SUBWOOFERS - A MUST FOR A SOUND SYSTEM
When it’s time to enjoy great music in your car, subwoofers are crucial. Because they reproduce low frequencies (bass), adding depth, warmth, and physical impact to your preferred music, something full-range speakers can't do on their own, subwoofers will bring liveliness to the best tunes. This creates a more immersive, detailed, and dynamic audio experience, even at low volumes.
The subwoofer also takes some of the load off the main speakers, improving their clarity while still allowing you to listen loudly without distortion.
Why are they important?
- They add the physical and emotional dimensions of low frequencies (deep notes, explosive impacts), making music sound more realistic.
- They handle the low frequencies your main speakers can't or struggle to reproduce.
- By delegating the bass to the subwoofer, the full-range speakers in your car will focus on the mid and high frequencies, delivering clearer vocals and more detailed soundscapes.
- They allow you to listen loudly without distortion, with punchy and well-controlled bass, enhancing the musical dynamics.
- They allow you to fully experience the music even at low volumes, while keeping all the details and dynamism.
DEALING WITH POWER
As it is with musical instruments, none of those can perfectly reproduce every single note for all the audio bandwidth. Speakers also have their own limitations. From low to high frequencies, a group of speakers, where each element plays their own dedicated and specific role, will be more efficient than having a single speaker handling everything.
Each speaker has its own characteristics; therefore, you'll need to match the quality and power of your amplifier(s) to each speaker to get the most out of them.
As with our car comparison, too much power can be detrimental if mismanaged. On the other side of the spectrum, too little power will be just as detrimental if not more. The rule of thumb here is that a speaker will always deliver its best performance at the recommended power, no more, no less!
A good speaker should not create distortion when generating the air movement required to create your music. To achieve this, the cone must be rigid, so as not to deform under the thrust of the motor unit (speaker coil & magnet), but also light to maintain all its dynamism and limit any possible inertia. The perfect design for a speaker does not exist; This will always be a question of balance/trade off and a choice to improve one characteristic to the detriment of another. You also need to keep in mind that the lower the frequencies are, the more difficult it is to move the air to generate sound. Therefore, larger speakers are needed to reach required levels at those frequencies, and therefore, a heavier cone, which requires more power to reach the same output level as a smaller speaker. This is typically why we find subwoofers on the market with power ratings 3 to 5 times higher, if not more, than the typical power rating for a full-range speaker.
Because low frequencies require even more power, and therefore more heat dissipation, the rule of applying amplification power equivalent to a speaker's rated power is ten times more important for a subwoofer than it is for any other speaker. Here, absolutely do NOT compromise!
SECURING THE BEST LOCATION
Where to Install It
The ideal location for a subwoofer will depend on your vehicle type and the acoustic goals you're aiming for. In most situations, the trunk of your car will be the best place in over 80% of cases. Also, thanks to the raised seating design of many SUVs and other vehicles on the market, such as full-size pickup trucks, you also have the option, depending on their size, of installing your subwoofers under the seats.
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In the Trunk
- This is the preferred location for larger subwoofers to maximize power and bass depth.
- Pointing your subwoofers towards the tailgate or taillights, about a foot (30 cm) or less from the side panel, will allow the sound waves to bounce off the bodywork, which will enhance your low frequencies and produce a more powerful sound in the cabin.
- Positioning the subwoofer in an extreme corner (near the taillights) can also significantly increase its effectiveness.
- Another very popular choice due to its versatility is a down firing subwoofer design, mounted on feet a few inches (cm) from the floor. This protects the speaker from items left in your trunk and maintains a more discreet aesthetic, protecting you from prying eyes when you open your trunk lid or your tailgate. (See example below with a TS-A3000LB)
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Under the Seats
- Thanks to new technologies and slim subwoofers, requiring less space in volume and mounting depth, you can now utilize small spaces that are often wasted or unused on a daily basis. Consider slim subwoofers under the back seat of a full-size truck, or a smaller, slim subwoofer under the bucket seats of your SUV.
- Its immediate proximity and the fact that it shares the same space with the vehicle's occupants will provide a more direct listening experience, improved bass response, and enhanced sound immersion.
- These solutions can be offered by creating your own “recipe” by pairing an amplifier with these slim subwoofers, with your own box design, already preloaded in its box, or by using an all-in-one solution consisting of a small amplified subwoofer unit like the TS-WX140DA in the following picture.
- Because these small subwoofers typically use limited space inside a sealed enclosure, they will show slightly lower efficiency than a larger subwoofer using a bass-reflex enclosure. However, if properly integrated, they can be a surprisingly good choice for balanced, high-quality music listening.
FEW TIPS FOR PHYSICAL INSTALLATION
Even if you buy the best subwoofer available, if you don't install it properly and according to best practices, you won't get the best performance from it. To maximize your investment, make sure to:
- Maintain a few inches (cm) of clearance between the speaker and the interior walls of your car to avoid muffling the sound.
- Test different orientations (upward, backward, forward), as each car’s interior, depending on its shape and materials, will react differently to sound waves and how they are reflected or partially absorbed.
