My business started over 10 years ago in my dad’s driveway building out trunks for friends for $15/hr. And now one of my very first major customers from the driveway days is back: and he wants a full vehicle audio build in my shop. “You know you’re the only one I’ll ever let touch my car” he says. Awww, he’s just buttering me up so I give him a discount.
Classic car: a 4th generation Nissan Maxima. Years 95-99, I’ve owned two, he owned one, that’s actually how we met back in the day. It’s a fantastic car with a fantastic motor and, in my humble opinion, the best generation Maxima ever constructed. He loved it so much that he found another one (1999) in great condition and decided to have it built out while he drove around his original. Maximas for life.
The objective was loud, clear, clean, maintain trunk space, and a tablet as source. I was okay with everything but that last part. But it’s not my car, so I bite my tongue and get to work.
Starting with the front doors. First step was to treat the outer door skin in Stinger Roadkill Extreme and the inner door skins in Stinger Roadkill Ultimate, which is a dual layer damping material. Mounting plates for the speakers were machined out of expanded PVC and the crossovers were mounted via RivNuts and machine screws to the door. FastRings were used to couple the speaker to the door panel. Arc Audio ARC6.2 components were the speakers chosen for the front stage because they can handle a ton of power and still sound phenomenal.
Obviously, the other side was given the same treatment:
The factory center stack:
This is the part I wasn’t too keen on. Customer provided a tablet and a mount created by another shop. The tablet fed an Arc Audio ALD Line Driver which fed into the AudioControl 3Band EQ for an external volume knob that fed the amplifier in the trunk. The other component to this system was a cheapo lil Bluetooth module that he wanted flushed into his dash. Okay, I do these things.
Dash all assembled with the new goodies:
As a sidenote, I couldn’t stand how crappy his wiper arms looked so while I had the car I decided to remove them and send them off to powdercoating for a gloss black finish. Yay. More better.
Time to address the rear doors. He wanted rear speakers. I hate rear speakers. But it’s not my car, fine, I’ll put in rear speakers. First I took the door apart for deadening. Stinger Roadkill Extreme was used for both the inner and outer door skins and Arc Audio XDI 4″ components were installed. But first the grilles had to be dyed to match because that black/silver color combo would have stuck out like a sore thumb on this car.
And now for under the hood! The original battery was replaced a Stinger Absorbed Glass Mat Battery, the SPP1300C. The new battery box was welded into place to securely hold everything in place. The grounds were upgraded and all power wiring was switched over to ring terminal. Looking good!
Time to get some parts out of this car! The rear deck and trunk trim all needed to be removed.
All new speaker wiring was run from the speakers to the trunk along with power wire and three sets of RCAs. All wiring products were Stinger Electronics. The amplifier chosen for this install was the Arc Audio XDI1200.6 which is a super efficient powerhouse.
A subframe was welded up out of 1″ steel square tubing and RivNuts and machine screws held it in place in the spare tire well. A floor was made of 3/4″ MDF and upholstered in carpet to mount the amplifier.
Time to get this beast wired up!
I welded up a 1×2 steel subframe to mount the subwoofer box. This provided a level and secure mounting point via a wooden U-Channel secured to the underside of the box.
While I was back there, I put a double layer of sound damping material on the trunklid to make it solid and reduce vibration.
Time to start on the subwoofer box construction. First step is to design a desirable response curve with WinISD to determine how the subwoofers will behave. Here you can see a sealed box vs two different ported enclosures under consideration.
Let’s get building!
There’s still a few variables that I leave to ‘on the fly’ calculations when constructing an enclosure. I have an intended volume of the enclosure before I cut my first piece of wood. However the depth of the box was going to be determined by the notches in the rear as well as a seat belt notch on the top of the box. Once I set an optimum depth of the box and that is constructed, I build my center brace to zero in precisely on my target air space. This allows for an EXTREMELY accurate design… In this case, with a margin of error of 0.16 cubic inches! The ports were designed to be precision mounted and still serviceable so they have mounting flanges sealed with a small amount of silicone.
It was at this point that the project was officially named GMO-RILLA. You got King Kong in your trunk? That’s cute. I’ve got a modern-day genetically modified freak of nature knocking around in my trunk.
The enclosure was then fiberglassed inside and out before being installed in the trunk.
The ports were installed through the rear deck and steel brackets were made for the backside of the box for additional support. Subwoofer wiring was run and sealed.
Here’s a mini-montage of the trunk trim-out woodworking:
Vinyl went down on the sub box and then the pair of Rockford Fosgate P2 12″ subs was installed so I could start enjoying the BOOM BOOM. Once they subs were in, the floodgates were opened for wrapping up the trim out on the trunk design and getting fabric down on everything. The whole trunk is built for ease of maintenance: panels are held together with magnets and press fit joints. A breathable viewing window allows access to the amplifier.
Testing fitment and testing lighting…
The final pieces were upholstered in a tan suede to add a splash of complimentary color to the black vinyl and trunkliner carpet. Everything then just went together and the trunk was complete!
COMPLETED TRUNK BUILD:
Time to address the rear deck. The original was used as a template to create a new rear deck from scratch out of 1/4″ masonite, pieces of chamfered MDF, and a machined acrylic logo insert to officially brand the project. The deck was upholstered with matching tan suedeliner and looked super fly when it was all done.
COMPLETED REAR DECK:
And as one last final touch, I had to make sure that when you folded down the arm rest to access the ski-hole, you wouldn’t see the ugly backside of the subwoofer enclosure. Sooooo….
The vehicle lived up to its name and was insanely aggressively loud yet still remained clear. We have the future revision currently in the works to replace the ALD + EQ with a Sony H/U to help improve sound quality and usability. This install was an absolute pleasure and I can’t wait for the next phase!
Hope you enjoyed!