Colin’s Corner: Wood Slats

Welcome back to Colin’s Corner, where we can all learn secrets and tricks from our studio manager and resident superhero, Colin Campbell. In this post, Colin explains his process for making wood slats, a very common percussion instrument that takes a bit of care in order to sound great. So many of us settle for mediocre woodslats, but with a little time and care, you can have beautiful, pitched wood slats that will last you for years (unless you play Music for Pieces of Wood 10 times a day for a while). Here are Colin’s tips. 

What kind of wood?

All of Third Coast’s wood slats are made from red oak, which is more economical and sustainable than many hardwoods, and widely available.

What size?

See the table below. (The dashes mean that TCP hasn’t made a slat that size…yet!)

I’m in Home Depot. HELP!

When choosing the size of plank to buy, YOU SHOULD KNOW:

Boards in hardware stores are labeled by ‘nominal’ dimensions, which means that the actual measurement of the wood will be slightly smaller than listed.

–The boards that I buy for pitched slats are 1” nominal thickness, and either 4” or 6” nominal width. This actually translates to a ¾” thick board with an actual width of about 3 ½” or 5 ½”.

There are so many planks…

I like to buy my boards in lengths between 3’ and 6.’

Hold each board by its edges and tap on its face. Even at this stage, the wood should have a clear and resonant tone when struck. Be careful not to buy any boards which sound “dead,” as this is most likely a result of internal defects in the wood’s structure.

Try to buy boards which are as flat and straight as possible. Setting a board flat on the floor will give you an idea if it is bowed, twisted/ warped, and/ or cupped.

How do I cut it, and what do I cut it with?

All of the saw cuts will be “cross-cuts,” meaning we will cut perpendicular to the long grain of the wood.

There are many techniques for cross-cutting wood. The one use will depend on your access to the particular tools. My personal choice is a compound miter saw/chop saw. I can make cuts precise, clean, and quick. BUT around the studio, I don’t have a compound miter saw, so I usually use a jigsaw.

We are only cutting the board to length — we are not making any additional cuts to tune the note harmonically, as would be the case with a wooden marimba or xylophone bar. This means that a particular slat might have a fundamental pitch, as well as an unwanted harmonic (say, a Major 2nd, for example) that is nearly as audible as the fundamental itself.

Make your first cut a couple inches longer than the listed dimension. Your first cut should give you a slightly lower pitch than the intended target. Now, make a series of smaller and smaller cuts to “sneak up” to the final pitch.

Listen carefully as you go, and compare your note with a pitched instrument like a marimba or piano. Strike different areas of the board to find a “sweet spot” where the fundamental pitch speaks most clearly. Once you have the board cut to length, circle the “sweet spot” with a marker or pencil.

Tell me more!

I’m still playing with the widths, but generally I like to use the 6” wide boards for everything Middle C and below, and switch over to the 4” wide boards above Middle C.

But remember: the measurements given are only a guide. There will be natural variability in the wood from board to board.

When cutting multiple pitches, always start with the lowest note/ longest board. That way, when (not “if”) you cut off too much and overshoot the pitch, you’ll still be able to use the board to make a higher note.

Finally, as I mentioned, the measurements are a guide. Remember to leave extra room and sneak up to the correct pitch, rather than cutting the board too short on your first cut.

Good luck!

Pitch Octave 3 length Octave 4 length
C 23 1/16″
C# 23 1/16″
D 22 1/2″
D# 21 9/16″
E 19 1/16″ (4″, W)
F 20 3/4
F# 28 1/4″ 21 3/8, 19 3/8 (4″, W)
G 26 1/2″ 18 11/16 (4″, W)
G# 26 7/8″ 18 7/16
A 24 11/16″ 17 7/8″ (4″, W)
A# 24 13/16″ 18 5/16″
B 23 1/2″ 16 13/16″ ; 16 5/8″

 

Pitch Octave 5 length Octave 6 length Octave 7 length
C 16″ ; 15 1/2″ 11 1/8″ 8 3/8″
C# 15 1/2″ ; 16 1/8″ 11 1/2″ ; 12″ ; 10 7/8″ ; 12″ ; 7 3/4″
D 16 1/4″ ; 16″; 14 3/4″ ; 15 1/2″ 11 3/4″ ; 11″
D# 15 7/16″ 11 1/2″
E 15″ ; 13 7/8″ ; 15″ 10 13/16″
F 14 5/8″ ; 14 3/4″ 9 3/4″ ; 10 11/16
F# 13 1/2″ 9 1/2″
G 13 9/16″ 9″
G# 13 3/8″ 8 1/2″
A 13 3/8″ ; 13 11/16″ 8 3/8″
A# 13 3/8″ ; 13 11/16″ 8 1/14″
B 12 3/4″ 7 13/16″