I dropped it a while ago. I was saying the search thing, because it would have taken you less time to use the search function, than it would have been to ask about it.
Hz-Tuning : Used for ported/bandpass boxes. It is the amount of tuning the port has. I.E. I have a 2.16 cubic foot box, tuned to 36Hz. Higher tuning will have higher output. Lower tuning, will extend the 'low end' output. For sound quality, you'd most likely want to tune lower. For a combination of output, and sound quality, you'd tune to the mid-to-high 30's. Most companies that are known here, supply default tuning for ported boxes. You can change the tuning, depending on your preferences. If you don't find tuning suggestions, and you want 'optimal' tuning, there are several programs that are used in conjunction with the T/S (Theile/Small) parameters.
As for capacitors... They are worthless. Just a big bulky paper weight. They are 'suppose' to stiffen the voltage, so you don't have voltage drops while running a 'high demand' system, if your alternator can't supply the amperage needed quick enough. On a lot of cars, you can run 1000WRMS systems, on just stock electrical. If you're running a 'high demand' system, that is going to pull a lot of amperage from the electrical, you'd want to get a second BATTERY, or a H/O (High Output) alternator. Another thing about batteries, you can run a system with the car off, longer, without draining the battery, and exposing your equipment to low voltage, which will result in clipping, and can make a perfect component fail. I personally don't recommend running a stereo with high electrical demands, in a car while it is not running, unless you have the battery bank to back up the electrical demands. If you're wanting to add a second battery, just to be safe, I like the Optima Redtops, or the Kinetik HC600. Cheap batteries, and will do nothing but good.