Tutorials: Full Sound System Upgrade (Part One)
- Saturday 4th December, 2010
Here at MEA we know that many of our readers are keen on rolling their sleeves up and getting stuck into their own installations, so we thought it was a great idea to tackle a full system replacement ourselves and guide you through each step of the process. Each stage of this car’s build will show you how to tackle the basics of audio installation in a typical system design that doesn’t require any fabrication or expensive tools. This type of installation can be attempted by even a first time installer and should only take you a matter of two days to complete.
The brief for this installation was to offer the car’s owner a significant upgrade in every facet of performance demanded by a modern technology user. That means, not only does the sound system need to be far higher in sound quality and SPL capability, but it also needs to cater to all the modern connectivity conveniences. These include iPod and iPhone, Audio-visual, Bluetooth hands-free, navigation, and even the retaining of the steering wheel mounted controls.
If there’s any manufacturer that can link together an entire system design to meet that brief its Pioneer, and after spending a few minutes browsing their website I settled on this list of equipment:
Source unit – AVIC-F920BT $2999 RRP
Main Amplifier – GM-D9500F $469 RRP
Subwoofer Amplifier – GM-D8500M $599 RRP
Front Speakers – TS-D1720C $399 RRP
Rear Speakers – TS-D1602C $269 RRP
Subwoofer – 308D4SB $349 RRP
The car in question is a 2005 Subaru Liberty sedan equipped with the factory fitted McIntosh ‘high-end’ sound system. The Liberty is a great example of the hundreds of thousands of up to ten year old cars on our roads that are desperate for an upgrade. Sure, the McIntosh sound system was half decent when this car was new, but it is literally prehistoric in its abilities compared to today’s latest gear. The demands for a modern sound system have moved in leaps and bounds in the past half a decade.
To head up the system we’ll be using Pioneer’s premium A/V source unit - the AVIC-F920BT. At an of RRP $2999 this is a very serious bit of kit, and probably the most advanced source unit Pioneer has ever released in Australia. As a technology centre piece the AVIC wants for nothing, offering the owner a fully integrated solution to both multi-media and connectivity. Assisting will be a PAC Audio SWI-PS steering wheel control adaptor, linking the steering wheel controls to the AVIC-F920BT’s rear mounted control interface. These are available from Stinger Australia at www.stingeraustralia.com.au.
The Liberty will also be treated to a full speaker and subwoofer upgrade, which of course entails swapping out the wimpy factory amplifier system for some more beefy Pioneer units. In this first stage of the project I’m going to install Pioneer’s GM-D9500F 4-channel and GM-D8500M mono amplifiers.
These two new models are the latest ‘power density’ pairing from Pioneer, serving up healthy doses of power from very compact chassis that are designed to make installation far easier. The GM-D9500F 4-channel will provide 75WRMS x 4 into 4ohms, while the mono GM-D9500M will rocket out 600WRMS at 2ohms for our single 12-inch subwoofer.
List of tools:
- Socket set
- Screw driver set
- Wire cutters
- Soldering Iron
- Electrical tape
- Hole saw
- Cordless drill
Step 1: Removing the car’s interior
The very first part of any installation project is to disconnect the negative terminal of the battery. This is a safety measure that will avoid you inadvertently setting off an airbag or causing a short circuit prior to checking and double checking all connections when reconnecting the battery at the end of the installation. You might want to check the factory CD tuner has ejected the CD before you do it though.
Removing the front seats opens up a huge amount of room and maneuverability around the cabin to work in, but I like to leave the rear seats in place for somewhere to sit otherwise you’ll be crouched over for long periods which is bad for the lower back. With the Liberty the removal of the seats unearthed the OEM multi-channel amplifier and its associated wiring loom. It is here that we will be tapping into the car’s wiring to reach the main speakers, so the new 4-channel GM-D9500F Pioneer amplifier will be placed here. On the opposite side will sit the GM-D8500M mono amplifier to power the new subwoofer. If your car doesn’t feature a factory fitted external amplifier you’ll be required to run front and rear speaker wires from the rear of the OEM source unit to the new amplifier’s location.
