BOOM BOX

A Quick and Easy Way to Put Some Bass into Your Factory Sound System

Automotive audio has come a long way in recent years. While often we find ourselves eyeing the latest and greatest gadget to hit the scene, we tend to forget that some products are still as useful and popular as the day they were engineered. And one of the products is the time tested ThunderForm subwoofer enclosure from MTX Audio.



There once was a time when all Subwoofer Enclosures has to be custom made to fit into a vehicle. And this was always in accordance with a “custom” sound system, which completely replaced the factory model. Of course in those days, factory sound systems were not all that great to begin with. But such is not the case with modern factory sound systems. Many trucks today come equipped with very good sound systems featuring numerous speakers and in some cases, amplified systems. MTX is one of the companies that realized some consumers wanted to add some thump to their system, without the cost of completely replacing their stock set up. They developed what has become the time tested ThunderForm enclosure, which is engineered to fit specific models of trucks.

The 1.9 cubic foot ThunderForm enclosure comes with either one or two 10-inch Thunder4500 subwoofers, as well has an option for an amplified version serving up 200 watts of power. The enclosures are generally designed to fit under the rear seats of the trucks so as not to take up much of the important cab space. They also come in every factory color to properly blend into a stock interior. But with all that, what makes the MTX ThunderForms so popular is that they easily integrate into the factory sound system. Basically all that is required is to mount the enclosure, then run the wires to the dash. Run the Power Wire to the engine power supply and run the speaker leads to the head unit where they as spliced into the existing rear channel wires.

On the amplified model that we had South Coast Speed & Sound install for us, the enclosure features its own amplifier which also features an EBC (electronic bass control) and pre amp station. A ten gauge fused Power Wire provided in the harness is more than ample to handle the demands of the amplifier. In addition, our 2004 Silverado had the factory amplified Bose system. Rather than splice into the speaker leads from the head unit, we were required to splice into the leads at the factory amplifier located in the center console.

In about an hour the guys at South Coast Speed & Sound had completed the installation of the MTX ThunderForm, showing us just how quick and easy it is to put some bass in the factory sound system. And when you consider the amplified enclosure features it’s own pre-amp with adjustable gain controls, along with the EBC, you can turn the bass signal down on the head unit to make the factory mids sound better, while letting the new pair of 10-inch subs take care of the low end frequencies. For someone looking for some extra kick in their tunes without the high cost of a custom sound system, the ThunderForm is definitely something you need to check out.

MTX AUDIO
DEPT TEN
ONE MITEK PLAZA
WINSLOW, IL 61089
800-225-5689


SOUTH COAST SPEED & SOUND
DEPT TEN
1746 W. KATELLA AVE.
ORANGE, CA 92867
714-628-0400
WWW.TEAMSC SS.COM

Upon arrival at South Coast Speed & Sound, owner Abo Gulkarov removes the MTX ThunderForm from the shipping box. The ThunderForm is a completely self contained component featuring two 10-inch MTX Thunder4500 subwoofers, amplifier and pre-amp built into a single enclosure which in this case is designed to fit under the rear seat of this extended cab Silverado pickup.	MTX designed the 4500 series subs to meet the requirements of the 200 watt power supply, but to be as efficient as possible in the confines of the 1.9 cubic feet of air space inside the enclosure.	The first thing to do was to remove the driver’s side threshold trim to gain access to the factory wire loom beneath it.
Next Abo lifts and locks the rear seat out of the way and clears the area where so the wiring can be ran to the area where the ThunderForm will be placed later on in the installation. One thing to note is that you will still be able to use the factory location for the spare tire jack.	The wiring, including the right and left speaker leads, trigger, EBC and 10-gauge power wire are then placed into the factory wire track and ran forward to the dash. MTX’s instructions ask for the speaker leads to be spliced into the rear factory speaker wires at the rear of the truck, but instead we chose to run them forward to the head unit and splice them there.	The rear of the harness that will attach to the box is routed and given ample extra length.
One of the most important aspects of installing an amplified enclosure is to make sure you have a good ground. Abo grinds away the paint from a small area on the cab floor near the seat bracket and installs the ground cable there using a self-tapping screw.	Moving forward, the harness is ran through the track to where the dash kick panel has been removed. The wires will run behind the kick panel and up through to the dash.	Before going any further, the wires that will run through the dash are taped so they stay together as they travel through the under dash landscape.
To feed the power wire into the engine compartment, Abo uses a special tool, which pokes a hole through the steering column boot. The power wire is then fed through the tool into the compartment where it is easily acquired.	The 20-amp fuse is removed from the power wire. The wire is then attached to the power post located on the driver’s side of the engine.	Back into the interior, the dash bezel is removed to gain access to the head unit along with running the needed wires to that location.
If your system is a non-amplified factory stereo, remove the head unit as shown. If it is an amplified Bose sound system, the speaker leads will be at the amplifier located under the drink holder in the center console.	We had to decide on a location to mount the EBC (electronic bass control). We chose the blank panel next to the air bag on/off switch. In order to install the control in that location, the panel assembly had to be removed.	The small, blank panel was then removed from that assembly and onto the back side, the plastic cross structure was cut out to clear a path for the control assembly.
The EBC comes with a min/max sticker overlay which was placed on the blank panel.	Using a drill bit, a small ¼-inch hole was drilled in the center, which will allow the control shaft to extend through and be secured to the panel.	With that complete, we then move back into the truck where the lower dash panel is removed so the wires can be routed.
The amplifier trigger wire that signals the amp to turn on is spliced into the brown wire leading from the ignition switch.	The factory speaker wires are blue/light blue for the right channel and brown/yellow for the left channel. If you removed your head unit and do not see these wires, you have an amplified sound system. The wires can be easily located under the drink holder of the center console	Here we see the provided RCA high level input wires spliced into the appropriate speaker wires on the output side of the factory amplifier. The RCA wires are designed to accommodate the power from the amplifier and it will not interfere with the amplifier inside the ThunderForm enclosure.
Before we finish with the dash, the last thing to do was to install the EBC into the panel we modified earlier.	Now Abo reinstalls the dash panel sections and makes sure all of the work is secured.
With the dash bezel installed, you can get a quick look at the location we chose for the EBC. It’s nice having a power control like this at your fingertips.	Now comes the part you’ve been waiting for. The MTX ThunderForm enclosure is installed into the truck. The box is designed to form perfectly to the floor to the point that it is nearly impossible to install it wrong.	Once positioned correctly, the RCA inputs, ground/power connector and trigger are plugged into the pre amp located in the center recession of the enclosure. The amplifier will not power up until the 20-amp fuse is installed into the power wire inside the engine compartment.
The ThunderForm also comes with two locations that allow you to screw the box down to the cab floor. It is advised that you mount the box as it will slide forward in the event you have to get on the brakes hard when driving.	And there you have it. A quick and easy way to add a 200 watts of bass to your factory system without losing your rear seating area. The MTX ThunderForm fits perfectly under the rear seat and the finish nicely matches the interior.