In-Car Audio Buying Guide

Buyers' Guide to In-Car Audio Contents

• Getting the music in
• iPodding on-the-cheap
• Head of the class
• Your in-car audio options
• Getting the music out
• Amps
• Speakers
• The power behind the music
• Add it all up
• Watts that?
• What is Dolby and why do you need it?
• Tech terms you will come across

---------------------------------------------------------------------------------------

We've come a long way since the AM radio and the 8-track cartridge first let us take our entertainment on the road. These days automotive audiophiles have almost unlimited choice in custom sound equipment, from sweet-sounding stereos to "doof-doof" boxes that'll make your ears bleed. Here's how to make some sound decisions about your in-car audio system.

There are essentially two main areas that need to be considered in upgrading your sound system. The first is getting the music into the car - via radio, tape, CD, MP3 player or mini-disc unit, etc. The second is getting the music out of the car - via speakers, amplifiers (amps), subwoofers and so on. You can upgrade either of these areas alone, to some extent, but best results will be obtained by planning a co-ordinated approach.

Getting the music in

Most modern cars come with a basic (or "stock") sound system including an AM/FM stereo radio and single-disc in-dash CD player (these days CD players are pretty much standard, replacing the cassette players of the previous era). Some CD units now offer support for MP3, WMA and AAC. Most basic systems will have four speakers (two in front, two in back). Some mid-range (and many upper range) cars also come with a 6-12 disc CD changer (or "stacker").

While CD stackers used to be the ultimate in audio one-upmanship over your neighbour, the popularity of the Apple iPod hard-disk based portable music player has lifted the bar dramatically, offering thousands of songs at your fingertips - far more than even MP3 CD-compatible stackers can offer.

Customising your in-car sound system can range from the modest to the magnificent. The simple addition of an amp can lift your car's sound profile to a much more enjoyable level. But for some people the bigger and bolder the system, the better.

More upper range cars are now offering the option of iPod integration as an option, or even as standard equipment. These include BMW, Mini, Mercedes-Benz, Volvo with Honda, Volkswagen, Nissan, Audi and even Ferrari featuring the ubiquitous iPod in upcoming models.

The aftermarket is booming too. Several top car stereo accessory manufacturers now offer iPod integration for most cars, from iPod-ready head units to self-install options to professionally installed interfaces.

Alpine, Pioneer, Clarion, Kenwood and a growing list of others now offer integration accessories that make the iPod, Creative's Zen, and other portable MP3 players work like part of your sound system. This lets you use your head unit (main system control interface) for navigating and choosing songs, displaying all the information on the main unit interface. It is easier to use and therefore less distracting while you are driving, so it is safer than having to fiddle with the MP3 player itself. And the bonus is that these systems also charge your iPod, and other MP3 players, while you drive, so when you stop you simply pop the portable player in your pocket and you're charged up and ready to go.

iPodding on-the-cheap

Audio purists may blanch at the following, but if you want the convenience of instant iPod "integration" without the need for the modifications and expense of a factory-installed or sophisticated aftermarket unit, you can opt for one of the plug-in FM transmitter solutions which let you become your own personal "radio station", sending your tunes directly to your sound system via a neutral FM band.

The best of this genre usually combines an iPod caddy with an FM transmitter and plugs into your auxiliary power (cigarette lighter) socket, so it also charges your iPod while you drive (eg, the Griffin RoadTrip and the DLO Transpod).

While generally quite effective, totally transportable from car to car and relatively cheap (around $150-$180) the drawback of this system is that in heavily built-up areas it can sometimes be hard to find a clear "blank" spot on the FM band to tune into, and your sound quality may suffer.

Head of the class

iPods aside, the part of your sound system that you will deal with most is the head unit. This is your main interface to whatever you have hooked up to the system. It is from here that you switch between modes (radio, cassette, CD, minidisc, MP3 player etc), control volume, balance, fading and the general sound geometry of your system.

Head units these days come in an amazing variety of looks and configurations, often with dazzling animated front display units, some in full colour. Go to any car audio retailer or electronics store and you will usually find an extensive array of them to compare and choose from.