Step 2: Running the main power wire
The total system power of the new amplifier pairing is around 900WRMS, and with a cable run of around 2.5 meters, I used a 4-awg main power cable to allow sufficient current supply. The power wire must pass through the car’s firewall via a rubber grommet to protect it from shearing and causing a short circuit, and it also pays to cover the wire in worm tubing to further protect it in your engine bay while keeping the appearance neat and tidy. An in line fuse holder is placed as close as possible to the battery’s positive terminal to protect the car from short circuits in case of an accident. For now the fuse is not placed into the fuse holder as we’ll do that last prior to firing up the system. When the cable is run make sure to securely cable tie it along its path – which should be via a route that avoids anything hot or any moving parts, obviously.
Step 3: Power wire routing and distribution
With the main power wire now run into the cabin the next task is to find the shortest possible safe path to the amplifier location that avoids the RCAs and, if possible, any of the car’s computers. I found a neat path directly down the passenger’s side sill panel that utilized some existing wiring clamps that were unused. This brought the thick 4-awg cable all the way to the middle of the car near to the location for the 4-channel GM-D9500F amplifier. Under the carpet I terminated the 4-awg at a simple power distribution black and split this off into two 8-awg cables for shorter runs to each amplifier. One 8-awg was run under the centre console across the centre of the car to under the driver’s seat.
Step 4: Finding an earth point
Finding a sufficient earth point is essential to properly completing the electrical circuit. If you’re thinking about using a seat bolt or seatbelt anchor point don’t do it. It’s not only illegal to do this but unsafe and ultimately not as great an earth point as it may first seem. Most modern cars will feature numerous additional 10mm bolt holes that are free to use. I found one lurking under the centre console that was ideal for the task. After soldering the earth cable to the terminal ring I sanded back the chassis directly beneath the bolt to expose the bare metal and secured the earth cable into place. Like the power cable this splits into two cables to feed to each amplifier. Since the earth cables are far shorter it is sufficient in this case to use individual 8-awg cables directly to earth.
Step 5: Removing the OEM source
Removing any OEM source unit will entail unclipping various pieces of trim including the gear knob surround and dash fascia, with often as many as a dozen securing screws that need to be found and removed during the process. Many dashboard schematics are available online if you do a little Googling like I did, or of course you can ask on MEA's forums. Once the OEM source is unbolted it will have one or more plug in looms attached as well as an antenna lead which need to be removed. Now you can consider the pathways for the RCA and trigger wires that must be run from the dash are to the amplifiers. If you’re tapping into the factory wiring loom to access the speaker wires at the dash you’ll also be running speaker wires with the RCAs as well. If so it makes sense to mark the ends or each pair of RCAs and speaker wires numerically to assist with connections later on.
Step 6: Running RCAs and trigger wires
RCA leads are commonly available in various lengths, and the key here is to only purchase leads that are long enough to reach the amplifier and not longer than this. Having an extra two or three meters of RCAs bundled up under the carpet is messy and increases the likelihood of induced noise into the system. I’ve used Jaycar sourced two meter twisted pair RCAs with integrated trigger wire as I’ve found them to be the noise free, and affordable RCAs. I marked one of the two leading to the GM-D9500F 4-channel with some white tape to assist with identifying them during connection. The shortest path possible between the source and the amplifiers was straight down the transmission tunnel.
Step 7: Adapting the OEM wiring loom
The OEM wiring loom for speaker outputs is where you can tap into the wiring to connect the amplifier’s outputs to each speaker. There's no great merit in running new speaker wires to the doors as the gauge used by the factory is more than sufficient for 99% of purposes. For this stage you will need to have removed the door trims and OEM speakers to see which colour wires lead to which corner, as well as which colour denote the polarity for each pair. You’ll find that the wires will adhere to some logical grouping on the loom. More on this in Part 2. One additional wire that needs to be run is from the subwoofer amplifier to the boot.
Step 8: Completing the amplifier wiring
If you’ve successfully completed running all the wires you can now connect everything up to the amplifiers and secure them into position. I also take this opportunity to set some basic input sensitivity level and crossover settings in readiness for finer tuning once the system is complete. This way when you initially power the system you won’t blow anything up or have strange crossover settings that may confuse you. Each amplifier should be connected in this order; earth, power, trigger, speaker wires, RCAs. Set the channel on the 4-channel amplifier to high pass on the crossover and set the frequency to 100Hz. Similarly, set the low pass filter on the subwoofer amplifier to 100Hz. Set all input sensitivity levels (gains) to one third, and leave all Bass EQ or other tone adjustments at zero for now. Since the main fuse at the engine bay is still disconnected the amplifiers are now ready so you can move onto the next stage of the installation.