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· Registered
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Discussion Starter · #1 ·
I realize that this is long overdue, as I built the system back in 2008. However, I figured I would share some of my build notes. This write up is mostly from my blog, but check out the site for more (and bigger) pictures: http://protolounge.com/projects/2001-nissan-sentra-audio

Head unit: Pioneer Premier DEH-P480MP
Amplifier: Xtant X603
Front Speakers: Infinity Kappa 60.7CS 6-1/2″
Rear Speakers: Infinity Reference 6012si 6-1/2″
Subwoofer: Image Dynamics IDQ10 D4 v.2

Subwoofer Enclosure

The sub box was, by far, the most difficult part of the installation. I wanted a clean install, and I wanted to be able to use my trunk. I found that the corners of my trunk had notches carved in to the sides, which would perfectly fit a shallow 10-inch subwoofer enclosure.

I lined the trunk with plastic and covered the driver-side notch with tin foil. This provided protection while I slathered on resin and patches of fiberglass. After a good 2-3 layers of fiberglass (letting each layer dry before putting on the next), I pulled the enclosure out of the trunk.

I applied another 5 layers of resin to the inside of the enclosure and let the whole thing dry. I tested the volume of the enclosure by filling a 1′ x 1′ x 1′ box with packing peanuts and pouring them into the enclosure space. Image Dynamics suggested a 1 sq.-ft. volume for a sealed enclosure, so I needed to be sure that the space was right.

I cut a wooden ring that would hold the speaker, but while performing this procedure, I managed to cut the corner off my friend’s chair (Sorry Zac! I promise to use real saw horses next time!). Wooden dowels were used to raise the ring above the back of the enclosure, and a cut up t-shirt was pulled over the ring and glued to the enclosure. Then, 7-8 layers of fiberglass and resin were applied to the top of the t-shirt material.

Once the box was completely dried, I cut a hole using the ring as a guide so that the speaker fit into the casing. I then used a bit of spackle to smooth over the rough bits on the enclosure. Using some 3M spray glue, I carefully carpeted the front of the enclosure, which gave it the appearance of belonging to the trunk.

Trunk Floor

After carefully test fitting the sub enclosure, the trunk floor was next to be constructed. When I was first deciding on how best to fit all of the components, I noticed that the stock trunk floor was nothing more than a thick piece of carpet, which would not hold the weight of the amplifier or subwoofer. That certainly would not do.

I laid the original trunk floor/carpet over some medium density fiberboard (MDF) and traced the outline, leaving a notch for the sub enclosure. Because access to the spare tire was necessary, I cut a simple trap door out of the new floor and carpeted the pieces individually. I attached a piece of nylon strap (I believe it was stolen from a duffel bag) to the trap door to allow for easy access.

Amplifier Box

I realized that I needed something to hold the amplifier. While I could have just bolted the large Xtant to the trunk floor, I would be worried about something slamming into it and hurting the electronics or the pretty chrome finish so I built a box.

I assembled the box with screws and Gorilla Glue. The box was created with two layers of MDF which allowed me to put a lid on top. This lid, however, would not be as basic as the trap door on the trunk floor. Oh no. I needed something more…shiny. Using a 3/4″ thick piece of Plexiglas and a laser engraver, I carved out one of my favorite sketches from a cartoon: TROGDOR THE BURNINATOR. I was proud. The engraved Plexiglas was set into another piece of carpeted MDF to form the lid.

I spray-painted the inside of the box black to mask the MDF and added four 80mm computer fans with grills to the sides of the box. The fans were strategically placed to allow air to flow into the amplifier’s heat sink intake and out the opposite side. Using a relay, I wired up a switch to the side of the box and added some cold cathode tubes to emit glorious blue light on the amp, which invariably increased the “bling” factor of the car tenfold.

Finished System

Wiring the rest of the system was quite involved. The sheer amount of speaker and power wires to install was daunting and took some time but the process was fairly strightforward. I replaced all of the component speakers and the head unit. I also routed a large 12V line from the battery through the front bulkhead of the car to the trunk. Finally, I connected all the speakers and switched everything on. Thankfully, nothing exploded.

After tweaking with the amplifier and head unit settings (crossover, fading, etc.), a cascade of rich sound washed over my ears. No longer would my commutes be dull and filled with garbled, flat notes! The glorious, deep, vibrant sounds of music were emitting from my speakers.

No project is complete without its lessons learned, however. As for the installation process, here are a few tips:
  • Be careful prying open panels. You’ll probably break a few tabs. If you break all of them, the panel doesn’t hold anymore, as evidenced by my floor scuff plates.
  • If building a trunk floor, try to use a solid piece of MDF and make sure not to leave any thin parts. If someone rear ends you, the trunk floor needs to be strong (unless you feel like replacing it).
  • Fiberglass and resin are massive pains. Wear a sealing mask and buy plenty of latex gloves.
  • Label everything. A little piece of masking tape and a pen will help you remember which wire goes where.
  • Measure twice, cut once. This old adage certainly holds true. Make sure you have everything carefully designed and measured before cutting and building
My thoughts on the sound, which is some complex combination of individual speakers, amplifier settings, and car acoustics:
  • All around vibrant and clear, if a bit bright.
  • Highs can be harsh sometimes – I will likely go for silk tweeters in the future
  • The subwoofer is quite punchy and replicates drum sounds quite well. It is a bit lacking on the low “rumbling” of hip-hip and techno songs but good enough to shake the car a bit (this is a shallow 10″ sub, after all).
  • Soundstage was quite good (for a car). If I stuck my head in the middle of the dashboard, I could “see” where the different instruments were placed on the stage. Since I’m driving on the left side of the car, this becomes moot, though.
In the end, this was a fun project, and I learned a lot about audio systems and car electronics. This was my first build, so I am by no means an expert, but comments and questions are welcome.

· the only 500whp spec-v
2,243 Posts
not bad at all for a first build. you had a solid idea but not the best tools or knowledge to go about it and maybe the best material choice. that ID sub would do great with a little more air space. ive used ID IDQ subs for years and love them. packing peanuts are a bad thing to use to measure air space because the settle. sand would give you a much better measurement.

all in all nice build, maybe by now you have rebuilt it?

· Registered
8 Posts
Discussion Starter · #3 ·
Yeah, my tools were definitely lacking, and I've learned a lot in the process. I would certainly do things differently next time. Good call on the sand - I was afraid to use water (well, the resin/fiberglass would be fine....not necessarily other things).

I've not had a need to rebuild it - it's been working great for me. The only thing I've replaced was the head unit. About 2 months ago I upgraded to an Alpine CDE-HD137BT. It has a bit better sound and more features than the Pioneer, but I actually like the interface on the Pioneer more.

I'm sure my next car will see a similar-but-much-improved sound system :)
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