Preparing for Sound

When we first created Driving Sounds Magazine, many readers were amazed that installers considered sound treatment vital to a good result. It is much better understood now, but for those who

Preparing for Sound

When we first created Driving Sounds Magazine, many readers were amazed that installers considered sound treatment so vital to a good result. It is much better understood now, but for those who have yet to encounter it, this article describes why it is necessary and how it is done.

Home speaker cabinets are heavy and made from rigid materials. If your speakers at home were made from Cardboard or sheet metal, they wouldn’t work very well. The same can be said for car speakers. To get the best from a speaker, it should be mounted in as vibration-free an environment as possible.

Most car speakers are mounted in the doors. The cavity behind the speaker consists of unnervingly thin sheet metal that is vulnerable to vibration. A speaker projects its best sound from the front-facing cone. However, equal and opposite forces project from the rear of the speakers. These forces can be amplified by whatever surface they bounce off and then reflected to the speaker's rear. When this happens, the force of these reflected or back waves can distort the speaker’s cone or cancel some of the force coming from the front of the speaker cone.

Although creating the perfect speaker cabinet in a car is rarely possible, there are steps that can be taken to reduce the effects of these inherent problems.

Skinz Sound Deadening is a self-adhesive bituminous material that can add both mass and vibration-damping characteristics. It is usually the starting point when making a car suitable for better sound.

Mass is required to prevent low frequencies from entering or exiting the outside car door panels. This has a two-way benefit of quelling noise from outside and protecting your neighbours from low sound emanating from within the vehicle. Vibration damping is drastically reduced due to the stiffening effect of treating thin metal panels. Skinz Sound Deadening is multi-layered using a material with a rubbery consistency sandwiched between more rigid materials. This helps remove any resonance from panels and quietens middle to high-frequency vibration. It is available in two thicknesses, with the lighter 2mm product used to deaden rooves and large panels in vans especially, and the thicker 3mm version used behind the speaker locations in the doors. Skinz Panel Liner also comes in two thicknesses and helps remove panel resonance. This product is often used in motorhomes and camper vans as it adds a certain amount of heat insulation. Panel liners may also be used on the inside door cards to reduce unwanted vibration.

Skinz supplies a product called Wave Diffuser for back waves or reflected sound. Despite its name, this open-cell foam-based product also provides effective sound absorption. The face has a typical egg box profile, often used in a studio environment. This aims to scatter reflected sounds, thus dissipating the energy they contain. Coupled with the absorption characteristic mentioned previously, it effectively reduces speaker cone distortion.

A new dual application is also listed in the growing line-up of Skinz products. This combines some of the attributes of a sound-deadening product and a panel liner. Skinz Pro-Liner is designed for applications where weight and space are of particular concern.

Your installer will select the most appropriate product for your particular needs, but knowing what and how they work is always a good idea when investing in a car audio upgrade.