One of the most critical components in a high-quality vehicle entertainment system is your car audio amplifier. While the concept of increasing the power of an audio signal is simple, it can be somewhat complex to execute elegantly the process. Amplifier design is as much as science as it is an art form. In this article, we will look at everything you need to know to buy the right amplifier for your system.
How We Measure Car Audio Amplifiers
For more than 100 years, people have been using amplifiers to take a small audio signal and increase its power so it can move a speaker. We measure an amplifier’s capacity to do work in watts. Before the industry had a reference set of guidelines for measuring amplifier power, we would see outrageous claims from otherwise minuscule products. The Consumer Technology Association (formerly the Consumer Electronics Association) has worked with industry experts and manufacturers to produce a set of standards to allow the power produced by different brands, makes and models of amplifiers to be comparable. This standard is currently known as CEA-2006A. When you see the associated logo on a product, you can be confident that the power specifications are real and directly comparable.
Features Help Increase Performance
Modern car audio amplifiers are equipped with many different features. These can include crossovers, bass boost circuits, remote level controls and equalization. Crossovers allow your installer to limit the range of frequencies that the amp will reproduce. In the case of a subwoofer amplifier, we can send the entire audio spectrum to the amp. With a low-pass crossover set, only those frequencies below the crossover point will be amplified and sent to the speaker. A high-pass crossover does the opposite, sending only high-frequency information from the input to the output of the amp.
Limiting which frequencies pass through the amplifier allows the speakers to operate within the frequency range for which they were designed. You wouldn’t want bass information to be sent to your tweeters, nor would you want midrange and high-frequency information to be sent to your subwoofer. Almost every car audio amplifier includes crossovers.
Infrasonic or subsonic filters and bass boost controls are additional tuning options that can be used to help maximize the performance of a dedicated subwoofer amplifier. A remote level control – something also found on most subwoofer amplifiers is a volume control for the amp that can be mounted in the front of the vehicle. This control gives you the option of fine-tuning the amount of bass right at your fingertips.
Auditioning a Car Audio Amplifier
Quantifying the performance of a car audio amplifier can be very difficult. The speakers connected to the amplifier are an infinitely bigger contributing factor to how a system sounds. To properly audition an amp, you need to compare it to another using the same set of speakers. A display board in a car audio specialty retailer is a great way to do this. You will want to ensure that the volume level of all amplifiers is the same for the comparison to be valid.
How can the design of an amplifier affect the way it sounds? There are always exceptions, but for the most part, whether the amp is a Class AB or Class D design can have an effect on the high-frequency performance. Class AB amps are often more detailed in the highest of frequencies. Switch back and forth between amplifiers on a display and listen to the ring of a crash or ride cymbal, or that of a triangle. You want to hear clarity and detail.
At the opposite end of the spectrum, the impact and definition of lower frequency information can show off differences in the design of an amplifier’s power supply and the way the amp behaves when amplifying a complex signal. What you want to listen for is the perceived “speed” of the car audio amplifier. When a drummer hits the rim of a tom with his stick or the skin of the bass drum with the pedal, you want be startled. It should be very tight and controlled. The sound should be clear and natural.
One thing you don’t want to hear is warmth. While this goes against what many people perceive as good, warmth can be a sign of even-order harmonic distortion. The best amplifiers don’t change the sound; they just make the signal louder.
What’s Right For You?
When it comes to choosing an amplifier for your mobile entertainment system, the right amp for you is the one that fulfills your system requirements. A four-channel amplifier has always been a great starting point for system upgrades. They can be used to run four speakers and a subwoofer. If a dedicated subwoofer amp is added later on, that four-channel amp can do an even better job of powering those same four speakers. A lot of specialists like to use a four-channel amp to power a set of midrange tweeters and some form of electronic crossover to split up the audio signal between the two.
Amplifiers are available with one to eight channels at power levels from 35 watts per channel to almost 20,000 watts. Always make sure you have enough power for your system. If saving for another few weeks will let you purchase a more powerful amp instead of one that is “just enough,” it is well worth waiting.
The Latest And Greatest
In the past few years, many companies have introduced car audio amplifiers that include powerful DSP processors. These signal processors provide your installer with more control over system crossovers and add time-alignment and advanced equalization options. In the hands of an expert installer, this can add amazing accuracy and realism to a system. When tuned properly, they are the icing on the cake!
A Word About Installation
While car audio amplifiers seem like one of the easiest components to install in a vehicle, the challenge of sourcing a proper audio signal for that amp from a factory radio and dealing with varying current delivery challenges found in today’s automobiles can make proper installation difficult. Having an experienced technician at a car audio shop install and configure your amp is highly recommended. In many cases, manufacturers offer an extended warranty when their products are installed by an authorized dealer.
Visit your local car audio specialist retailer and bring along your favorite music. Listen to as many different amplifiers as you can, then choose the one that meets your system needs, your performance goals and your budget.
