Car stereo systems come in all shapes and sizes but have basically the same three components -- a radio, an amplifier and speakers. If you want to make your system sound better, then you need to start with the stereo amplifier. Let's look at how it works, what to look for and where to get one:
- How it works. The sound that you hear when you put on your car stereo systems starts with the head unit. This is what controls the radio frequency, CD, MP3 player or what have you, as well as equalization, balance, etc. The signal from this unit travels into the car audio amplifier, which boosts it and then sends it along to the speakers. This increase in the signal is what makes all the difference between a bad sound and a great sound. If your radio sounds like it's distorted and bad, don't blame the speakers -- your amp just isn't up to snuff. People are quick to blame bad audio on blown speakers, but a bad amp does more damage to audio quality and will actually be the cause of a blown speaker! If you turn the volume way up and your amp tries to overreach its limits, it produces something called total harmonic distortion in the signal. This will blow your speakers and hurt your ears. So more power will not hurt the speakers as much as lower power trying to reach a higher level will. Factory car radios usually have an amp attached to the back of the radio but aftermarket amps are located elsewhere in the vehicle (the trunk or under a seat) and attached by a cable.
- What to look for. The first thing to look for is power. Stereo amplifier power is measured by wattage using a math equation called Root Mean Square or RMS. The measurement is of how big the AC signal can get in the amp. The wattage is measured per channel, in most cases left and right channels for a total of two. Now, always look for total watts per channel. Some companies like to combine the wattage to make it look more powerful than it is. A 50 watt total is still just 25 watts per channel. Some companies go even further to try and deceive you by using a "peak" power rating. Most car amplifiers can generate more power than they list but when they do it is usually that bad power we discussed before, the harmonic distortion power.
Secondly, see if your vehicle has two-way speakers installed. If it does then you may want an amp with a crossover built into it. This basically makes sure the high frequencies go to the smaller speakers and the bulk of the power goes to the bigger speakers. If you have regular, stock car speakers, you probably do not need this - but if you ever upgrade speakers you'll be glad you have it. Ask your local car stereo installer for advice pertaining to your particular vehicle and its components. The key is look for something with a lot of power. You don't need anything crazy big, but more is usually better in this case. Some quality amplifier brands (in no particular order) are Blaupunkt, Rockford Fosgate, Kenwood, Alpine, Pioneer, Profile, MTX, Audiobahn, Infinity, JBL, Visonek and Sony. Look for these and you will be on the right path.
- Where to buy. You can get car amps online for good prices. Crutchfield is always a great place to find quality car sound systems and audio components. Amazon and eBay will have good deals, too, and you can always Google "car stereo amplifiers" to browse through a couple of hundred retailers. Big stores such as Best Buy carry amps, and they have qualified people to discuss and even install them if you'd like. The best place, however, is your local car stereo shop. These guys live and breathe this stuff. They will show you what you need and all of your options, all the while explaining the differences and nuances of the different products. I highly recommend you let them do the installing of any new amplifier also. This is what they do, and most do it very well. You can also easily stop in to visit them if you ever have problems or questions afterward.