In Car Entertainment System - Part I

In-Car-Entertainment, also called as ICE has very humble beginnings from back in 1930 when the 1st car radio was launched called Motorola 5T71, and today it has flourished into a mutli-billion dollar industry. ICE is a vital part of our daily lives, I doubt one can imagine traveling somewhere without music!! These days the car manufacturers have realized this, and now even the entry level cars come with factory mounted music systems. Though these may be good enough for a general user, many audiophiles want more...and boy do they have options!

So to elaborate more, here we have a small guide. And we start with the basic components required for a good ICE system.

Head Units/Receivers

The head unit, also called as a receiver, is the part of the car stereo that you interact with most. So it is important to get one that ‘feels’ good to you and something you’d like to look at every day. Since many models in the same price range are similar in features and sound quality, usability is often the deciding factor between models. The most common features on a head-unit today would be playback of a disc with support for MP3, WMA, AAC and Audio CD formats. In addition there is the standard AM/FM tuner and some units now sport an Aux-In and a USB port which allows you to plug in a pen-drive. Most receivers today support iPod connectivity although full-iPod control through the USB is something that not all manufacturers have in the market at the moment.

2 DIN Head Unit

When you’re looking at a receiver also consider whether it has Pre-amp outputs. These are must for any serious upgrades later on and are quite desirable in the head unit. These outputs allow you to run an amplifier directly and this is the cleanest signal output from a receiver. If your vehicle has a 2DIN slot you can go for double-DIN sized system. This widens your options since you can get a full-touch-screen based system with an in-dash DVD, and for those who want navigation this is a definite plus. With a large display you can install a reverse-camera for your car and have the camera image on your system display.

Manufacturers often use terms like ‘music power’ or ‘peak power’ which have little real meaning because there is no standard definition of those terms. If the power is quoted in ‘RMS’ terms then it is usually accurate. However, there is still one other place of misconception. Often manufacturers will quote power as ‘30watts x 4 RMS’. What they are implying here is that all 4 channels can produce 30watts RMS at the same time as a total and not per channel.

Amplifiers

To arrive at clean playing sound through the speakers your amplifier has to be up to the task. As explained before each receiver does have a built in amplifier but in order to get clean and powerful sound a dedicated amplifier is the right thing to do. Amplifiers, head units and speakers have to be matched well, so it is best to leave it to a professional installer if you’re still experimenting, since it can prove to an expensive mistake. Most installers in a mid-to-high end system will use a four channel amp to power your components inside of the car and a dedicated mono-block amplifier to run the sub-woofer. Do look at the construction and "feel" of the amp as well to help make your decision and you can always request for a demo on a vehicle with a similar setup to what you’d like to run to understand the difference an amp will make.

Speakers

Co-axial 6x9 speakers

The speakers are very important too, an awesome head unit and amp pair will be utter waste until nice quality speakers aren’t installed! A speaker called a tweeter reproduces high frequencies generally above 2 kHz. Tweeters are small and lightweight so they can respond quickly. Very little power is required for powering tweeters because they are very efficient.

However, the most common upgrade from the factory speakers are to a pair of Coaxial speakers which have the woofer and tweeter packaged in one unit. An improvement over the co-axial speaker can be seen in almost all cars with speaker upgrades. It is the ubiquitous ‘oval’ or 6x9 composite-speakers which has a mid-bass woofer, a mid range and a tweeter. This is a fair compromise without having to invest in separate components and unless you’re a true audiophile, you’ll be more than satisfied with the clarity and punch most of these speakers have.

Sub-woofers & Enclosures

Woofers are typically large and are sized anywhere from 8” to 18”, they are exact opposite of tweeters because they usually require large amounts of power to really move air. Woofers are meant to produce sound at frequencies below 250 Hz and often just below 100 Hz as in the case of sub-woofers.

The oldest and most popular type is a sealed enclosure. This method simply has the woofer firing into the car and the back wave is suppressed inside the box. This method usually produces tight accurate bass but is not as efficient. Also this method typically requires a large box to work well. Finally because of the lower efficiency of this design more powerful amps and woofers are needed to play loudly.

10" Tube Sub-Woofer

For people with limited boot space there’s always the bazooka tube sub-woofer enclosure which can utilize a smaller woofer and yet produce twice the amount of ‘loud boom’ thanks to the tube-bazooka design. This works well in hatchbacks or small sedans where space is at a premium. Another sensible option to get some punch into a small and basic install (which is just a receiver and four speakers) is to add an active sub-woofer. Essentially this is just a sub-woofer in an enclosure with its own dedicated built-in amplifier. This works well on the cost front with an active sub-woofer costing a tad less than if you’d add all the components separately. There’s also less wiring to deal with and it makes for a neater install. Several manufacturers in India have good quality active sub-woofers and if you get a slim packaged sub, you could even fit it under a seat.

 

Crossovers

An electronic crossover takes a full range signal and divides it into different frequency ranges. The most common types are 2-way or 3-way. A 2-way crossover divides the frequency range in half at some cut off frequency. All signals below the cut off frequency are routed to a low pass pre-amp output and the rest are sent to a high pass output. Usually these are just simple high pass or low pass units. You connect a high pass crossover to a speaker to block bass to that speaker. Some people call these “bass blockers”. You use a low pass crossover with a woofer so it only plays "lows." Typically component speakers (Coaxial speakers) which will consist of a mid range driver and a tweeter will come with a crossover which will split the sound and deliver quality sound that each individual speaker.

Sound processors / Equalizers

Equalizers give you the capability to fine tune your system. It is virtually impossible to get speakers to reproduce sound perfectly, and in a multiple speaker system things are even more complex because the different drivers interact with each other. With an equalizer you can boost or cut certain frequency ranges to tailor the overall sound to whatever you desire.

For real audiophiles, a lot of manufacturers have a separate EQ module with its own screen which allows you to fine tune the sound over and above what you’d be able to do with just your receiver. The number of bands in an equalizer tells you how fine an adjustment you can make. You can get a 10 band equalizer which breaks up the audio range into 10 parts, real audiophiles will love a 30 band EQ module, but be warned – these should only be considered if you’re a true connoisseur.

So much for the basic idea on the various elements of ICE systems, we hope that whatever has been mentioned helps you understand your system in much better way.

Coming up this week more on buying and setup, tuning, brands etc., so stay tuned...

- Grease Monkey Blog Team