The process of shopping for car audio amplifiers can be one of confusion and frustration. The uninformed will hear lots of big numbers and strange terms; even the informed can find themselves occasionally bewildered by the range of options available.
To help both types of consumers, we humbly offer some helpful hints.
It’s not necessarily wrong to look for big numbers with regards to output for a car audio amplifier. However, many brands try to hide the real power of the amplifier behind big claims, so you’ll always want to look for the RMS power rating. This is the continuous power rating, showing what you can really expect wattage wise from the amp.
Know Your Power
You can take the specs for an amplifier and check to make sure it really does put out what it claims it does with a simple formula: P=vce, where P is the total power output, v is the voltage of your car battery, c is the current draw for the amp, and e is the efficiency constant. If you plug in those numbers and the result is 5 percent less than what’s advertised or greater, pass on it.
Count Your Channels
Each speaker is a channel, and that includes the subwoofer. If you’ve got four speakers and a sub, don’t get a monoblock (one-channel) amp. Amplifiers for cars should, ideally, have the same number of channels as there are speakers. You can run multiple subwoofers off a mono block amp, since they run on the same frequency setting, but if looking for one amplifier to drive multiple size speakers, either a four or five channel amp is needed, or multiple amplifiers.
Make Sure You’ve Got Spare Power
Amps create a power budget for the speakers. Make sure that each speaker has a surplus. Underpowered speakers are far more susceptible to damage than overpowered speakers, due to the heat created by working a speaker at less wattage than needed.
Mount It Right
When having a car amplifier installation professionally done, think about where you want the amplifier placed. Ideally, you want to keep it as close to the battery as possible, to shorten the amount of wiring needed to power it. Installing an amp under a seat is normally ok, but can cause an amp to run hotter than normal, so sometimes the trunk is the only option. Just remember, the farther the amp from the battery, the bigger gauge wire you should use for best current conduction. Many of today’s newer vehicles place the battery in the back, making the connection a shorter distance and allowing better power flow.
Add Extra Power Sources
Car stereo amplifiers, along with other components, can be a major drain on a car’s battery. If you’re driving down the road with thumping bass going and the headlights are flickering in time with the beats, there’s too much power going out. Consider a secondary battery or capacitor, and also upgrading your existing wiring with the “Big three” upgrade.
The Right Wires
The best car amplifier should have the best wiring possible to ensure the highest possible performance. Look for Oxygen Free Copper (OFC) wires as opposed to Copper Clad Aluminum (CCA). OFC types conduct electricity far better, giving you the wattage you bought, and also doesn’t heat up the wire as much. Also, upgrading the Big-3 (The wire from the alternator to the battery, from the battery to the body ground, and the engine grounding wire to the battery.) will give your charging system much better performance.
It should go without saying, but always check the manufacturer’s warranty and make sure that the shop doing the installation is an authorized dealer for the amplifier and any other components you might be using. There are many “grey market” products out there, resulting in voided warranties thru the manufacturer when bought from a non-authorized dealer.