How To Make An In-Ear Monitor DIY

The cost of custom in-ear monitors might be out of your budget. So, can you create them yourself instead? This article will share the steps for building your own in-ear drumming headphones at home.

Warning: Not a lot of people try make their own in-ear monitors or IEMs because of the risks involved. You could suffer from deafness or other ear-related injuries. That’s why you should let an audiologist make the impressions. But if you’re confident with your skills, then this is going to be a worthwhile project for you.

Five Steps for Making Your Own In-Ear Monitor

The tools and materials that are necessary for making in-ear monitors will differ for every person. Below are a few possible tools and materials you’ll need for this DIY project:

  • Impression guide from your IEM manufacturer (This is for the audiologist.)
  • Ear impressions
  • Agar-based duplicating gel
  • Brush for your acrylic paint
  • Plastic cups (for the negative molds)
  • Dampeners
  • Dremel (with external drill)
  • Drivers (e.g. Knowles GV-32830 quad driver)
  • Dental tools (excavator or explorer)
  • Disposable gloves
  • Dye
  • Meat thermometer
  • Litz wire
  • Paper clips
  • Paraffin wax
  • Polisher with rubber grinding head
  • PVC sound tubes (2*3 millimeters and 1*2 millimeters)
  • Sandpaper (1,500 or 2,000 grit)
  • Sockets
  • Soldering iron
  • Sound tube
  • Superglue
  • Two-pin female jack (0.78 millimeters diameter)
  • A rotating tray (aids in even light distribution)
  • Utility knife, razor, or hobby knife
  • Ultraviolet (UV) nail curing lamps or any UV light chamber
  • UV-curing resin
  • UV-curing lacquer
  • Wax discs

Step 1: Get an Ear Impression

This step is best left to the professionals because the risk of injury is just too high. Getting a pair of ear impressions for IEM is typically affordable, depending on the audiologist you go to. The cost could range from $40 to $120.

Be sure to print the impression guide, which IEM manufacturers usually provide. Give it to your audiologist during your visit.

Here’s what you can expect when you get an ear impression:

1. Ear Canal Examination

The audiologist will inspect your ear using an otoscope to see if there are no obstructions, deformities, or illnesses that would contraindicate getting an impression.

2. Placement of the Oto-Dam

An oto-dam or otoblock is a small, cylindrical-shaped piece of cotton, foam, or wool that has a string connected at one end. It’s used by the audiologist to temporarily seal off the opening of the inner ear before injecting the impression material. It should be placed beyond the second bend of the ear canal.

With the use of an otoscope, the audiologist will measure the diameter of the oto-dam that’s perfectly fits your ear canal structure. This is a critical step because if the diameter of the oto-dam is too narrow, the impression material could flow beyond the oto-dam and reach the eardrum. And if the diameter is too large, the audiologist won’t be able to place it at the depth necessary for a good impression.

3. Injecting the Ear Impression Material

This is typically a painless procedure. But we just want to give you a heads up that the impression material is cold.

During this time, the audiologist might ask you to do any of these three actions to make sure your impressions fit your ear properly:

  • Close your mouth during impression syringing and curing. While the material is curing, you can just relax or talk.
  • Open your mouth wide before and during the injection of the impression material. You’re not supposed to close your mouth until the material completely cures. Don’t worry. You’re going to use a bite block during this time.
  • The audiologist might also encourage you to chew, talk, and smile while he or she injects the impression material into your ear.

4. Removing the Impression Mold

To break the seal, the audiologist will gently pull your pinna (outer portion of the ear) up and back. Then, the audiologist will remove the impression from the antihelix (the raised, Y-shaped ridge that surrounds the concha) then slowly rotate it forward and out.

In case the oto-dam won’t come out, the audiologist can use the attached string or vent tube to remove it. It’s normal to have slight redness after the audiologist removes the impression.

Note: Before you leave, be sure the impressions (or canal earmolds) have the necessary canal length and show the correct anatomy of the outer ear and inner ear. There shouldn’t be any air pockets.

Step 2: Polish Your Ear Impressions

After getting your ear impressions from your audiologist, you might still need to do some smoothing, shaping, and trimming. Since your ear impressions will determine the final fit of your in-ear monitors, it’s important for them to be exceptionally smooth and have the correct dimensions.

This step is also important because if the ear impressions have a rough texture, your negative molds would also have the same texture. The end result is IEM shells that can irritate and injure your ears.

To avoid this, dip them in paraffin wax. Here’s how to go about it:

  1. The first thing you need to do is to round off the edges and smooth the surface using a hand-held grinder (e.g. a Dremel cleaning and polishing rotary tool), finishing stone (white stone for acrylic and vinyl and blue stone for silicone), or fine sandpaper (1,500 grit or 2,000 grit).
  2. If you need to remove large portions from the impressions, use a hobby knife, scalpel, and/or scissors.
  3. Stick a paper clip at the canal tip of each impression. Put the impressions aside.
  4. Use the double boiler method for melting your paraffin wax. For this method, you’re going to fill the bottom pot with a few inches of water (one or two inches). Then, place in the top pot, pan, or metal bowl.
  5. Once the wax melts, let it cool for a few minutes or until the temperature drops to 70 degrees.
  6. Dip one of the impressions in the melted paraffin wax. Do this only twice, making sure the coating is thin and without lumps. If the coating is too thick, the impression might not fit your ear well.
  7. Repeat the same process to the other impression.
  8. Allow the wax to harden. If there’s leftover paraffin wax, you can pour it into a separate container, so you can use it again later on.

