FAQ - come out of frozenaudio.co.uk - 1st Dec 2003 8:04pm
What's the best way to spend my money?
The biggest improvement you can make to a standard head unit and speaker system is adding a subwoofer. This could be a pre-built item that has its own amplifier included, and takes the audio signal from the head unit's speaker outputs. These are known as active subwoofers and come in a variety of styles and sizes to suit just about anyone. Subwoofers are important in a car because of the large amount of background or road noise in the lower bass frequencies.
Why should I bother with an additional amplifier when my head unit is rated at 4 x 50W?
The way that amplifiers are rated can vary from one manufacturer to another, so it's impossible to directly compare watts unless you know that they were both measured in exactly the same way. Head units are usually measured as peak power or maximum output, whereas stand-alone amplifiers are usually measured in a far more meaningful RMS output into 4 ohms and a fixed level of distortion. As an example, a specific head unit with a 45W maximum output is also rated at only 17W per channel into 4 ohms with 0.8 per cent distortion.
How do I get more bass out of my system?
A quick answer to this one is adding more or bigger speakers. Generating bass is all about moving large volumes of air. Think of a speaker like a car's engine. The bigger the engine the more power it produces. To move more air you need to have a piston or speaker cone that has more area. To make the cone move back and forth even more means increasing the power supplied to it, but any speaker can only be pushed so far before it distorts or gets damaged.
Can I add a sub without extra amps or wires in the car?
Yes. There are some head units on the market that can be configured to run a subwoofer off their rear channels using a built-in crossover. Admittedly you are restricted by the power output, but it will get you started when building a system and gives the option of adding an amplifier later.
Can I fit a regular head unit in place of the weird-shaped old one?
In all but a very small number of cases, you can remove the standard unit and install specially designed fascia adaptors that surround a standard DIN-shaped model and make it fit in with the car's dash. You can get these adaptors for a whole host of vehicles from specialist car audio retailers and places like Halfords. You can also get adaptor harnesses to fit in between the original wiring loom and the new head unit, so that you don't have to cut into the standard loom. Some manufacturers even make aftermarket units that link in with dashboard remote displays.
If I am going to upgrade my speakers, should I start with the front or rear pairs?
It is often easier to change the rear speakers because of access, especially if you are trying to fit larger units to improve bass response. But just about all of the positional information or stereo image is derived from the front speakers, and it is this stereo image that helps to achieve a sense of realism in the sound. We'd recommend upgrading the front speakers before the rears and keep the head unit faded towards the front, with the rear channels only loud enough to give an ambient feeling.
Do I need speakers with a separate tweeter to get good sound?
Although component speaker systems with separate tweeters can give greater flexibility for installation, you can still buy decent coaxial speakers that have the tweeter mounted in front of the bass cone. These are also available with high-spec crossovers and can be driven by multi-channel amps. The build quality can be just as good as component systems, but all the drivers are fitted to the one chassis. You only really need the individual drivers where the installation position requires it, such as when the main driver is really low in the door.
The biggest improvement you can make to a standard head unit and speaker system is adding a subwoofer. This could be a pre-built item that has its own amplifier included, and takes the audio signal from the head unit's speaker outputs. These are known as active subwoofers and come in a variety of styles and sizes to suit just about anyone. Subwoofers are important in a car because of the large amount of background or road noise in the lower bass frequencies.
Why should I bother with an additional amplifier when my head unit is rated at 4 x 50W?
The way that amplifiers are rated can vary from one manufacturer to another, so it's impossible to directly compare watts unless you know that they were both measured in exactly the same way. Head units are usually measured as peak power or maximum output, whereas stand-alone amplifiers are usually measured in a far more meaningful RMS output into 4 ohms and a fixed level of distortion. As an example, a specific head unit with a 45W maximum output is also rated at only 17W per channel into 4 ohms with 0.8 per cent distortion.
How do I get more bass out of my system?
A quick answer to this one is adding more or bigger speakers. Generating bass is all about moving large volumes of air. Think of a speaker like a car's engine. The bigger the engine the more power it produces. To move more air you need to have a piston or speaker cone that has more area. To make the cone move back and forth even more means increasing the power supplied to it, but any speaker can only be pushed so far before it distorts or gets damaged.
Can I add a sub without extra amps or wires in the car?
Yes. There are some head units on the market that can be configured to run a subwoofer off their rear channels using a built-in crossover. Admittedly you are restricted by the power output, but it will get you started when building a system and gives the option of adding an amplifier later.
Can I fit a regular head unit in place of the weird-shaped old one?
In all but a very small number of cases, you can remove the standard unit and install specially designed fascia adaptors that surround a standard DIN-shaped model and make it fit in with the car's dash. You can get these adaptors for a whole host of vehicles from specialist car audio retailers and places like Halfords. You can also get adaptor harnesses to fit in between the original wiring loom and the new head unit, so that you don't have to cut into the standard loom. Some manufacturers even make aftermarket units that link in with dashboard remote displays.
If I am going to upgrade my speakers, should I start with the front or rear pairs?
It is often easier to change the rear speakers because of access, especially if you are trying to fit larger units to improve bass response. But just about all of the positional information or stereo image is derived from the front speakers, and it is this stereo image that helps to achieve a sense of realism in the sound. We'd recommend upgrading the front speakers before the rears and keep the head unit faded towards the front, with the rear channels only loud enough to give an ambient feeling.
Do I need speakers with a separate tweeter to get good sound?
Although component speaker systems with separate tweeters can give greater flexibility for installation, you can still buy decent coaxial speakers that have the tweeter mounted in front of the bass cone. These are also available with high-spec crossovers and can be driven by multi-channel amps. The build quality can be just as good as component systems, but all the drivers are fitted to the one chassis. You only really need the individual drivers where the installation position requires it, such as when the main driver is really low in the door.