Some of them are real showstoppers, with an array of lights, buttons and display options that would stump a jet pilot. Others have a slightly more understated look. Most will have similar basic functionality but with head units you need to find the look that suits your car (and personality) as well as the features you need.

Be prepared to spend some time playing with the display units and comparing look, feel and functions with others. Most importantly, if you are mixing and matching the components of your whole system to get the exact sound capacity and features you need, you will have to make sure that the head unit and other components are all fully compatible and will work happily together once you have assembled the system in your car.

Your in-car audio options

Strange as it may seem, inside your car can be a far better listening environment than in your home, if your system is designed correctly. A typical car's defined space and fixed seating can provide a great listening environment that you can tune your system for. Space may be more limited than in the home, but you can still build your audio system to suit it.

A true audiophile who spends a lot of time commuting, for instance, will probably be drawn to the super high-quality DVD-Audio, the successor to the CD. DVD-Audio reproduces original studio or concert performances with bit-for-bit accuracy. It has multichannel capabilities for real surround sound, and also carries multimedia "extras" which can be accessed with the right equipment (eg, visual displays of lyrics, liner notes, artist photos and biographies).

For "people movers" which often have a couple (or more) children in the rear, a split system that incorporates a DVD player and/or a game console in the back (with headphones) will let you listen to your favourite audio while driving, without getting driven around the bend by endless repeats of The Wiggles, Barney, Hi-5 or game music and special effects noises. Or, for top quality audio the whole car can enjoy with the rich, full effect of surround sound, you might go with a system that incorporates Dolby Pro Logic II technology and a front center speaker.

Getting the music out

Getting the best sound out of your in-car audio system is more than just a matter of buying the best (or most expensive) components. It is a combination of choosing the right components and installing them correctly.

For example, you can have a powerful and expensive amplifier, but without enough electrical current to it the results will be very disappointing. Correct matching of components and proper installation is the largest contributing factor to the success of a system.

More is not necessarily better. Too many speakers can give your car volume, but not one cohesive sound. More components also mean a longer way for signal to travel and more risk of distortion.

For most cars, an ideal in-car audio system is based on a head unit with one or two amplifiers, one superb set of front speakers (which are responsible for the majority of the final result) and a small subwoofer.

Amps

Amplifiers provide the power, measured in Watts, to drive the speakers. Factory-installed head units have an amplifier built in, but only a relatively small one (often 10 watts per channel or less). Many aftermarket head units have at least twice that. The more power your amp delivers, the cleaner the sound at the speakers (as long as it doesn't exceed the capacity of the speakers). Serious audiophiles eschew the modest amps built into head units and go for powerful external amplifiers instead. They really can make a big difference to your in-car sound.

For the easiest (and cheapest) installation, look for a single amplifier to power all your speakers. This would be the number of channels listed on the amp (a single channel powers one speaker). And look for an amplifier that contains its own crossovers (filters). These circuits split the music frequencies so (for example) the highs go to the front speakers while the lows go the rear speakers and/or to the tweeters and woofers, for maximum power and sound clarity. If you add a subwoofer for beefy low-end bass, you'll usually need a separate amplifier just for that.

Depending on your application, the number of speaker-level and line-level outputs and inputs need to be considered. Make sure you have enough for the setup you are currently installing, while leaving room for at least one future upgrade.

Amps can generate a quite a bit of heat, which affects performance. Usually, metal fins are built into the amp to help dissipate heat, but location can also be an important factor. Some advanced systems even use liquid cooling to keep the temperature down.

Amps can be installed inside the car, but many get mounted in the boot (along with CD stackers etc). This, of course, requires running cables from the head unit in the dash. Note that amp position and placement can be affected by accessibility issues, heat, noise and interference.

Speakers

High-end audio systems include component speakers that consist of a matched tweeter, midrange and woofer set. These component pairs are available in two speaker and three speaker combinations, and include an audio crossover which limits the frequency range that each component speaker must handle. In addition a subwoofer(s) is provided for low frequency music information.

