Car stereo system capacitors, which give a boost to your car's battery, are also known as power capacitors or stiffening capacitors.
When heavy bass notes hit, your battery can lose voltage. Capacitors can stop this from happening.
In the same vein as bass control, lights may dim when heavy bass notes hit. Capacitors help the battery stay constant.
Capacitors charge off of the car's battery. They reuse this power when releasing energy to the amplifier. This saves energy output from your battery.
If you can connect your capacitors, you can make your output that much stronger and more steady. This helps your stereo's audio quality.
Your capacitors charge quickly upon installation. You'll want to exercise caution if you try to charge your capacitors before putting them into your car, because they could fry the stereo system.