For the automotive engineer, using a combination of metal and plastic can be hugely advantageous in the design of automotive components and interior trims. As long-standing partners in design, both materials offer a series of functional and aesthetic benefits in terms of weight, strength, cost and in more recent years contributing towards improving fuel efficiency too. The quality of the materials used within the car interior whether they be plastic, metal, wood or leather and formed into console inserts, interior door panels, air ducts or speaker grilles and coverings will leave a lasting first impression, but they will also behave differently over time.

In this article, we apply our 50 years of experience supplying the automotive industry to explore 5 key benefits of choosing metal as a primary material for interior audio system protection.

1. Sound Quality
2. Durability
3. Choice
4. Cost
5. Environmental Sustainability

1. Sound Quality
Small scale and micro metal mesh have been a key feature of car interior speaker grilles, audio and recording equipment for over 50 years, selected primarily due to unrivalled sound attenuation qualities. The process of perforating and expanding metal enables an impressive degree of flexibility when designing the open area specifications to control, limit or maximise the transmission of sound or frequency through the material and optimise the overall sound quality experience. 
2. Durability
Almost by virtue, metals offer near unrivalled durability characteristics, they are versatile and durable in many applications but when used in the form of speaker grilles within automotive interiors the practical benefits of this durability are quickly realised. Correctly treated metal surfaces are relatively scratch, abrasion, UV and chemical resistant, so in effect maintains its appearance for much longer than plastic. Often speaker grilles are typically located in ‘high impact’ areas, nestled within the door interior or near to the door mechanisms, meaning they can be exposed to the elements when entering and exiting the car and subject to impacts from passengers and luggage. In these instances, material rigidity is important as well as speaker system protection. Metal is flexible enough to meet these requirements without compromising on weight or aesthetic appeal.

3. Choice
We often think of metal as a material in itself, but in fact it is a much larger umbrella term for a group of materials with different features and benefits. There is a plethora of different types of metal, as well as various alloys and grades and that’s before we even consider additional variables like sheet size, thicknesses, gauges and protective coatings. The key consideration here is choice,metal speaker grilles can be manufactured in a choice of materials to suit almost any and every application, though lightweight steel and aluminium are the most popular options. Design flexibility does not stop there, metals can be formed into 3D shapes and pressings using specialist mechanical processes, perforating or etching techniques add a finishing touch and can be specified according sound frequency or protection requirements. Furthermore, the addition of decorative features such as badges or logo etching is easily accommodated for corporate branding and personalisation.
4. Cost
When considering cost, the headline upfront price of plastic speaker grilles is a factor that might instantly draw the automotive buyer, but in reality, most cars are designed to last in excess of 10 years, so the upfront cost is a very small part of the bigger picture. Metal interior trim components typically have a much longer lifespan than plastic, so as a direct consequence the lower maintenance costs associated with metal speaker grilles is a compelling argument for longer term cost savings over and above plastic. To put this into context, a damaged plastic grille may require a whole new costly door case, just to replace a damaged plastic grille. Furthermore, scalable production methods associated with producing perforated and expanded metal speaker grilles means that cost is not always directly linked with volume and the cost of prototyping early-stage design options for clients can be kept low.
5. Environmental Sustainability
Is metal more sustainable than plastic? We think so. Most metals can be infinitely recycled, and have a far higher recycling rate than plastic meaning that metal, especially aluminium, doesn’t need to use virgin materials in the production of new material from recycled content, making it a much more circular process.