Mobile Entertainment System - Bumpin And Thumpin - Audio Video Special

  |   This F-150 by Prestige Customs & Auto Sound looks a lot like the other awe-inspiring trucks we splash across the pages of Truckin', but custom jams round out this ride. Typically, when you get a basic upgrade of your factory sound system, you get what's called a deck-and-two or deck-and-four. A deck-and-who? This means that you are replacing the factory head unit and two or four speakers with aftermarket models that fit in the factory locations. For most people, that's good enough, but chances are, you are not like most people. You spend time and money so your truck looks good, and you probably want to make sure it sounds good, too. Regardless of the level of your commitment to this aspect of the automotive aftermarket, it pays to educate yourself before diving into the mobile electronics rabbit hole. Read on for tips on how car audio works and what to look for before you buy. A typical mobile entertainment system is made of the following components: a head unit, sound processor, amplifier, speakers, subwoofer, and wiring. Video systems often plug into the audio system at the head unit, and include LCD monitors, a DVD or video cassette player (VCP), perhaps a switcher or similar component, maybe headphones, and even a video game console. Let's look at some of these components in greater detail. Head Unit
This is the radio or CD player in your dash. There is usually only one, and it acts as the interface between you and your entertainment system. The head unit connects to sound processors or external amplifiers via low-gauge RCA outputs. Wondering which model is the best for you? Don't sweat it, because most aftermarket head units in the same price range are just as good as the others when it comes to quality and basic functionality. This is especially true for head units ranging in price up to $250. They all have AM/FM, station presets, some degree of sound processing (bass boost, for example), cool cosmetics, or even graphics that come to life on a small display. Most play CDs, MP3s, or MiniDiscs, with a few dinosaurs still offering cassette playback, or a combination of these. These days, however, it is the addition of newer and more esoteric technologies that differentiate the mid- to high-end head units. What was once a simple radio receiver becomes a control center for high-tech add-ons such as navigation, DVD or VCP, TV tuners, CD changers, or MP3 storage units, and may not even have an integrated radio or CD/cassette player. Satellite radio services XM Satellite and Sirius provides cable TV-esque niche radio programming that is broadcast nationwide for the cost of a satellite-ready head unit, a tuner, antenna, and a monthly subscription rate of around $13. Sound Processors
Sound processors electronically improve the source signal from your head unit. Most head units actually have some form of sound processing incorporated into them, such as bass boost or an equalizer. A crossover is another common sound processor, and is integral to the function of speaker systems (more on crossovers later). Car makers don't give a lot of thought to factory speaker locations, which is why, from the driver's perspective, music from a stock system might wallow in the footwells, and passengers in the back seat will hear nothing but the speakers in the rear deck behind their heads. Surround-sound processors can mitigate these effects by lifting the music to about head level and making it more difficult to determine if the music is coming from the front or rear speakers. Amplifier
This is the workhorse of audio performance. An amplifier gives your speakers a stronger, cleaner signal to work with, allowing your speakers to push harder with less sound distortion. Many head units will have an internal amplifier that moderately boosts the signal, which might be good enough, depending on your needs. But, for those who want better overall sound quality, and perhaps more importantly, want enough power for thumping bass, get a stand-alone amp or two. You won't be sorry. Amplifiers are marketed by output in watts, number of channels, and impedance. Watts measure the power output of the amplifier. Since the strength of the signal will fluctuate, RMS (Root Mean Square) is used as a measure of how much continuous wattage an amplifier will deliver, while the peak rating tells you the absolute maximum it can crank out. The number of channels tells you how many speakers or subwoofers the amplifier can drive, and impedance (in ohms) measures the resistance of the amplifier or any circuit to the flow of electric current. For example, the 800-watt Rockford Fosgate Punch 801S has a rating of 200 watts x 2 at 4 ohms. This means it has two channels and delivers 200 watts per channel when there is an impedance of 4 ohms. Lowering the impedance to 2 ohms allows that same amplifier to provide 400 watts per channel (400Wx2), or it can be bridged to power a subwoofer at 800 watts over 1 channel at 4 ohms (800Wx1). Beware flea market specials that try to lure you with a ridiculous rating like 1,500 watts per channel for only $5. If you're not sure if an amplifier will live up to such an uber-rating, check the fuse. An amplifier needs a 30-ampere fuse for every 100 watts of performance. Amperes, also known as amps, measure the amount of electricity flowing through a circuit. A 200-watt amplifier that works on a 30-ampere fuse is really wired like a 100-watt amplifier. Another 200-watt amplifier that pops a 30-ampere fuse will never live up to its full potential. Either way, both of these amplifiers are substandard. Speakers
