Car speaker placement is very important to the overall sound of a car audio system. When installing car speakers there are two choices, factory locations or custom locations. Factory locations are convenient for drop in replacements but for the best sound, custom work is often needed. Let me offer some car speaker installation advice.
Factory locations are often chosen by the manufacturers as an afterthought. After the rest of car is designed, car speaker placement is decided. The most common locations for installing car speakers are the dash, the doors and the rear deck. These will be adequate for most of the population and are good choices for simple speaker upgrades.
The custom location of choice is usually the kickpanel. The kickpanel is the area under the dash in the far left and far right corners of the car's interior. It may seem that installing car speakers in this area is foolish. After all, how can having speakers at your feet be the best choice for car speaker placement? The answer has to do with time alignment. Think of how your home stereo is set up. When you sit in front of your speakers they are probably both an equal distance from you while you sit in the middle. This gives you perfect balance. Now think about your car. With the factory car speaker placement in the dash or doors, how far are you from the left speaker? Now how far are you from the right speaker. There is a big difference.
That's why the best car speaker imaging advice I can give is to put speakers in the kickpanels. Speakers in the kickpanels will be more close to the balanced ideal of your home stereo system. The soundstage will be placed more in the center of your listening area instead of skewed to one side. The distance from the floor to your ears will probably not be noticed. This is because humans are more sensitive to location in the horizontal plane than in the vertical plane.
Q-Logic makes a line of custom kickpanel speaker pods for a variety of vehicles. This may be cheaper than having true custom work done. The price is about $200 a pair. Compare this to your local shop to see which is a better option for you. If you want to build your own kickpanels then you might be interested in one of our DVD packages that includes Car Audio Fiberglass Fabrication I. This DVD covers custom kick panel fabrication as well as other popular fiberglass projects.
Kickpanels are the space right in front of the front door, near the floor. Basically where the floor, side panel and firewall meet. See the image below. Kickpanels are a very popular place to put aftermarket speakers, especially in car audio competitions. Some companies even specialize in the production of kickpanel replacement pods that allow easy installation of speakers into the kickpanel area.
But why are kickpanels so popular? Doesn't it seem that your feet are a terrible place to put speakers?
Think about a home stereo system. How are the speakers positioned and where do you sit? Ideally both speakers will be an equal distance from you and your listening position will be directly in the middle as in the diagram below. This is the ideal listening position as it places you directly in the middle of the stereo pair which is necessary for a proper soundstage. NOTE: A soundstage refers to the imaginary area that is created by our brains when the stereo information (music) we hear in both ears is combined. With a properly set up speaker system you will be able to close your eyes and point out where each instrument is on the stage. This is why it is important to get the distances d1 and d2 as equal as possible. Major differences in distance will skew the soundstage to the left or right.
Now think about your listening position in a vehicle. If you're the driver then you'll be sitting closer to one side of the vehicle while your passenger is sitting closer to the other side of the vehicle. Now put a pair of speakers in the doors and notice the distance you are to one speaker as compared to the distance to the other speaker. See the diagram below.
You'll notice that the distance to the closest speaker, d1 is much less than the distance to the far speaker, d2. This will cause the speaker closest to you to be louder in volume and have a shorter arrival time. Both of these factors will cause the soundstage to be thrown off. Now put a pair of speakers in the kickpanels and notice how the distances d1 and d2, while still not equal, are closer to being equal than the door speakers. See the diagram below.
This will bring the soundstage together much better than door mounted locations and is a major reason why kickpanel speakers are used so often in car audio competitions (where soundstage is usually a judging criteria).
But what about having speakers at your feet? Won't it sound like the band is playing at your ankles? Not if the system is set up properly. And some vehicles are better than others. Vehicles that have the passengers sitting high (SUVs, minivans, trucks) will have a much larger distance to overcome than a passenger car. However, humans can localize sounds much better in the horizontal plane (left to right) then we can in the vertical plane (up and down). Even though the speakers are at your feet you should still hear the speakers as being in front of you at eye level. Sometimes your brain will take over and tell you to hear the speakers at your feet because you know they are there. But if you close your eyes (not while driving of course) the illusion should return.
Another advantage of kickpanel speakers is that the woofer/midrange and tweeter will be mounted very close to each other. This is close to the point source ideal. We would like to be able to produce all of the midrange and high frequencies with one driver but unfortunately this is not possible so we need at least two drivers. Now that we have two drivers we also have two sources of sound, the midrange speaker and the tweeter. If these two sources are separated by too great a distance from each other there will be problems. Think of a human singing voice. If the singer is able to produce notes in both the midrange and tweeter frequencies then all of those notes need to appear to come from the same place or the singer's voice will appear to jump between the midrange speaker and the tweeter. If the midrange is mounted in the door and the tweeter is mounted on the dash then there will be a large distance between the speakers and between the speakers and the passengers. By placing the speakers close together this distance will be much less and will be closer to the point source ideal (one source or point of sound).
Since speakers mounted in the kickpanels will be so close to the passenger's feet there is a much greater chance of damage than a speaker mounted behind a door grill. Make sure you or your installer adequately protects your speakers from damage by using appropriate speaker grills or other protection methods. Also make sure the speakers are protected from moisture found on dirty footwear.
You should also check out Fiberglass Fabrication I. It covers an introduction to fiberglass work with sections on kick panel speakers pods, MDF enclosures with curved fiberglass baffles and spare tire subwoofer enclosures. Click here.