One of the best things you can do for your car audio system is to properly tune it. There are several variables to consider when doing this, and I am going to walk to through the most important ones so you will have a good understanding of how to get the most “bang” for the buck from you system.
Assuming you have an amplified system with one or more subwoofers, you can dial in your system to give you the best sound and have the durability you want from it. It starts at the head unit. You want a head unit with a good, strong output signal, between 4 and 5 volts on its pre-outs. Audiophiles tell us that 2-3 volts of good clean signal is good too, but that will require a little more amplifier power to get the decibels we’re looking for. You also want a head unit with an adjustable subwoofer level. Start by tuning the stereo without the subs on. Add your bass and treble until you get the desired sound with minimal distortion at the loudest volume setting you will listen to it at. This is generally about 2/3 max volume.
Once you are happy with the low/mid/high sound from the multi-range speakers, we can add in the subs. If applicable, tune the sub outputs to about 2/3 maximum, and head to the amp. Start at the amp and adjust the frequency and the level to minimum, and turn the volume up to the the same loudest point we were working with earlier. Pull your frequency to about half way, and slowly adjust the power level upwards. If you hit the zone you want, stay there. Keep in mind, this is only a safe adjusting technique with a speaker system that matches the power output of the amplifier. If you want more from your system, incrementally adjust the frequency down slightly with the increases in power level.
Your goal is to get a loud, clear bass from the subs that DOES NOT CLIP OUT under the loudest conditions you anticipate. If the amp clips out, then adjust the power level lower until it is back in the safe zone. Once the system is set where you want it, don’t mess with it. Leave the levels on the head unit and the amp alone. The mistake I see with blown speakers and amps is trying to show them off with all the levels maxed out. This produces a lot of power at a high distortion level, which is damaging to the speakers and the amplifier. If you want a louder sound than what you have by tuning your system this way, it may be time to upgrade.
Keep these guidelines in mind when configuring your systems, and you should be able to build a car stereo system that will sound great and have great durability. Good Luck and stay TUNED!