Most come in two styles. First, you have coaxials, which consist of a single speaker body with a tweeter placed over a midrange or woofer cone. Their cousins, triaxials, have a tweeter and midrange mounted over a woofer. Secondly, component speakers separate the midrange and tweeter, allowing an installer to place each component in different locations in your vehicle to better fit your vehicle's acoustic environment. A tweeter operates in the higher frequencies of 20 kilohertz (kHz) to 6kHz. A midrange speaker will generate sounds in the 6kHz to 500Hz range, and a woofer works from 500Hz to 100Hz. Crossovers separate the signal coming from the head unit or amplifier, and send the high-frequency signals to the tweeter, mid-frequency signals to the midrange, and low frequency signals to the woofer. This prevents distortion caused by a midrange speaker trying to play sounds best handled by a tweeter. Another variety of speaker has niche applications in a vehicle: horn-loaded compression drivers. They look like long, skinny megaphones, and sound like brassy tweeters. Speakers and subwoofers are often given a rating in watts. This tells you how strong a signal the speaker can take from an amplifier. Don't drive a 100-watt speaker with an amplifier that pumps 400 watts per channel or you'll get sound distortion and probably damage the speaker's cone. Some manufacturers bolster their product ratings by advertising the peak wattage, but don't be fooled. A speaker might be able to take 100-watt spikes from time to time, but will be better suited for continuous use at a lower wattage. Subwoofer
This is the speaker that goes boom. A subwoofer generates sound at a frequency of about 100Hz to 20Hz. It needs an enclosure, otherwise known as a box, to achieve the best performance. Some might be sold already built into an enclosure that looks like a box (such as the MTX MagnaForm),or might resemble a cylinder (such as the Bazooka Bass Tube). Most subwoofers,however, are purchased separately from an enclosure that needs to be custom-fitted to the subwoofer. The design of the enclosure depends on the specific frequency range the subwoofer needs to generate, where the subwoofer has to fit in the vehicle, and other factors. Enclosure types include sealed, vented or ported, band pass, dual reflex, and isobaric (which is not an enclosure so much as a way to mount the sub in a vehicle). Don't buy into the idea that you need a bigger subwoofer for big bass. Size does matter, but it's only half of the equation. Much of the performance is in the subwoofer's enclosure. Multimedia
It used to be that if passengers wanted to keep themselves occupied on a long road trip, they would stare out the car window and count the cows or risk car sickness by reading a book. And then there is that old standby - sleeping. Nowadays, however, video is becoming a mainstay of mobile entertainment. Multimedia systems will usually share some components with the sound system in a vehicle in the same way the TV in a home theater system is plugged into the stereo. A media player, such as a DVD or VCP, or a TV tuner and antenna feed a movie or broadcast into the head unit - if it has DVD, VCP, or TV tuner controls - which will operate both the audio and video in the vehicle. From there, the audio signal is routed through the sound system while video is shown on liquid crystal displays (LCDs). An A/V switcher might give you more flexibility when you have multiple media players feeding into multiple monitors, allowing junior sitting in back to watch SpongeBob SquarePants, while The Matrix plays up front. You can buy prefabricated multimedia systems that include a VCP, monitor, and controls, and that bolt into the vehicle's ceiling or replace the center console. Or, you can have monitors custom-fitted into your headrests, visors, and elsewhere. The considerations for choosing a monitor are similar to those of a laptop monitor, with the viewing angle at the top of the list. TFT LCDs offer the best viewing angle, but cost more. If possible, go large and get a 7-inch monitor. Wiring & Power
Wires are mobile entertainment's nervous system, and are just as differentiated as our own, particularly when it comes to the diameter, or gauge, of a wire or cable. Power and wire length dictate what gauge of wire a certain application requires. The wire connecting the battery to a head unit or amplifier carries a lot of current, so it is thick, measuring perhaps 1/0 and 8 gauge. Speaker wire, on the other hand, doesn't carry as much power, so it is thinner, maybe 12 or 16 gauge (the higher the gauge, the thinner the wire) Electronic systems generate a lot of electromagnetic interference. Wires, such as antennas, can pick up this interference, which will translate as unwanted noise. Various wiring designs shield the wires from such interference. The most common type of wire, coaxial cable, is one small-gauge wire jacketed by a braided cable, both of which are wrapped in a plastic