How to Choose a Car Stereo Amplifier

Adding an amplifier to your car stereo will improve the sound dramatically. Here's what you need to know to choose one that's right for you.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Amplifiers
• Measuring Tapes
• Paper And Pencils

At the Shop

1. Ask a salesperson or installer what power rating you should consider, based on your existing stereo, speakers and musical taste.

2. Select two or three amplifiers to compare.

3. Compare amplifiers' power ratings using the same parameters - ohms rating, voltage or frequency. (Most people in the industry use ohms rating as the standard of comparison, and set the standard at 4 ohms.)

4. Ask the salesperson to plug the possible amplifiers into a radio and speakers that are similar to the ones in your car.

5. Listen to the performance of each amplifier and select the one that sounds best to you.

6. Check the physical size of the amplifier to make sure it will fit where you plan to put it.

Before Shopping

7. Gather as much technical information about your car's current stereo and speakers as you can.

8. Determine where you intend to place the amplifier in your car.

9. Measure the area and write down the dimensions.

Tips & Warnings

• If your car radio doesn't have a low-level output, your amplifier will need a high-level input. This allows you to connect the speaker wires from the radio directly to the amplifier.
• Select a location where the amplifier will get plenty of air so it won't overheat.

on 6/30/2006 More important than the actual wattage of the amplifier is the quality of the signal. A speaker driven at half its rated power with a heavily distorted signal will burn faster than a speaker driven at slightly more than its rated power with a high-quality, clean signal.

on 11/22/2005 Try to get a Class D amp for your woofers, they're more efficient and deliver more power than the Class A or B amps!!

on 11/22/2005 I have two dual voice coil 12" subwoofers with 1" exclusion each. They handle 800 watts RMS each. I only have a 640 watt RMS amplifier to run both of them at 2 ohms each. You've got to make sure it's RMS power, not MAX power. Each subwoofer only gets 320 watts of power, but it sounds good and it's enough power to impress just about everyone I show them to. Avoid pusing your subwoofers to the max, because they will "max out." This makes a clipping sound, which ruins the richness of the bass. The speakers also burn out much much easier.

on 11/22/2005 Before going to the store to buy an amp, have someone that you know and you are sure that they know what they are talking about go with you before to show you everything. Your friend doesn't care if you buy a $600 amp or a $200 amp...but the salesman does. If you are buying the amp for subwoofers, make sure you know how many watts each speaker can take (usually on the back of the speaker). If each speaker can hold up to 1,000 watts each, the salesman will want you to buy the 2,000 watt amp or the 1,800 watt amp, when the 600 watt amp will do just fine. But always remember that just like having too much wattage can blow your speakers, not enough watts can do the same exact thing!

on 11/22/2005 The gain controls how much power gets fed to the speakers. Using it as a volume control will blow a speaker in a matter of seconds if adjusted improperly. Turn the volume on the head unit up to 3/4 and adjust the gain until you hear distortion, then lower the gain slightly. This will keep the amplifier and speakers from being destroyed.