How To Make A Coyote Howler: DIY Predator Call Guide

Crafting a highly effective coyote howler requires turning a dense hardwood or acrylic mouthpiece, precision-cutting a curved tone board, and attaching a calibrated Mylar reed to a resonant horn bell. By controlling the air channel dimensions to a standard 3/16-inch width and pairing it with a 10-mil to 14-mil Mylar reed, you can produce the deep, authentic vocalizations of an alpha male or the high-pitched yips of a juvenile. This technical guide outlines the exact measurements, machining steps, and tuning adjustments needed to build a professional-grade open-reed predator call.

Material Selection and Precision Machining Preparation

Building a custom coyote howler is an exercise in acoustics and fine woodworking. Unlike standard distress calls, a howler must project deep, resonant tones over long distances while remaining sensitive enough to produce subtle yips, whines, and barks. The key to achieving this dynamic range lies in selecting ultra-dense, non-porous materials that reflect sound waves cleanly rather than absorbing them.

Materials and Equipment Checklist

• Mouthpiece/Tone Board Blank: Acrylic, Delrin, or dense exotic hardwoods such as Cocobolo, African Blackwood, or Osage Orange (Hedge). Dimensions: 1" x 1" x 3.5".
• Resonance Bell: A natural steer, cow, or buffalo horn (5 to 8 inches in length), or a turned hardwood bell.
• Reed Material: Matte or clear polyester film (Mylar) sheets in thicknesses of 0.010 inches (10-mil) and 0.014 inches (14-mil).
• Wedge Material: Natural cork, rubberized cork, or a silicone/nitrile O-ring (size depends on tenon design).
• Machining Tools: Wood lathe with a chuck, standard woodturning gouges, drill press, 5/8-inch Forstner bit, 1/4-inch and 3/16-inch aircraft-length drill bits.
• Precision Shaping Gear: Public tone board jig (metal callmaker's jig), band saw or fine-tooth hand saw, belt sander, and assorted wet/dry sandpaper (220 to 1500 grit).
• Adhesives and Finishes: Cyanoacrylate (CA) glue, waterproof wood finish (tung oil or polyurethane), and epoxy.
• Measuring Instruments: Digital calipers measuring to 0.001 inches.

Budget and Time Benchmarks

• Estimated Cost: $25 to $60 for raw materials, assuming access to standard shop tools.
• Project Duration: 2 to 4 hours of active machining, shaping, and tuning, excluding glue curing times.

Step-by-Step Fabrication of an Open-Reed Coyote Howler

The following workflow details how to create a two-piece open-reed howler consisting of an integrated mouthpiece/tone board insert and a natural horn bell.

Step 1: Boring and Turning the Mouthpiece Blank

Mount your 1" x 1" x 3.5" hardwood or acrylic blank securely in a lathe chuck. Face the end of the blank flat using a parting tool or scrapers.

1. Mark the center of the blank and use a lathe-mounted drill chuck to bore a 1/4-inch pilot hole straight through the center axis of the block.
2. Switch to a 5/8-inch Forstner bit and drill a hole exactly 1 inch deep into one end. This larger opening will serve as the air-expansion chamber and the seat for inserting the tone board into the jig later.
3. Turn the exterior of the blank down to a clean cylinder with a diameter of approximately 0.875 inches.
4. Cut a 1/2-inch long tenon on one end of the cylinder, sizing it to match the inner diameter of your horn bell's intake opening (typically 5/8 inches). Cut two small grooves into this tenon to hold rubber O-rings, which will create an airtight friction seal when joined to the horn.

Warning: Wear a high-quality respirator when turning exotic hardwoods like Cocobolo. The fine dust contains natural sensitizing agents that can cause severe respiratory irritation and allergic reactions.

Step 2: Machining and Profiling the Tone Board

The tone board (or sound board) is the most critical acoustic component of the call. Its slope, known as the "tone channel curve," dictates how the reed oscillates when air passes over it.

1. Insert your turned mouthpiece cylinder into a steel callmaker's jig. The jig holds the blank at a precise angle and features a hardened steel face that represents the ideal slope profile.
2. Use a band saw to cut away the excess material on the top half of the blank, following the angle of the jig but leaving about 1/16 of an inch of extra wood.
3. Use a belt sander or a hand file to carefully grind the wood down until it is perfectly flush with the steel face of the jig.
4. Once flush, use a 3/16-inch drill bit to cut a slot (the tone channel) down the center of the sloped face. This slot must connect directly to the internal 1/4-inch bore you drilled in Step 1. The slot should stop approximately 3/4 inches before the back shelf of the tone board.
5. Hand-sand the sloped face with 320-grit up to 600-grit sandpaper wrapped around a hard, flat sanding block. The face must be absolutely flat side-to-side with a gentle, progressive downward curve toward the tip.

Pro-Tip: Any dips, waves, or lateral twists on the face of the tone board will prevent the reed from sealing properly, resulting in a call that squeals or refuses to break into low-register notes.

Step 3: Fabricating and Tuning the Mylar Reed

The reed translates your breath into acoustic vibrations. A wider reed creates deeper tones but requires more lung capacity, while a tapered reed produces cleaner, faster pitch transitions.

1. Using a utility knife and a steel ruler, cut a strip of 0.010-inch (for pup howls) or 0.014-inch (for adult male howls) Mylar. The strip should be 0.485 inches wide and approximately 1.25 inches long.
2. Taper the sides of the reed slightly, narrowing the tip to about 0.350 inches wide. Trim the two front corners at a sharp 45-degree angle to prevent them from catching or binding on the tone board edges.
3. Position the reed on the flat deck of the tone board. The reed must cover the tone channel slot completely. Align the tip so it extends exactly 1/64 of an inch past the tip of the tone board.
4. Secure the base of the reed using a wedge of natural cork or rubber. Slide the wedge into the slot at the rear of the tone board deck, compressing the reed tightly against the wood.