jacket. Twisted-pair cables take two small-gauge cables and twist them around each other so the noise in one cancels the same noise in the other. While both work fine for most situations, twisted-pair is usually the better choice. For the everyday installation, and even most custom jobs, the automobile battery under your hood will work just fine. Should you decide to spend a lot of time at car or auto-sound competitions with your engine off and sound system blasting away, you might want to get a second battery to run the entertainment system so you can still drive off the lot at the end of the day. For systems that seriously tax the vehicle's charging system, a more capable alternator might be in order as well. Another useful power component is the capacitor. It stores an electrical charge and, when the demand is greatest from an amplifier, rapidly discharges power into the entertainment system and recharges again with very little loss of voltage. This keeps the system running smoothly during peak output. Capacitors are rated in farads, with most being 1 farad. A Word on FM Modulators
These allow a media player changer in a trunk or truck bed to connect without wires to a head unit. They are useful when laying wire is not an option or when you can't plug your portable MP3 or CD player into your head unit, but there is a drawback: The signal transmitted by radio is not as strong as that transmitted via cable or wiring. Installer
Last, but certainly not least, is the technician who installs all of this equipment into your vehicle. An installer who really knows their stuff will be able to tune the sound system to fit a vehicle amazingly well. We've sat in the front seat of a BMW with an aftermarket sound system that gave the impression that the band playing the music stood on the hood of the car with the vocalist closest to us, the drummer furthest away, and the guitarists somewhere in between. This was done without a surround-sound processor's electronic wizardry. Chances are, if you have spent years becoming a shade-tree mechanic extraordinaire in regard to suspension or engine mods, you might not have had enough time left over to become a mobile electronics expert. If that's the case, go to a good local mobile electronics dealer. Ask if the shop's installers are MECP certified (the mobile electronics equivalent of ASE certification). Find out how long they have been in the business, and ask to look at their portfolio of recent installations. Many installers started as hobbyists, just like you, and were eventually hired onto an installation staff. The right people love this stuff, and will work into the wee hours to get a job done. Good, Better, Best
Do you feel ready to toss that factory entertainment system into the junk heap and invest in an aftermarket upgrade? Well, prepare to spend. A new radio can cost as little as $150, and a kick-ass sound system with some video can cost $5,000 and up, up, up. Major custom jobs often entail cutting holes for custom speaker and video locations, replacing seats, reupholstering interiors, mounting new wheels, building new center consoles, painting custom graphics on the car body, you name it. Projects like this can cost $10,000, $20,000, even $30,000. Thankfully, you don't have to pay $10,000 to get a great system for your truck unless you want to join the show circuit. The owner of the Ford F-150 we are about to describe did just that, although it wasn't his initial intention when he brought his truck to Prestige Customs & Auto Sound in Metairie, Louisiana, for a simple deck-and-two. But, he got so excited as the project progressed that he upgraded the truck to show car status. Here is the roadmap to a vehicle that began with an entry-level system, moved up to a killer system in a daily driver, to one that ends up in magazines such as ours Good
The stock head unit was replaced with a JVC unit (dual RCA out, remote control, CD, detachable face, in addition to the usual features). Replaced the stock speakers with Kicker 5x7-inch component speakers. Two 8-inch subwoofers were added in a ported box behind the seats, as well as the following Memphis amplifiers: 16-MC300 150W x 2 for the speakers, 16-MC500D 250W x 1 for the subwoofers. Installed were flush-mounted tweeters in the bottom of the A-pillars. This is a very good sound system for about $1,200. Better
The stock seats were modified to make them bucket-like. The center console was remolded with fiberglass to accept a Pioneer head unit (which replaced the JVC unit), air conditioning controls, a PlayStation 2 console, and a Fahrenheit wide-screen LCD monitor. The color of the console was matched to the outside of the vehicle. These were nice additions for another $2,000. Best
The custom enclosure installed on the first visit was replaced with three 12-inch subwoofers in solobaric enclosures. The subwoofers fire into the cab through a hole cut in the bed. The amplifiers were upgraded and mounted in a custom amplifier rack in the bed, and they were colored to match the paintjob of the truck. Awesome graphics were added throughout. Tack on another $6,000 for this phase. Total cost for the whole project? You do the math, but they could have stopped at any of the three phases and still would have had a sound or video system that would have done the job right.