Car Audio, Custom Fabrication, Mobile Electronics

LIS Audio October Feature – 1998 Porsche Audio Upgrade

We had a client bring us his 1998 Porsche Boxster convertible to have the audio system upgraded. The coupe had a bit of audio already installed but our client wanted more volume, and to add some bass for a fuller sounding system. It was important that the sound system be audible while cruising on the road at higher speeds with the top down. LIS Audio set out to accomplish these goals! Be sure to watch the video of the Porsche finished up at the end of the blog…

The previously installed touchscreen JVC stereo powered the also already installed Polk Audio speakers. The amplifier that we chose for the upgrade is a DS18 Candy series 5-channel compact amplifier. This amplifier allows us to power all of the interior speakers and subwoofers while not taking up too much space in the front boot. The client and I discussed adding the new amplifier into the same position as the factory amplifier. A compact amplifier was definitely the way to go in order to achieve the results he wanted.

I built a custom amplifier rack to fit into the same position as the factory amplifier but using different mount points. I decided to wrap the rack in carpet that matches the boot covers and I created custom brackets that are utilized with nut-serts and bolts so that the entire mount is solid with low potential for vibration. I created a mount from ABS plastic to secure the fuse holder to the battery mounting plate for ease of access and to insure that it was mounted solid in place to reduce possibility of issues arising. Oxygen free copper wire was also used for the full installation.

When it comes to coupes with drop tops that are stored between the rear storage and cabin, we tend to find that there is not a shared environment ideal for passing bass into the cabin from the rear boot. This presents the challenge of adding enough sub-stage to the boot to account for the issue, or to attempt to squeeze the sub-stage somewhere into the cabin. There was just enough room in this Porsche to “squeeze” in a decent sub-stage. Here’s how I went about it.

After measuring all possible areas I decided the most air space within the fore mentioned parameters (preferences) was just under the top while it is lowered. This small area limited the amount of air space available to construct and enclosure, so I had to get creative in many different ways. We went with the DS18 6” Elite subwoofers that could be wired to 1 Ohm at the amplifier allowing the most potential power output without straining the amplifier. The enclosure being constructed of mostly ½” MDF wood, in order to save on cost, needed to be shaped to fit the area and the subwoofers.

It proved to be a bit of a task to locate subwoofers that would not only fit in the position with material around them, like wood but, it was important that they didn’t move too much causing them to hit the top while it is down. I used a single Mobile Solutions template to create a Porsche enclosure template, as seen in the pictures. The lower padding in the engine cover was removed just to give subwoofers a bit more room to move. Hushmat sound deadener was also added to the engine cover to reduce vibrations and to help keep any residual heat in the engine compartment.

The subwoofer terminals needed to be modified in order to fit the enclosure without cutting additional slots into the mounting holes. ABS plastic was used to cap the subwoofer magnet cavities, with allow the subwoofers to sit lower then the very top edge of the enclosure. Building these simple aspects into the enclosure gave the subwoofers the perfect amount of room to move. I also included a waterproof quick disconnect for a nearly effortless removal of the entire enclosure whenever desired. I wrapped the enclosure in some nice vinyl that matches the interior of the Porsche very well.

I decided to add a small red accent to the front with the enclosure just under the roll bar to give it a factory integrated feel. The little subwoofers make quiet a difference in the audio system once installed. With the top down they are expected to be a bit muffled by the top and have more output with the top up, which was the case. Nonetheless, the sound system sounds much more full than it did previously. My favorite part about this build is that it is barely noticeable that there is an aftermarket system with the top down, other than the sound that can be heard blasting from the cabin! Those small subs pound!

Check out the video of the installation here and don’t forget to Subscribe!

Thank you for reading our LIS Audio Blog. Stay Tuned next month to see which build, or installation, makes the next feature. Who knows, it could be yours!!

Contact LIS Audio if you have any questions… 

Phone: 913-912-6990


Address: 631 S. A-Line Dr, Spring Hill, KS, 66083

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