When it comes to subwoofer sizes for car audio systems, many people think that bigger is better. While we won’t argue with the fact that a speaker with more cone area can be more efficient, the output capabilities of a subwoofer depend significantly on the enclosure it’s installed in. In this article, we are going to look at a sure-fire way to make sure you get the bass performance you want from your mobile audio system.

Why Do You Need a Car Audio Subwoofer?

Making good bass that is clear and loud requires a lot of air movement. A small 4-inch speaker in the dash of your car or truck simply can’t move far enough to pressurize and rarify enough air to make acceptable bass. Subwoofers are speakers that are designed to play frequencies below 100 Hz. These speakers feature large voice coils to dissipate large amounts of heat, with suspension designs that allow for lots of cone movement. When installed in a properly designed enclosure, subwoofers relieve the smaller speakers from having to try to play bass frequencies. Being able to focus on midrange information reduces cone excursion requirements and decreases distortion.

Subwoofer Size Versus Low-Frequency Extension

When buying a subwoofer, you need to determine how much space you’re willing to assign for the enclosure. Larger subwoofers require a larger enclosure to produce the same amount of low-frequency output as smaller-diameter subwoofers. To begin to understand this concept, let’s use a few examples. Say we have enough room to have an enclosure built with an internal air volume of 2 cubic feet. This is a very flexible size in that the options for subwoofer are extensive. We could use a pair of tens with the enclosure sealed, a pair of tens with a vented design, a pair of twelves sealed, or a single 12 in a vented design. Which is loudest? Which is best? Let’s have a look.

The graph below shows the predicted free-field output of a pair of ARC Audio Black Series 10-inch V2 subwoofers in a sealed and vented design with a total volume of about 2 cubic feet. The red curve is the sealed design and the orange curve is the vented design.

The vented design increases the total system efficiency at all frequencies from 20 Hz to beyond 100 Hz. In this simulation, the dual 10-inch vented design is the winner. What about using larger woofers? Let’s compare the performance of a pair of Black 10’s to a pair of Black 12 subwoofers. The yellow line in the graph below represents the predicted output of a pair of Black 12V2 subs.

As you can see, in this simulation, the response curve of the 12-inch subwoofers mimics that of the tens, but with an increase in efficiency of more than 3 dB.

Here’s where things start to get tricky. What about a pair of tens in a vented design as compared with a pair of twelves in a sealed enclosure? The graph below tells the tale.

Down to 25 Hz, the tens in the vented design are more efficient than the twelves in a sealed design. What if you want good efficiency and want to fill in that deficiency in efficiency below 25 Hz? How about throwing a simulation of a single twelve into the mix?

The green line added to the previous graph shows the response of a single ARC Audio Black 12V2 subwoofer in a 2-cubic-foot vented enclosure. It’s not as loud as the pair of tens or twelves above 30 Hz, but it’s the loudest at 20 Hz. It all depends on your choice of music and how much low-frequency extension you’re after.

More Subs Isn’t Always Better

We are going to add one more graph to our article. This graph shows the original pair of 10-inch Black-series subwoofers in the 2-cubic-foot sealed enclosure in red and the predicted response of using three of those subs in the same enclosure. Up at 70 or 80 Hz, there is some increase in output, but down around 30 or 40 Hz, where the fun bass exists in most music, the output is almost the same. So, is there an advantage to running three subwoofers in this enclosure? Not really.

What About Subwoofer Power Handling?

The final consideration in this discussion of the best subwoofer choice for a given amount of space is power handling. There are two types of power handling to take into consideration with subwoofers: thermal and physical. Thermal power handling is determined primarily by the size of the subwoofer voice coil. Larger coils can handle more heat. In the case of the Black subwoofers in this article, both subs have a 3-inch coil, but the 12 has a 500-watt RMS power rating as opposed to the 400-watt rating of the 10.

In terms of physical power handling, that’s something that needs to be evaluated in simulation software. The graph below shows how far the woofer cones move relative to frequency. The chart below shows the sealed tens in red and the vented tens in orange. With an Xmax spec of 16 mm, the vented enclosure is good to just around 22 Hz. At that point, the cone might bottom out. Adding an infrasonic filter at this frequency would help prevent damage. In reality, unless you’re deliberately playing music with lots of extremely deep bass, you should be fine.

