Shopping for a new car audio amplifier is tricky. There are thousands of amplifiers available from at least a hundred car audio companies. Picking the right amp for your system requires balancing an expectation of performance with the cost and features of the amp in question. In this issue of Bang for Your Buck, we are going to talk about car audio amplifier features that will make your audio system sound better and more enjoyable while maximizing your investment.
Amplifier Channels
Decades ago, you could choose from two- or four-channel amplifiers to power your audio system. Most people used a four-channel amp for the front and rear speakers and a high-power stereo amp bridged to drive a subwoofer or two. The rise in popularity of class D monoblock amplifiers in the ’90s replaced the big stereo amp on the subs with something more efficient, and often more powerful.
No matter how you divvy up the work, you are going to need multiple amplifier channels. Let’s look at two amplifier options for a starting point. A four-channel amplifier is extremely flexible. It can power your front and rear speakers, a set of components and a subwoofer or be dedicated to a set of components using active filters instead of passive networks. It’s rare that a high-quality four-channel amp can’t remain an important part of your system.
Another alternative for an amplifier is a five-channel model. In most cases, these amplifiers provide between 50 and 100 watts of power from the four main channels and 300 to 600 watts from the subwoofer channel. A significant advantage of these amplifiers is that they are housed in a single chassis. This design reduces the need for power and ground distribution blocks and simplifies installation.
Built-in Crossovers
When you are starting out on an audio system upgrade, you will want to take a close look at the crossovers built into the amplifier you are looking at. Assuming you go with a four channel amp, each channel pair will likely include crossovers that can be configured in a high- or low-pass mode. This crossover design makes the amp suitable to drive speakers or a subwoofer. If you plan on using the amp to drive a set of components in an active configuration (something that you should aspire to), then look for crossovers that can reach higher frequencies – in the 4 to 5 kHz range. If you are planning on using a digital signal processor to handle crossovers (another wise aspiration), then the crossover frequencies matter less.
Vehicle Integration Features
Upgrading a modern factory sound system can be tricky. In many applications, the source unit can’t be replaced. This means we need to connect to the radio or the amplifier. If you are planning on keeping your factory source unit in the system, then you will want to choose an amplifier that provides OEM integration features. First and foremost, the amplifier needs to be able to accept a speaker-level signal. Some amplifiers have dedicated connections for high-voltage signals. Other designs allow you to connect the factory speaker wires to the RCA inputs, then press a button to reduce the voltage to something that the amp can handle. A third popular option is amplifiers that include an RCA adapter that has circuitry built into it that reduces voltage.
The second feature you are going to want to look for is remote turn-on detection. Different companies have different names for this feature. In a nutshell, you want the amplifier to turn on when the factory stereo turns on. Amplifiers with automatic remote turn-on detection monitor the input connection for an audio signal or the presence of a DC voltage generated by BTL-type amplifiers in head units.
Remote Level Controls
If you are going to use the amp you have chosen to drive a subwoofer, then choose something that includes or has the provision for a remote level control. A remote level control is typically a small metal or plastic box with a knob sticking out of it. You can turn this knob up or down to increase or decrease the level of the subwoofer relative to the rest of the speakers in your car.
The best designs are attenuators. This means that at the maximum position, the amp behaves as though the knob isn’t connected. You can turn down the bass level by turning the knob counterclockwise. The reason this design is best lies in the process of how systems are tuned.
Ideally, try to avoid bass boost controls. If you want more bass, then you should want more of ALL your bass, not just those frequencies around 50Hz. Deep bass (below 30Hz) is a lot of fun!
Amplifier Power
Here’s another tricky subject that requires balancing a lot criteria. First, you can never have too much power available. With that said, depending on your speakers, you may have more power than you’ll ever be able to use. In almost every case, maximum amplifier power determines the size of the amplifier, and vice versa. A 1,500-watt subwoofer amplifier that will operate reliably on a hot summer day isn’t going to fit in the palm of your hand. If you are hoping to upgrade your audio system while keeping the equipment out of sight, then you will need to choose an amplifier that will fit under a seat or in a storage compartment.
In terms of speaker longevity, choose an amplifier that is rated at the same (real) power ratings as your speakers. If the system is set up properly, you shouldn’t have any reliability problems.
Amplifier Installation Accessories
The second-to-last step in choosing an amplifier for your vehicle is to choose the right installation accessories for it. No, we aren’t talking about chrome shrouds or lighting kits. Your choice of power wire can have a dramatic effect on the performance and reliability of your amplifier. It might sound like a sales pitch, but don’t be stingy with the wiring you choose. A $40 amp kit with 1,000-watts printed on the package may look like a deal, but do you think it will supply power to your amp the same way a $100 kit will?
Think of your power wire like the tires on your car. Inexpensive skinny tires work fine when you are cruising through town on the way to get the groceries. When it’s time to crank up the excitement, these tires fail to provide premium performance. A high-quality tire simply sticks to the road better, and in many cases, lasts longer. Power wire is the same.
Quality Installation and Configuration
Last and certainly not least is your choice of who will install your amplifier. Cars and trucks aren’t as simple as they used to be. Composite construction, aluminum, high-strength adhesives, computer data networks and BCM-controlled charging systems require that someone with extensive experience work on your vehicle. Assuming that your new car or truck is like every other vehicle they have worked on is a recipe for disaster.
A properly trained and qualified installation technician understands how to mount equipment safely and reliably. They understand the proper process to make electrical connections so that they are efficient and safe. Finally, they have a tried-and-true process that ensures every amplifier is configured to provide maximum performance and reliability. Choose whom you let work on your car very carefully.
Local Help With Car Audio Amplifier Features
When it comes time to upgrade your stereo system, drop into your local mobile enhancement retailer and ask about the latest car audio amplifier features. They will work with you to choose a solution that includes the features you want and provides the performance you desire.
