Simplicity with a focus on installation integrity is the order of the day as far as the passenger compartment is concerned.
In the doors, approximately 30 square feet of B-Quiet Brown Bread sound damping was applied to the inside of each door frame, along each crash bar, and both on the outside door panel and the inside of the door skin. To some, this may be overkill, but to establish the bass presence up front without any nuisance rattles, the amount of damping installed was critical. Once completely damped, the OEM baffle was mimicked in size and shape and a 14-layer birch baffle was constructed to eventually house a dedicated midbass driver in each door. The baffle was constructed out of cabinet grade wood and soaked fiberglass resin to ensure that the baffle was waterproof. Upon completion, each baffle was attached to a secondary piece of �� MDF, also soaked in fiberglass resin, which acts as the mounting ring, and was re-attached to each door using tamper proof hardware. A Morel Elate 6.5� midbass driver was installed in each door at seven points of contact with the door and birch baffle, and the factory door skin was replaced over the speakers to conceal and protect them.
In the kick panels, modifications were made to the OEM trim panel to accept a dedicated midrange driver. This was accomplished by advancing a hole saw through the center of the panel, and then massaging the shape of the panel slightly with body filler so that the speaker would fit flush to the base of the panel. This was accomplished by sanding the kick panels with a very rough grit sandpaper (36 grit) to ensure that the body filler would key into the plastic and not detach the first time it gets hot or the car hits a bump. Prior to speaker installation, a layer of plush fabric was stretched across each kick panel assembly. This was done for two reasons: to provide a gasket seal, of sorts, between the midrange and the panel, and also to decouple the midrange driver from the panel to avoid ringing and help avoid early reflections off of the panel. In each panel, a DLS Iridium series 3� dome midrange was installed with four points of contact to each kick panel using tamper proof hardware. The midrange was angled to propagate the sound waves to the center of the car.
In the center console, 1� thick acoustic foam supplied by B-Quiet was installed on a knock-out trim panel forward of the console on the passenger side, and behind the OEM carpeting on the driver side. The panel on the passenger side was also covered with the same fabric used to cover the kick panels for cosmetics. The foam helps to absorb reflected energy from the kick panels, and ultimately helps to stabilize image focus.
The front stage driver compliment was completed with the installation of tweeters in each a-pillar. Like the kick panel, the a-pillars required a fairly comprehensive re-working to ensure the correct angle could be established for the tweeters. Using body filler mixed with fiberglass matte, the shape of each a-pillar was fabricated so that the tweeters would be firing directly coincidental with the windshield. Once again, fabric was used to de-couple the drivers from their mounting area. Once completed, a DLS Iridium series tweeter was installed in each a-pillar. IXOS 11 gauge Gamma Geometry speaker cables were used to connect all six front-stage speakers
In the dashboard, the OEM deck was removed, and the stamped metal brackets were salvaged for use in the new installation. A Pioneer DEX P-9 source unit was secured into the factory dash location using the OEM stamped steel brackets, at a total of eight points of contact to the car, using tamper proof hardware. JDM glass optic cabling (not the cheap fiber aramide junk) was routed to the trunk where it was connected to the DEQ P-9 processor. To finish the installation, a Metra fit kit was modified by cutting off the plastic mounting tabs on the back of the kit (in lieu of the use of the steel brackets), sanding down the front fascia of the kit, and painting it landau black to match the color and texture of surrounding OEM panels. A fuse for the source unit was installed on the inverse side of the center console, right below the source unit. This location provides easy access but its location behind the map pocket door provides a certain level of security as well.
In the center console, an aluminum bracket was fabricated and painted landau black to hold the P-9 system tuning remote control. The remote control provides easy access to system functionality during Scott�s long commutes to and from work. And the quick release mechanism allows the remote to be removed and hidden for security.
The seats have been modified with custom bent and welded seat rail extensions built by Buwalda. The extensions knock the seats back about 5 �� from the original location. Most people think that moving their seats back will help staging. Most of the time, it�s true, but sometimes, stage width can suffer with the increase in pathlength difference. Fortunately, not in the Altima. The wide stage width was maintained with the seats being moved further away from the speakers. So, why move the seats? It�s simple. There are midrange drivers mounted in the kick panels. The seats were extended primarily to ensure that seated passengers do not block the kick panel speakers with the feet, pant legs, and etc. Of course, the reduction in pathlength difference certainly helped image position as well. Plus, when seated for long listening sessions, you can�t help but think you�re sitting in your living room with the amount of legroom afforded by the seat rails.
Finally, the last items worth mentioning in the passenger compartment are the b- and c-pillars and the rear deck. First of all, to ensure a cosmetic theme throughout the vehicle, even though not required by the Street-X category that Buwalda competes in, the b- and c-pillars were covered in the same fabric that the kick panels and a-pillars were covered in. Not only that, but it is conjectured that the lighter headliner with black dashboard and pillars helps to psychoacoustically draw the eyes upward, possibly improving stage height for some people. In addition to the pillars, the rear deck was modified. First, the OEM logos were removed from the OEM 6 X 9 grilles, and DLS Ultimate Reference grille logos were put there in their place. Additionally, the center deck-mounted brake light was removed when the rear wing was installed on the car. It worked out well, as the third brake light rattled violently on heavy bass tracks (with the subwoofers throwing that volume of air up through the 6 X 9 holes in the rear deck).