These come in many shapes, sizes, and types including:

• Tweeters
• Midbass
• Coaxials (2-way)
• Triaxials (3-way)
• Round
• Oval
• 4x7's, 5x7's, 6x8's, 5.25's, 6.5's, etc.

So which one is right for you?
If your looking to just do a factory upgrade, not do any modification, or have a blown speaker and just want to replace it I'd recommend a set of decent coaxial/triaxial speakers. They'll play better than the factory door speakers, and you generally don't need an amp to bring out their full potential. Also as plus they're available in factory sizes so it's just a simple bolt in swap. If you don't know what your factory size is, get on crutchfield and use the outfit my vehicle tool they have, it'll tell you what size your speakers are.

Okay, so you don't want to do just a basic swap, your looking to amp up your system some?
I'd definitely recommend a set of component speakers. What are components? These consist of a tweeter, a midbass, and a crossover. These work by using the crossover to only send certain signals to each speaker. This helps cut down on distortion and allow the speaker to play more clearly because it won't send the speaker frequencies that it doesn't like to reproduce. However to get the full potential out of the speakers you need to power them with an amp, and deaden the doors. (More on this down lower)

So now your ready to add some low end to your vehicle? Subwoofers are great because they'll fill in the frequencies that door speakers can't reproduce without severe distortion. Or if you wish, they'll give you that ground shaking bass that'll wake the neighbors and make you do a hair trick. This area is a lot of personal preference, whether you want a simple sq (sound quality) setup, a decent daily driver system, or your going for numbers with a spl (sound pressure level) setup. Subs, like door speakers have many different configurations also including:

• Round, Square, Oblong, Etc.
• Single, Dual, or Quad Voice coils
• 8" all the way up to 21" (maybe even bigger)
• 1ohm, 2ohm, 3ohm, 6ohm, 8ohm, etc.

So what's right for you? If you want a sq setup I'd recommend going with one or two 8's or 10's sealed. They'll be able to pick up where your midbass leaves off, and still be able to hit most of those lower frequencies. A single 12 sealed could also work, but the main thing in a sq setup is you want all the sound to blend, so you don't want the bass to be overpowering the highs.

You want a decent daily driver where it's not overpowering but something you can still show off to your friends to make them think your cool? This is where it gets tricky. A decent set of 8's or ten's ported can definitely give your friends that wow factor, however you make sacrifices going ported (more on this later). Or a set of 12's sealed can give you a great daily driver system that would love to be shown off, or even a single 15.

So you just wanna pull numbers, demo your vehicle, or shatter your neighbors windows? First of all, definitely go ported. Now here is where size of the sub doesn't play as big of a difference. For the other setups, different size subs can have difficulties reproducing certain frequencies. But when you go ported, you tune your box to your subs optimal frequency (Generally around 32Hz). Don't forget to factor in cabin gain though, our trucks act as like a bigger box that your's is inside of when ported and it'll give you a more peaky response between the ~28 to ~50Hz area, which means it'll be even louder.

No matter which way you decide to go, you'll definitely need to put an amp to the sub to push it.

So what box is right for you? Well what kind of music do you listen to and what kind of setup are you going for? If you want a sq setup then like stated above definitely go sealed. If you want a spl setup then definitely go ported. But say you want a daily driver setup, then what? Well this can usually be answered by the type of music you like. If you like rap, techno, or songs with heavy bass and you really want to bring it out then I'd say ported. If you like rock, country, or styles around there with tighter bass then I'd say sealed.

Well what's the difference between ported and sealed? Ported is tuned to a frequency to optimize around that area, meaning it'll play a lot louder there. But as you move up the frequency curve generally around ~50Hz, there will be a sharp roll off where the other frequencies will almost sound muted compared to the low ones. Sealed on the other hand provides a smooth curve through the frequency range so it plays more evenly, the sacrifice to this would be the amplified low notes you get in ported.

Okay, so now it's time to apply power to your system, to really give it that extra kick it's been begging for. So how do you know what amp to use? Well theres a few different types of amps too, including:

• 1, 2, 3, 4, 5, or 6 channel
• Class A, A/B, D, G/H

I generally suggest to choose your speakers first, and then try to match an amp to the specs of the speaker. Well how do you match your amp? Your speaker whether it be a sub or door speaker has both a rms wattage rating and an ohm rating. You'll notice most amps can put out more rms power at a lower ohm load. This is because there's less resistance between the speaker and the power. However there is some amps out there that do constant power no matter what the ohm load the amp is seeing. Also I suggest choosing an amp that can produce about ~100rms or so more than what the speaker is rated at so you can cut the gain back to prevent clipping.

Now onto the classes of amps. This can get very technical so I'm just going to sum it up in basic terms. Generally class A, A/B, or G/H are used for door speakers because they can produce "cleaner" power to help prevent distortion where it would be highly noticeable. Class D amps or Mono block amps are generally used for subs where they can produce raw power and where distortion is barely noticeable.

Deadening a vehicle can greatly improve the sound quality of your system. If you go with components in a door, the deadening is a must otherwise you'll be losing precious midbass response. Now there's two main kinds of deadening both which do different things. These are cld tiles and then mass loading barriers. CLD tiles are used to help with vibration and bring out speaker response. Mass loading barriers are used to help cut down road noise, basically they're adding material to panels to block out sound in a simple way to state it.