Step 4: Preparing the Horn Resonance Chamber

The horn bell acts as a megaphone, enriching the raw reed vibrations with natural harmonics and deep bass resonance.

1. Select a natural steer horn and cut off the narrow, solid tip using a band saw until you expose an open chamber with an internal diameter of roughly 1/2 to 5/8 inches.
2. Use a 5/8-inch drill bit to bore a clean, straight receiver socket 1 inch deep into this cut end.
3. Sand the interior of the horn with coarse sandpaper attached to a flexible dowel to remove any loose organic material or debris.
4. Polish the exterior of the horn on a buffing wheel using brown tripoli compound followed by white dialux compound to bring out a high, glassy shine.

Step 5: Final Assembly and Acoustic Calibration

1. Fit two rubber O-rings into the grooves on the mouthpiece tenon. Apply a light coat of silicone grease or mineral oil to the O-rings.
2. Press the mouthpiece tenon firmly into the bored receiver socket of the horn bell. The joint must be completely airtight.
3. Blow air through the call. To tune the call, loosen the cork wedge slightly. Slide the reed forward (increasing the vibrating length) to lower the pitch and create a deeper, raspier howl. Slide the reed backward (shortening the vibrating length) to raise the pitch for clean, high-frequency yips and barks.
4. Once tuned, seal all wooden parts with three coats of thin CA glue or a marine-grade spar varnish to prevent moisture absorption during field use.

Acoustic Engineering Parameters and Material Performance

To customize the acoustic profile of your coyote howler, use the design specifications outlined in this technical reference table:

Real-World Tuning Failures and Remedial Actions

• The Reed Locks Up (Stops Vibrating Entirely Under Moderate Pressure)

  
  
  
  • Root Cause: The reed is too thin for the tone channel width, or there is water tension (saliva) locking the flat Mylar reed to a perfectly flat, non-porous tone board face.
  • Actionable Fix: Lightly sand the face of the tone board with 400-grit sandpaper in a cross-hatch pattern to break surface tension. Alternatively, switch to a thicker 0.012-inch or 0.014-inch Mylar reed, or file a tiny, shallow micro-groove down the length of the sound board face to allow moisture to drain.

• The Call Produces a Flat, Airy Sound with No Vocal Depth

  
  
  
  • Root Cause: There is an air leak at the joint between the mouthpiece tenon and the horn bell, or the cork wedge is loose, allowing air to bypass the tone channel.
  • Actionable Fix: Wrap the tenon with a layer of Teflon tape to ensure a 100% airtight compression fit inside the horn. Replace the cork wedge with a freshly cut, oversized rubberized cork wedge that forces the reed completely flat against the base deck.

• The Call Squeals and Cannot Produce Low-Register Howls

  
  
  
  • Root Cause: The reed is extending too far past the tip of the tone board, causing the unsupported tip of the Mylar to vibrate out of control at an ultra-high frequency.
  • Actionable Fix: Loosen the wedge and slide the reed back until the tip is perfectly flush with, or up to 1/64 of an inch behind, the front edge of the tone board.

• The Sound is Muffled, Raspy, and Lacks Projection

  
  
  
  • Root Cause: The interior of the horn bell is too rough, or the sound channel is constricted by wood fibers or burrs left behind after drilling.
  • Actionable Fix: Run a 1/4-inch reamer or round file through the internal bore of the mouthpiece to clear out any wood burrs. Smooth the inside of the horn bell using a flexible sanding flap wheel mounted on a rotary tool.

Frequently Asked Questions

What is the best material for a coyote howler reed?

The industry standard material for predator call reeds is Mylar (polyester film). It is highly resistant to moisture, retains its shape across extreme temperature ranges, and has the ideal elastic modulus to vibrate rapidly without stretching or fatiguing over time.

Why is an open-reed howler preferred over a closed-reed design?

Open-reed howlers are highly versatile because the caller’s teeth or lips place direct pressure on the exposed reed during operation. This allows you to alter the pitch instantly, moving smoothly from deep, mournful howls to high-pitched yips, barks, and distress cries on a single breath.

How do I control the pitch of an open-reed howler?

To change the pitch while blowing, slide your teeth or lips along the exposed reed. Placing pressure near the tip of the tone board shortens the vibrating portion of the reed, creating high-frequency yips; moving your lips back toward the wedge lengthens the vibrating area, dropping the pitch into a deep howl.

Does the shape of the horn or bell affect the coyote's response?

Yes, the shape and volume of the horn bell dictate the realism of the call. A natural horn or flared wooden bell acts as a megaphone that adds warmth, depth, and three-dimensional dispersion to the sound, making the call sound like a live coyote rather than a flat, synthetic imitation.

Can I use a 3D printer to make a coyote howler?

You can 3D print the mouthpiece and tone board using high-density filaments like PETG or ABS, provided you print with 100% infill to prevent internal sound dampening. However, the printed tone board face must be sanded perfectly smooth with progressive grits of wet sandpaper to erase print layer lines, which will otherwise cause the reed to seal poorly and leak air.

Elevate Your Predator Calling Craft

Now that you understand the acoustic science and physical blueprints of predator call construction, it is time to shape your own signature sound. Combine premium exotic materials with precise hand-tuning to build a howling tool that consistently outclasses mass-produced alternatives.