Fiberglass enclosure and amp install

[MrTej]

First off, thank you to everyone who has already posted information about installing stereo components into your new rides over the past year. I found a lot of useful information that saved me time, headaches, and money for replacement parts!

I built a custom fiberglass enclosure in the left rear corner of the trunk and installed a JL Audio 10W3V3 that I had from a previous car. I also installed a Kicker CX300.1 mono amp in the spare tire well.

I followed instructions from this website to build the enclosure:

http://chris.pfharlock.com/glass/

I've used these instructions for three different enclosures in as many cars and they have worked well every time.

I'll post replies in this thread to show some of the things that I did slightly differently than others during the install, and to describe the problems I encountered and what apparently resolved those problems (so far!)

But first... the pictures!

Enjoy

Sponsored

 

[MrTej]

Ground location

I chose to use the empty threaded hole on the left side in the spare tire well as a grounding location. The threaded hole on the right is the one that is used to clamp down the foam piece with the tire inflation kit in it. Since this picture was taken, I have sanded the area down to bare metal.

 

[Niz55]

Great job!

 

[MrTej]

Tapping the rear speaker wires

I tapped into the rear speaker wires for the sub install. I've read mixed reviews about using them but after resolving the problems I encountered and tweaking the amp settings, I have good sound and no bass roll off at higher volumes. More on that later...

I tapped into the same wire loom that others have described, however, I tapped into the loom further down on the right side of the trunk behind the carpet wall. It was easy to get to with the rear seat down. This way, the tap location and the new wires are hidden from view. I soldered the connections and then taped them up, and then ran electrical tape around the portion of the loom that I exposed.

 

[MrTej]

Bass Rolloff/Other issues encountered

The amp that I am using has high and low level inputs. Originally, I decided to try and use the high level inputs. The amp still uses the RCA inputs for the high level so you have to use a speaker wire to RCA adapter, which I bought the Kicker one with the amp. There's a button on the amp that switches between high/low level inputs. I set it to high.

I wired up the adapter along with everything else and the first time I turned on the stereo I thought I wasted money and time. It sounded HORRIBLE! Big time bass rolloff. I tried tweaking different settings on the amp and nothing worked. Then things started getting worse...

After the install I drove the car to run an errand. When I got back into the car to leave the store, it wouldn't start! The starter kept turning over but it would not fire. The first thing I thought to try was to pull the fuse under the hood on the 4 gauge wire than I ran to power the amp. As soon as I did that, the car started right up.

The first two things I tried to resolve the issue were:

• Change the location of the power wire in the fuse block- I originally had it bolted down on the first bolt, closest to the battery. I noticed when connecting to this one that most power to the car was cut (I had to reset the date and time, and the lights would come on upon re-connecting). I moved it to the second bolt but it did not resolve the problem. However, it did prevent the car from losing power, so that's a plus.
• Made sure the ground was good. I sanded the grounding location down to bare metal. Definitely needed to do that but still did not resolve the problem.

I noticed during troubleshooting that the voltmeter gauge in the car showed the voltage around 13 volts when starting the car (when it would start), and as soon as the amp kicked in it would drop to 12 volts. That is definitely not good- it should be over 14 volts pretty consistently.

I also noticed that the lights on the amp were doing some weird things with the current setup. When it first turned on, it went into protection mode for a few seconds, then went to "green light" status. When turning the car off, it would stay in normal mode and would not turn off. Just for kicks, I disconnected the RCA cables and it would shut off. Plug 'em back it and it went back into protection mode. Very strange.

Almost out of ideas, I decided to run to Best Buy and pick up a LOC- cheap $15 one was all I could find. I figured I'd give it a try and see if anything changed and...

HOLY COW what a difference! All of the previous issues went away. The car starts fine, the amp turns on/off appropriately, the voltage is a steady 14 volts with or without the amp running, and no more bass rolloff!

Before I could definitely tell when the rolloff would kick in, around volume 15-17. Now I honestly don't notice any rolloff at all. I added the available bass control knob for the Kicker amp with the presumption that I would need it to combat the rolloff, but I find that I only need it to adjust settings when going from a current hip-hop or rap song to an old rock song recorded 30 years ago.

I have absolutely no idea why this worked but it did. I did not adjust the gains on the LOC out of the box at all. I only adjusted the gains/bass boost/crossover point on the amp to a reasonable setting at high volume. The part that really baffles me is that just by using the high-level input on the amp, the car wouldn't start! (This was random, by the way. But once it got to the point where it wouldn't start, it wouldn't start at all until I pulled the fuse.)

Last resort would have been to tap the front speakers, but since everything seems to be fine now I'm going to hold off on that.

 

[ib2loud]

I used an amp with high level inputs and haven't had those issues but do notice the rolloff. I have a LOC on the way and this gives me hope.

 

[gundam83]

Looks good!

 

[Chameleon]

The sub enclosure looks great.

 

[BrantMcE]

Saw the write-up you linked to. Looks pretty intense lol. If I were to go that route I'd definitely try to make a mold for the half that is against the side of the car so I could make multiple without risking the interior more than once.

Now my question is, most subs have an ideal volume of air for inside the enclosure to ensure optimal performance, how did you measure the volume of the enclosure? Or was it not a priority for you? The only method I could think of is to fill it with water and measure how much water it takes to fill it.

 

[MrTej]

Saw the write-up you linked to. Looks pretty intense lol. If I were to go that route I'd definitely try to make a mold for the half that is against the side of the car so I could make multiple without risking the interior more than once.

Now my question is, most subs have an ideal volume of air for inside the enclosure to ensure optimal performance, how did you measure the volume of the enclosure? Or was it not a priority for you? The only method I could think of is to fill it with water and measure how much water it takes to fill it.

Yeah it's definitely intense lol. This is the third one I've done, but the first one that I had to lay glass on the top side of the enclosure. I was worried that the fiberglass was going to fall down before it dried, but it didn't. I ended up not getting it as thick as it should be been working inside the car, so once it dried I removed it and finished adding layers. I used an entire roll of frog tape in the car to make sure that nothing leaked, and nothing leaked . I would recommend using Scotch blue tape, though. The frog tape was a bear to remove from the enclosure after I got it out. And definitely lay plastic down in the trunk and wrap it around to the outside of the car.

As for the sub volume, the one I am using needed a little more than a half a cubic foot of air, which makes for a pretty small enclosure. Being that this was the third one I have done using the same sub, I was confident that the space was going to be more than enough for the sub. And it definitely is enough space for my application; it sounds great.

Here are a few shots from laying the fiberglass inside the car:

 

[UWISHU1]

nice work,PM sent

 

[Ap8823]

How does it sound compared to the shaker? I have the 12 speaker shaker with sub and need more bump

 

[MrTej]

How does it sound compared to the shaker? I have the 12 speaker shaker with sub and need more bump

I haven't heard the shaker system but I am definitely not lacking any bass. After listening to it for awhile now, I can tell where the rest of the stock (non-shaker) system falls short. It has very little mid bass range, or at least the lack of power in the stock system as compared to the sub makes it appear that way. I'd like to add another amplifier and upgrade the stock speakers, but my fear is that amplifying the stock signal won't do much good overall. I'm waiting to see what aftermarket options come out for the head unit, or maybe try something like the JL Cleansweep to get a clean signal.

 

[ConspicuousConsumption]

Come on over to VA and show me how to do it. I need friends like you.

 

[NotMarc]

Sorry to revive this thread from the dead, but OP's last active well over a year ago. Is anyone else taking on this project? I've seen a couple on Youtube, and would be willing to buy one second hand depending on interior volume.

Sponsored