A tweeter produces high frequencies, from around 5000HZ to 22,000Hz (the latter being the upper limit of the human ear). Placement of tweeters is much more important than woofers and mid-range speakers, as high frequencies are more directional than the lower frequencies. This will affect the position and direction in which you face a tweeter to get the best results.

A mid-range speaker (sometimes known as a squawker) produces the middle frequency range, from about 300-5000Hz.

A woofer is the general term for a speaker which specialises in low-frequency sounds, typically from around 40 Hertz (Hz) up to several hundred Hz. Some modern woofers can reproduce sounds as low as 1Hz (the human ear detects a range of 20Hz to 20,000Hz). Some woofers produce frequencies up to around 1000-2000Hz and are usually called mid-woofers. These mid-woofers are usually the largest speakers in your sound system, apart from the subwoofer.

The subwoofer delivers the lowest bass notes in the music from the lowest frequencies audible, up to around 60-150Hz. They give the music its low-end "punch". In the Dolby Digital 5.1 format, the ".1" channel is dedicated solely to the subwoofer. Usually only one subwoofer is required for a system and typically, it is installed in the rear of a car (usually in the boot). Woofers, and in particular subwoofers, give you a sound you can actually feel. There is no mistaking the bone-shaking doof-doof thump of big bass woofers.

The power behind the music

A serious upgrade of your car's audio will put a drain on its electrical system, draining your car's battery faster than the alternator can charge it. If you're going to install high-power audio system components, you will need to upgrade the alternator and probably the car battery. If you want to amp your car up to power your next party, adding an extra battery (or, in extreme cases, banks of them) will let you party-on for long periods without running the engine.

Add it all up

It sounds like common sense, but whether you are going for a "kit" system from one particular manufacturer or whether you want to mix and match your head unit, amplifier, speakers and sub-woofer, along with other components, it is easy to get carried away with the looks and sounds and forget to double-check the specifications to make sure the figures all add up.

Doing your homework before forking out for your car audio components can save you a lot of hassle and help you make the sound decisions you need so you and your car can make sweet music together.

What is Dolby and why do you need it?

If you have bought any quality sound components in recent years you will have heard the term Dolby. Most in-car audio and other entertainment products now include Dolby technologies. Dolby technologies are generally held as the "gold standard" for high-quality audio and surround sound in cinema, home theatre systems, and even professional recording studios. But there is more than one type of Dolby sound standard. And despite Dolby having the lion's share of audio-buying awareness, there are other noteworthy companies with in-car audio, such as dts and Logic7. Let's look at them briefly:

Dolby Digital: This is the state-of-the-art 5.1-channel surround format - ie, five full-range channels (left, center, right, left surround, right surround) plus the "0.1" - a low-frequency (bass, or sub-woofer) effects channel. This technology is commonly found in cinemas, DVDs, digital television (HDTV and SDTV) and games. Dolby Digital technology in the car is often built into rear-seat entertainment systems featuring DVD-Video players.

Dolby Pro Logic II: Pro Logic II converts two-channel stereo into natural, richer surround sound and can be incorporated into car sound systems to enhance conventional stereo. Pro Logic II works with any high quality stereo source, including CD, FM radio, cassettes, XM or Sirius satellite radio, and MP3 files.

Dolby Headphone: This technology simulates, through any standard set of headphones, the effect of a 5.1-channel speaker system so convincingly that you tend to forget you're wearing them. In the car, Dolby Headphone technology gives rear-seat passengers the home theatre effect without disturbing the driver.

MLP Lossless: This is the core audio technology behind DVD-Audio, the highest-quality audio format. MLP Lossless technology enables studio master disc-quality audio to be encoded on an optical disc, with no loss in quality. It gives the listener a faithful audio replica of the original studio master, just as it was recorded in the studio. DVD-Audio offers sonic resolution that is 1000 times better than CD quality.

dts: This is an alternative to Dolby Digital and Pro Logic II. Though not as widespread, dts can be found on some DVD-Video players and DVD discs.

Logic 7: Another alternative to Dolby technologies, Logic 7 is found in several new vehicle models, but does not offer its technology to aftermarket products.

Your department store source to buy cheap used and new items online