The first step in one of our custom installations is prepping the vehicle. Areas of the car that will see a lot of traffic, like the back bumper, seats, running boards, etc. are covered in tape or plastic sheeting to protect them during the entire installation. We use these wire carts to organize the equipment going into the car, and the parts coming out during installation.

2013 Volkswagen JettaWhen taking on a specific car for the first time, it is important to analyze the audio signals from the factory radio to ensure they will be suitable for aftermarket components. Most cars use some form of built-in EQ to make up for the shortcomings of the factory speakers. When the rest of the equipment is upgraded, the EQ curve is still there and can make the new gear sound even worse. This AudioControl RTA is listening to the audio signal between the radio and factory amplifier. The response after the factory amplifier has a heavy EQ curve, but as you can see to the left, the response out of the radio is flat. This is ideal for our purposes.

2013 Volkswagen JettaNow that we have found a level audio signal, it is time to see how strong it is. Playing a 1 KHz tone through the system and listening on the wires with an oscilloscope shows how strong the signal is, in volts. It also shows clipping-when the audio begins to distort-which in this vehicle is never. On a clean signal, the maximum volume level has no distortion. At the maximum level, it also has 4v of output, comparable to a high quality aftermarket radio.

2013 Volkswagen JettaThis Jetta was built with the “Fender” audio system, Volkswagen’s premium audio system. The speakers are completely different drivers than normally found in the Jetta. In the doors are dual voice coil 6.5″ mids that are riveted in place in classic VW fashion. What is different is these speakers also have a slimy layer of butyl rubber to give them a good seal. To remove the speakers, the rivets need to be carefully drilled out and the speaker pryed from the panel. The speaker has the mounting flange near the back of the speaker, so it sticks out about an inch from the panel.

2013 Volkswagen JettaWith the factory speaker removed, we cover the metal surface behind the speaker with Black Hole tiles. These thick brownie like squares disperse the back wave of the speaker to eliminate vibrations in the outside skin of the vehicle. We have removed all of the factory rubber slime on the back of the speaker, but and will use our own butyl rubber to seal the speaker to the door panel.

2013 Volkswagen JettaTo mount the new Hertz speakers, we machine spacers out of layers of ABS plastic laminated together. The rings are covered with a layer of butyl rubber to seal them and bolted through the original four holes. Then mounting holes for the Hertz speakers are drilled and tapped into the plastic. Finally, a set of hex head machine screws hold the speaker tightly. Finally, a ring of open cell foam is adhered to the front of the speaker, so the entire front side of the cone is sealed through the factory grille opening. This way, none of the sound is wasted in the space between the speaker and the door panel. It may not seem like much sound would be lost in there, but in a A/B comparison, the loss is significantly noticeable.