Upgrade Your Car Stereo with a Subwoofer

If you’re heading to your local specialty mobile enhancement retailer to talk about adding a subwoofer to your audio system, start by planning how much space you can allot to the enclosure. This information will help the product specialist determine what size subwoofer and how many are best for your listening preferences.

This article is written and produced by the team at www.BestCarAudio.com. Reproduction or use of any kind is prohibited without the express written permission of 1sixty8 media.

For decades, companies have touted the benefits of high-end car audio RCA interconnect cables. When it comes to noise rejection, environmental stability and cosmetics, better cables are a great investment. In terms of improving sound quality, accuracy and detail, do more expensive cables sound better? Let’s take a look at the physics behind cable differences.

Are High-End Car Audio Cables Better?

If you look at the top car audio RCA interconnect offerings from Audison Connection, Wirez, Stinger, JL Audio and T-Spec, to name just a few, you’ll find that all of them share one common trait: they have features that help with noise rejection. The audio signals being passed from your source unit or processor to your amplifier are typically under 50 millivolts, even at moderate listening levels. If the interconnect cable passes by a computer module or a cable carrying significant amounts of current, it may pick up electrical noise. Shielding the signal cables is important to keeping noise out of your audio system.

More expensive cables often include more than one layer of noise shielding. When designed properly, this shielding can help to prevent noise in the form of electromagnetic interference (EMI) from being added to the audio signal. If you are worried about noise, look for a cable design that is shielded from one end to the other without interruption.

Can You Have Too Much Shielding?

Any time two conductors are adjacent to each other, the magnetic fields from one impose a current flow in the other. Depending on the geometry of the cable, extensive shielding around a conductor can act as a capacitor, potentially affecting the perceived frequency response of the cable. We’ve heard minute changes in the top octave when switching from an unshielded cable to one with significant foil or mylar film wraps. Ultimately, keeping noise out of an audio system is far more important than having to add a tenth of a dB to the tweeter settings on your digital signal processor. Is it worth worrying about? Not at all.

What’s the Hype About Twisted-Pair Cables?

Invented in 1881 by Alexander Graham Bell, twisted-pair cable geometry was originally designed for telephone systems. The act of spiraling the two conductors together reduced electromagnetic radiation from the pair, reduced crosstalk between the pair and improved the rejection of unwanted interference from other sources. While these benefits sound great, specific circuitry is required on the receiving end of the wires in order to make this cable geometry beneficial. You can read our article on differential inputs for a full explanation.

Home Audio Guys Upgrade Their Cables, so Shouldn’t I?

If you have been lured into the dark and murky waters of high-end home audio interconnect cable discussions, you can easily fall prey to strange and often mythical explanations about long-strand oxygen-free copper, silver conductors, ceramic connectors, high-voltage DC bias solutions and hundreds of other strange features.

There are two huge differences between home and mobile applications that need to be taken into consideration. First and foremost, car audio systems need frequency response calibration with an equalizer in order to sound good. The reflections from windows, plastic, vinyl, wood and leather wreak havoc with the frequency response of the system. It is this tuning that determines the frequency response of the system.

Second and of similar importance is that cars and trucks are not stationary. Vibrations from the engine, bumps in the road, and cornering, acceleration and braking forces put a lot of load on electrical connections. Car audio interconnects need integrated strain relief to prevent the conductors from work-hardening and breaking. While there may be exceptions, most home audio interconnects are not suitable for mobile applications.

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Good Cables Help Ensure Great Sound

If you already have a car audio system that sounds good, chances are that upgrading the interconnect cables won’t affect the overall performance enough to make the investment worthwhile. If you have noise issues, then using the right kind of cables for your equipment can help a lot! Cables won’t fix ground-loop problems, but they can help with EMI noise.

As a final thought, you will garner more benefit from upgrading your speakers than you will from upgrading any other part of the audio system. You can learn about what differentiates mediocre speakers from great ones in this article about car audio speaker upgrades and this one about speaker technologies.

If you want better sound from your car audio system, drop by your local specialty mobile enhancement retailer today and talk with them about your existing system and your goals. They can help you navigate through the thousands of options to make your system sound better.

This article is written and produced by the team at www.BestCarAudio.com. Reproduction or use of any kind is prohibited without the express written permission of 1sixty8 media.