- Ask a salesperson or installer what power rating you should consider, based on your existing stereo, speakers and musical taste.
- Select two or three amplifiers to compare.
- 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.)
- Ask the salesperson to plug the possible amplifiers into a radio and speakers that are similar to the ones in your car.
- Listen to the performance of each amplifier and select the one that sounds best to you.
- Check the physical size of the amplifier to make sure it will fit where you plan to put it.
- Gather as much technical information about your car’s current stereo and speakers as you can.
- Determine where you intend to place the amplifier in your car.
- Measure the area and write down the dimensions.
More Tips and FYI
- Choose an amplifier that’s stable down to 2 ohms. This will prove beneficial if you intend to add subwoofers to your system later.
If the amplifier and the radio can both accept two pairs of RCA cables, you’ll be able to use the radio’s fader control. If the amplifier or radio can take only one pair of RCA cables, the fader won’t function.
The amplifier should have gain (volume) controls for the front and rear channels.
Choose an amplifier that has built-in low-pass and high-pass crossovers.
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.