Subwoofer Selection Tips From The Pro's

When deciding to upgrade your audio system, adding a subwoofer can produce massive results. Adding volume at sub frequencies is like adding a third dimension to your music. Whether you're considering building a new audio system, or just adding one (or more) subwoofers to your factory system, this addition will give you the single, largest sonic improvement. Simply adding even a little bass will make a HUGE improvement. You can also get free advice on choosing a subwoofer system from the pro's at www.apex-audio.com.
 
Choosing a car audio subwoofer can be confusing. There are a few questions that you should ask yourself before actually running out and buying woofers.

What type of sound are you looking for?
There are two main camps in the sound world: Sound Quality (SQ) or Sound Pressure Level (SPL).

Sound Quality alludes to just that - a very linear response that's not boomy and is very controlled, especially when listening to complex software. An SQ System generally uses a smaller woofer and requires a smaller enclosure. A sealed enclosure would typically work best for this application.

SPL, alternatively, is for you "Big Bass Lovers." If you're like me, and like a lot of impact with your music (extended bass response and 3 dB more efficient gain), then you're probably looking for a ported enclosure.

Sealed enclosures are also known as "Acoustic Suspension" enclosures. When a speaker is put in a sealed enclosure, the pressure becomes trapped in the box and restricts the cone movement, so the air inside the enclosure acts as a spring. The smaller the enclosure, the more pressure is exerted against the cone under movement. With a sealed enclosure of predetermined volume, we can also predict the cut-off frequency and Q* of the system.

Sealed enclosures will also forgive minor mistakes in design (up to 10 percent), without major effects on sonic performance.

The real advantage is that they just consume less space, not to mention they're simpler to design and construct. 

Ported enclosures are very close to a sealed enclosure in construction, but feature an additional opening for an attached port. This allows the rear-radiated energy to be phase inverted (matched in time) and to become in phase with the energy from the front of the speaker cone, essentially doubling the effective cone area.

The main disadvantage with a ported enclosure is that the design and construction are not very forgiving of mistakes. Unlike a sealed box, you must determine a number of parameters: the box volume, tuned frequency, port area, and port length. But, the advantage is great - you'll get more output with the same number and size of woofers.

However, with all of that extra output there's always a trade off. More bass naturally means more space. 

You're probably thinking, can a ported enclosure sound as well a sealed enclosure? The answer is, yes, but it's different in that it will have a slight peak around the tuning frequency (35 Hz) and roll off very quickly. Both types of enclosures have true supporters. What you use really boils down to your application and how they load in your vehicle.

How much space are you willing to give up?
Now, that you've clarified your music tastes, you'll need to decide which one of the enclosures will fit your needs and your vehicle. 

Before you make your purchase, it's also a key to find out how much air space and what type of enclosure is required for your dream woofers. Most manufacturers will have both specifications for sealed and ported applications. This information can be found several ways: through your local dealer, via the Internet, or by calling the manufacturer's technical department. When in doubt, ask your dealer to help you determine the best woofer(s) for your application.

How much money should you spend?
This can vary according to your personal needs. Many believe that the more you spend, the greater the bass you'll get. There surely is some truth to that, but I found that a lot of people get hung up on specs that really are not vital. This is a personal decision. Don't believe that spending more gets you more. Don't get hung up on specs that are not important.

Does the installation matter?
Absolutely. In a home system installation, where the installation is essentially plug-and-play, installation accounts for a very tiny percentage of the sound quality and is pretty impossible to screw it up. Most home receivers have everything built into a single unit and the engineers have taken most of the guesswork out. There's no level matching between components and definitely no subwoofer enclosure building. In a vehicle, it's much different - the installation takes a lot more finesse and accounts for about 80 percent of the success of how the system will sound. This is why it's so important to spend the time and money on how it's put together.

In fact, the installation is everything. Think of it this way: If you build a house with a poor foundation, the house will always have a poor foundation and will never be able to support the house. If you're installing it yourself, or if you're going to have your local shop put it in, do a little homework and it'll go a long way. Make sure you calculate the correct volume for your enclosure and use good quality materials like MDF or Fiberglass.

If you follow these tips, you too can reap the rewards of great bass from your car audio subwoofers..