Put up an ad on Facebook about a subwoofer sale in Miami and masses of interested parties will either call and or show up asking about, how much bass do these put out, how many DBs, will I need a bigger AMP? Honestly, I have no idea why are subwoofer, especially car subs, are such a hot topic of conversation within the Miami car stereo community. But nevertheless, I have decided to state some fact and hope that this makes your car subwoofer shopping experience a little less stressful and a little more fruitful!
What do I mean by fruitful? Well, there is nothing more sad and disappointing than the wrong woofer for the application! And by that, I mean more inches does not mean more bass, and more magnet does not mean more power! I guess I’ll start by saying the subwoofers “don’t have power.” A subwoofer is a speaker designed to reproduce the first octave of the human hearing spectrum. That usually means a speaker capable of reproducing sounds between 20hz and 40Hz. Believed or not this one on the most difficult things to do because it can be a little tricky to get frequencies this low to resonate in a given environment. A subwoofer, as many other speakers is an electro-magnetic motor that drives or pushes on a piston called “the cone.” When placed in a resonating chamber more often than not called a subwoofer bao or enclosure it produces a resonation frequency equivalent to its electrical properties. The electrical properties of a speaker are dictated by its coil. When an AC (alternating current) is applied to the coil, it generates an electromagnetic field the changes in polarity as the AC signal. This field then reacts in relation to the polarity of the magnet in the motor of the drivers. Please know that today there are subwoofers without magnets and or coils that employ other technologies. Other speaker technologies include “servo-driven” and electrostatic! Since these technologies are usually beyond the budget of many car audio enthusiasts, I don’t feel it is necessary to spean a lot of time on it, but I just wanted to put it out there!
The best car sub for your car is not the largest one, the most expensive and or the one on sale! Before you chose a subwoofer, you have to take into consideration how much of your vehicle’s real estate are you willing to sacrifice? That question is directly connected to the type of subwoofer box or enclosure you choose! While there at least a dozen types of sub enclosures that come to mind the four that are most common in the car stereo marketplace are infinite baffle, sealed, ported, and bandpass. Every one of these has a very unique sound, and tone quality so let’s explain!
The infinite baffle application is not common in the car audio world today because more than 75% of all vehicles on the road are either hatchbacks and SUVs. Also known as “Free Air” this type of speaker enclosure is not an enclosure at all! It relies on a boundary or wall to separate the frontal waves of the speakers from canceling by those generated from the back. To accomplish this on a vehicle, you will need to build a wall (babble board) between the trunk area and the passenger compartment. In my opinion, this is the best sounding subwoofer application. It produces a tight and precise bass note that is not artificial or boomy! The best sounding car I have ever heard (Richard Clark’s 87’ Buick Grand National) employed a very similar setup with the addition of AP membranes. The infinite baffle setup offers superb sound quality with minimum weight while sacrificing SPL and power handling.
The sealed enclosure or sealed subwoofer box as it is often referred to is a simple as it comes. A sealed box designed to match the Vas or acoustic compliance of the drive. I have never been a true fan of the sealed enclosure for one reason and one reason only! Given the nature of the design sealed subwoofer boxes are not very efficient and often require three to four times the power assigned to your mids and highs to keep the bass from getting drowned by the music. In other words if you plan to have a 100-watt amp for your mids and highs, consider 400 to 500 watts for your sub. Sealed Enclosures allow drivers to handle quite a bit of power as long as the enclosure is “truly sealed.” That is something that can be challenging to achieve and relative light due to their compact natures. Some car stereo shops allow for a little bit of leakage to minimized cone damage in high powered systems.
If you like Miami style 2 Live Crew or Trick Daddy boomy bass, you may want to consider a ported subwoofer enclosure for your car. While slightly larger than a sealed box (often about 1.4 – 1.75 times larger), when properly designed and tuned a Porte enclosure can provide a considerable amount of bass with a moderate amount of power. The design consists of a common chamber enclosure with a port that is tuned to allow the waves from the rear of the speaker to get added to the form of the speaker 180 degrees out of phase. This type of acoustic coupling allows for as much as 40% improved efficiency over a sealed enclosure. The added efficiency come at a cost. Ported enclosures are known for allowing an excessive amount of cone travel below the tunning frequency of the box resulting in speaker damage or failure. Consider this type of enclosure for an SUV or hatchback, with the speakers facing back.
While companies like BOSE have proven that the bandpass enclosure can challenge both the sealed and ported designs, they can also be the most challenging to build and design. If you are trying to get it right! At its most simple design a bandpass subwoofer box consists of a front a rear chamber with at least one ported to the outside. Both can also be ported to the outside as well as within. There is at least a dozen variation but before you start building or selling bandpass enclosure, know that some designs are patented by companies like BOSE. Unlike ported and sealed enclosures where you can wink and guess the size, and tunning bandpass design required precise dimensions and calculation. The objective of the bandpass design is to give you the sound of the ported enclosure with the low distortion and power handling of the sealed type. Due to size, weight, and complexity, not the best choice for a car!
As you can see, the claims many manufacturers and retailers push, claiming this subwoofer is better than that one, etc., it redicules. The best subwoofer is the one that will best match your sound system. After many years in the Miami car audio scene, I tend to suggest starting with one, and in many cases consider employing what is known as bridged mono configuration if you already have an amplifier. That way, you can get a feel for how much bass you want and how many subs you need before making a huge investment. In addition to that and if may ofer a piece of advice! Seek quality, not quantity. A 150 dB sound system is as practical as a 2500 horse powered nitro-burning street-legal pro mod! Once you come to appreciate what a good sounding car stereo system sounds like how many watts, how many speakers and how loud a system can get becomes irrelevant.