Step 3: Create Negative Molds

After taking out the paper clips from the impressions, it’s time to make a transparent negative mold. You’ll use this mold later on to make a positive shell using UV-cured acrylic or resin.

For this step, you’ll need containers that allow one end to be opened. Or, if you’re on a budget, try using plastic cups. Put the impression at the center and glue it in place using small wax discs or the excess paraffin wax.

You can use agar-agar, or simply agar, for making the negative molds. Agar-agar is a type of gelatin that’s derived from seaweed. Here’s how to prepare it:

  1. Dissolve one teaspoon of agar-agar powder for every four tablespoons of hot water.
  2. After bringing the water to a boil, let it simmer for around one to five minutes.
  3. Let it cure for two hours in room temperature. If you want to cool it faster, put it in your refrigerator.

Important: Agar-agar will not melt if it’s not heated to 185°F to 194°F (85°C to 90°C). However, it’s not also a good idea to boil it for too long beyond the melting point because it can negatively affect its gelling capability.

Once the negative molds have cooled down, carefully remove each impression from the plastic cup. You can use a dentist tool, such as a dental excavator or explorer, or something similar to pry the impression loose.

Then, rinse the negative mold with water to remove any excess wax. Use this time to inspect the negative mold for imperfections. If necessary, make a new one. Fortunately, you can reheat agar-agar up to six times.

Step 4: Create the IEM Shell

The next step is to create the shell formed from UV-curable acrylic. Start by pouring the UV-curable acrylic into the negative mold. Fill it to the brim, but take your time to avoid bubbles from forming.

Ultraviolet light is necessary for curing the acrylic. A good alternative to the sun is ultraviolet lamps for drying or curing gel nail polish and acrylic nails. The overall curing time of your chosen material will usually depend on the UV light source and your ear size. It could last between two to three minutes, or possibly longer.

But before the acrylic completely cures and hardens, pour it out from the negative mold to leave a hollow space for the drivers, sockets, and sound tubes. Put the negative mold back to the UV light source to cure it around seven to twenty minutes. Try to experiment with different cure times to get the right thickness.

Then, take out the shell out of the negative mold. Use a surface cleaner if the shell is slightly sticky.

Smooth out the surface of the shell using a fine-grained sandpaper for wet grinding. Experts recommend starting with a grit ranging from 600 to 1,200.

It’s important to use a light hand to avoid sanding away more material. Apply different sanding motions for every pass to ensure the smoothest finish. Be sure to sand down the bottom, so it’s flat enough for attaching the faceplate later.

Once you’re satisfied with the texture and shape of your IEM shell, you can start drilling holes (around 2.5-millimeter deep) into the ear canal part using a 2.1-millimeter bit. Next, drill holes for the two-pin female jack and damper in the sound tube.

Note: You shouldn’t let the drilling tool drill too fast because it could cause the shell to crack.

Polish the shell again to produce a smooth surface. To give it a glossy finish, apply a UV-curing lacquer. Put it back in the UV light unit for another seven to ten minutes for drying.

Step 5: Install the Electronics

  1. Solder the drivers to the two-pin female sockets. Make sure you solder the positive (+) terminal of the driver (usually features a dot or dent) to the positive terminal of the socket. Likewise, solder the negative terminal of the driver to the negative terminal of the socket.
  2. Glue the sound tube to the drivers.
  3. Gently pull the sound tube into the ear canal tip of the shell until the drivers are completely flushed. Make sure the sound tube stays firm inside and doesn’t kink. Otherwise, it would affect the sound quality.
  4. Cut the tubing just slightly above the canal tip then insert the filter. Apply glue around the filter to secure it in place. The mesh should be pointing at the drivers.
  5. Note: The color of filters indicate the ohm. The higher the ohm (or the impedance), the better the sound quality. However, if you’re only going to use your in-ears for casual listening on your phone or laptop, you can go for a filter with a low ohm. A brown filter (1000 ohms) is a good in-between option. If you like more emphasis on the lower frequencies, go for the green filter/damper (1500 ohms).
  6. Glue the sockets.
  7. Make sure the litz wire is properly coiled, so it doesn’t get in the way of the shell and break apart. There shouldn’t be any tension to prevent short circuiting.
  8. Seal off the opening of the shell by attaching a faceplate (metal, wood, vinyl, etc.) or soldering the other half of the shell. Use the appropriate adhesive.
  9. Expose it to the UV light unit for seven to ten minutes.
  10. Grind the sides of the faceplate, so it follows the shape of the opening of the IEM shell.
  11. Clean the surface with a surface cleaning solution.
  12. Apply a final coat of UV-curing lacquer then cure it in the UV light unit.
  13. Insert the earwax guard.
  14. Plug in the cable into your DIY in-ear monitor and audio source to perform a sound check. If there’s no sound coming out, check the polarity and solder connections.

How long will DIY in-ear monitors last [How Long Do In-Ear Monitors Last]? There’s no specific answer to that question. It depends on various factors, including the quality of the materials you used, the quality of your work, and how you care for your DIY in-ears [How To Maintain In-Ear Monitor].

Conclusion
And you’re done! This is just one example of a DIY in-ear monitor. The materials and tools you’ll need will greatly vary, depending on your requirements. If you need more ideas or have questions, visit popular forums for in-ear monitors [Popular In-Ear Monitor Forums] or ask for help from the company where you get your materials.

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