.
Maple falls in the middle when it comes to both hardness and tone. The pitch is higher than mahogany's, yet it is considered "warm" when compared to birch.
Maple is very popular among many drum makers and drummers alike. Keller Drum Shells has been key to the mainstream popularity of maples shells. The great tonal range, natural beauty, and large supply should keep it on the "most popular" list for years to come.
The final wood to consider is Birch. Since it is the hardest of the group, birch has the brightest sound. It is also very attractive with a nice staining wood grain. The volume you can achieve with birch makes it a pick for drummers in live settings (who like it LOUD!)
Shell Size and Thickness
We all know that small drums have a high pitch and larger drums have a low pitch. Why is that?
1. Shell diameter (how big around) affects pitch more than any other factor. Based on that, a 16" tom will sound much lower than a 10" tom no matter how deep it is.
2. Depth plays a role in the tone (how high or low) but has a greater role in sound projection. Your personal taste, type of music you play, and especially the setting you play in will dictate what shell depth may work best for you.
Thick or Thin?
The thinner the shell, the more it will vibrate and give a rich wood tone. The volume will be less than thicker plies though.
The thicker the shell, the less if will vibrate, but the louder the drum will be, giving preference to the attack of the head rather than the tone of the shell. This is why thicker shell are used for snares and bass drums!
In closing, here are several rules of thumb to keep in mind:
- A broad range of drum shell diameters will speak more clearly to your audience (i.e. 8", 10", 12", 14", 16").
- If you're looking for good tone, go with a more shallow shell. They vibrate more freely allowing the wood sound to come out.
- Go with a deeper drum shell if you're after projection and volume.
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