Did you ever wonder, what is the best material for IEM manufacturing? Or, why do brands choose one particular material for making their new IEMs? Choosing the right material not only effects sound but also some other factors are involved too like cost, looks, and personal preferences. I am talking about mostly the outer shell material in this article like plastic, acrylic, resin, and metal. Each has its pros and cons so let’s discuss them.
ABS/PBT plastic is the most widely used material in the manufacturing of the outer shell of IEM. Plastic, either totally or in combination with other materials (steel/aluminum) is used in most of the IEMs from big to small audio brands so far. The plastic outer shell has the least impact on the tuning of the sound so manufacturers don’t have the opportunity to utilize the benefit of IEM’s body while tuning the IEM. Here are the major pros and cons of using plastic as the outer shell of an IEM.
- Cheap (Price),
- Easy to design,
- Easy to do mass production,
- Variety of color options,
- Can be molded in any shape,
- Highly customizable.
- Not durable,
- Look and feels cheap,
- Easy to get scratched.
Acrylic & Resin
Acrylic and resin have become popular recently and lots of manufacturers moving from plastic to acrylic and resin. Though acrylic and resin’s outer shells don’t have any sonic impact on the tuning if these IEMs shapes can be perfectly designed, you can achieve a good fit and hence good sound too. The main attraction of acrylic and resin is customization. Those IEMs can be highly customized according to the user’s personal needs. Like you can get your favorite colors, your name embedded, any artwork or an exact copy of ear canal shaped nozzle. Still, there are pros and cons present in acrylic and resin shell IEMs.
- Moderately cheap,
- Highly customizable,
- Doesn’t require huge machine or assembly line to manufacture,
- Premium looking.
- Moderately scratch resistance.
- Still not durable like metal,
- Still require metal parts in the shell (Nozzle, connectors),
- Requires good craftsmanship to achieve good results,
- Can be allergic to your skin if the resins not cured properly, or very low-quality resin used.
- Resin body IEMs, can introduce hair line cracks if the resin is not good in quality.
When comes to designing and manufacturing IEM using metal, (Stainless steel, aluminum, & magnesium alloy) is mainly used. Making IEM shell/parts from metal is maybe the toughest job as hard metals are not easy to mill/cut or mold. Soft metals like aluminum and magnesium alloy are still not soft to shape by hand. Metals shells have a huge impact on the overall tuning and some brands like Campfire Audio even use their proprietary composition of metals and internal acoustic designs to achieve the superior design. Here are some pros and cons of using any kind of metal in IEM’s shell development.
- Premium looking,
- Acoustic advantages,
- Hard to mass production,
- Not lightweight,
- Limited colors,
- Can get scratched or color can get faded over time.
From the consumer’s perspective, IEM made out of any kind of metal is more desirable due to their durability but those IEM’s cost was an issue. Recently some brands like TRN Audio, Tin Audio & BQEYZ debunked that myth, and all of their products are made out of metal still being very inexpensive. Wood is another very good material for designing any sound related products but Wood needs extra care, hence the manufacturer using it less. Now we can see, every material has its advantages and disadvantages but resin and metal IEMs are my favorite.