Most Important Part of a Loud System

In my opinion, the correct enclosure is vital in getting the most out of your system. This is because the enclosure determines how your sub will react with the given airspace, tuning, and power. For example, a sub in a sealed enclosure will sound very different than one in a ported enclosure. Ported boxes are easy to identify because of the port opening.

A combination of port area (length x height) and port length work together to create the tuning frequency. The tuning frequency is denoted by hertz (hz), usually in the 20-70hz range when speaking of sub frequencies. Sub frequencies are also why subwoofers are called "subwoofers" and not simply "woofers" which refer to midrange frequencies. A combination of size and tuning determines the output of a system more than the power or subwoofer itself. You could have a high end subwoofer like a DD 9515, but in the incorrect box, it could be outdone by a lower end sub in an optimized box.

The key to making the best box possible is simple: test, test, test. There is no one best design because every car is different and will react differently with different boxes. Through lots of testing, I found that my car likes large boxes and a 40hz tuning. I've gone up against many people with more than twice the cone area (double the amount of subs) and have come out on top, even though I've got half the cone area in a very restricted sedan rather than the open cabin of an SUV. During these competitions, your score is measured in decibels at your highest frequency.

Therefore, it is extremely important to tune your box to reflect your highest outputting frequency. Right now, my box is tuned at 40hz and it also happens to hit its peak output at 40hz. That may or may not be the case for anybody else because as I said before, every car is different. Also, don't forget to take your subwoofer into consideration. Most of the time, you will usually peak a few hz above tuning. E.g. a tuning of 32hz may result in a peak of 40hz, depending on the car of course. In essence, tuning at a certain frequency allows you to control your output and determine what note you want to play the loudest, which is important when taking your car into consideration. Hatchbacks generally hit their highest score at higher frequencies (50-70hz) and SUVs generally hit their highest score at a lower note (40-50hz), while my sedan likes lower notes in the 40hz range the best.

Once you figure out what note your car likes, you can then start optimizing your box by making some small changes. Generally, slightly larger boxes with lower tunings perform best for cars that like lower notes. Slightly smaller boxes with higher tunings tend to complement cars that like higher tunings. For music and daily driving, tunings between 30-40hz are generally accepted as a fair tradeoff between sound quality and loudness.