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Securely mount the enclosure to the chassis (metal sheet/structure) of your vehicle:
- To prevent it from moving during sudden braking and ensure a safe installation.
- To create a solid foundation for its main structure (the enclosure itself) so that it doesn't move in the opposite direction to the subwoofer's thrust. Any movement of this enclosure will reduce the power and acoustic quality of your subwoofer. For this purpose, Pioneer includes the required accessories and mounting brackets to secure our preloaded subwoofers and all-in-one amplified subwoofers from our TS-WX series.
SUBWOOFERS TYPES AND OFFERS
To save you from a long listing and describing all the different types of subwoofers available on the market, the major offerings of popular products fall into the following categories:
Subwoofers sold individually
These subwoofers can be purchased individually, for which you will need to design and build a suitable enclosure, following the manufacturer's recommendations to achieve the best performance, and of course, connect them to a dedicated power amplifier that will perfectly match the power handling of your selected subwoofers.
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"Classic" subwoofers
- Conventional construction with a standard speaker basket that requires fairly good clearance behind the speaker unit, approximately half its depth, or even more for some models.
- These subwoofers are the preferred choice for serious bass enthusiasts who have the space required for these larger subwoofer formats and who also require larger enclosures that are normally bass-reflex boxes.
- Our "CHAMPION" series subwoofers our classic "D Series" or, again, the “PRO Series” subwoofers are excellent examples of this type of speaker.
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"Slim" Subwoofers
- This design has emerged in recent years to meet the increased demand for smaller space in vehicles and/or to offer more installation options thanks to its shallower mounting depth. This depth is typically one third of the subwoofer's diameter, or even less for some models.
- Since these speakers are normally optimized to use as little space as possible, they will be optimized to work inside small, sealed speaker boxes.
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You will find various Pioneer offerings here:
- Z Series Slim Subwoofers (Best)
- D Series Slim Subwoofers (Better)
- A Series Slim Subwoofers (Good)
Preloaded Subwoofers (Passive)
These solutions simplify your purchasing and installation process by providing a subwoofer already installed inside an enclosure. While you still need to connect your subwoofer to an external amplifier, choosing this type of product saves you the hassle of researching and building your own enclosure.
Pros:
- Time savings
- An enclosure designed specifically to meet the manufacturer's specifications
- Savings and “headache-free” process for those less handy who might struggle to achieve a quality result by building their own enclosure.
Cons:
- This type of offer is not available for higher-end subwoofer models, such as the Z Series.
- You will be limited to the generic dimensions of the enclosure. Therefore, ensure that it is compatible with the available space in your car.
Amplified subwoofers (All-In-One)
These solutions, offered to meet two types of customer needs, are typically available as follows:
- A solution addressing a specific need with “Small” as the keyword, requiring both low power consumption and a small footprint or reduced vehicle cargo space or,
- An affordable and easy to install solution for someone looking for an easy-to-install bass solution, whether using an original equipment manufacturer (OEM) or aftermarket radio, and who has a limited budget.
The "Budget" version of these products is typically offered by Pioneer as a trunk-mounted unit, usually incorporating more conventionally constructed subwoofers and being larger than the products mentioned in the first category. (See our TS-WX1010A or TS-WX1210A as examples.)
The "Small Size & Low Power Consumption" solution will integrate our latest technologies to meet the typical needs of a customer looking to improve the acoustic performance of their everyday vehicle without compromising interior space or aesthetics. Furthermore, with the arrival of new types of vehicles—electric, hybrid, and others—the need for energy efficiency is constantly increasing, making these solutions extremely attractive.
Don't be fooled by their small size, though. It's important to understand that, in the case of our TS-WX solutions, Pioneer manages every component: the power supply, amplification, subwoofer, enclosure, and overall acoustic treatment, ensuring they all work in perfect harmony. There's no better way to optimize product design and maintain complete control. Think of them as being to the small subwoofers what the iPhone is to smartphones. (See our TS-WX400DA or TS-WX140DA as examples.)
DEALING WITH ENCLOSURES (BOXES)
Types of Subwoofer Enclosures
Just as we have different types of subwoofers, we also have different types of enclosures available for subwoofers on the market. Here, I'd like to draw your attention specifically to the two most popular formats: the box enclosure and the vented enclosure, also known as bass reflex boxes. It's important to note that, even if you have the best subwoofer, if you don't install it in the right enclosure, one that meets the specifications, you'll never get good results. Some subwoofers are specifically designed for a sealed enclosure, others for a bass reflex, and some designs are compatible with both. Each enclosure design has its advantages and disadvantages; it's up to you to select the right model and the right subwoofer to achieve your goals.
The Sealed Enclosure
The sealed enclosure is the simplest design to create. It's simply an airtight box with a specific volume, determined by your subwoofer's specifications. This type of enclosure is generally the best choice for those seeking a natural sound within low frequencies.
Pros:
- Design requires the smallest possible air volume.
- Allows for better control and faster response from your subwoofer.
- Offers improved dynamics, especially with the extremely low bass.
- Maintains more linear excursion control across a large portion of the audio frequency range.
- Typically produces a more natural and linear frequency response curve.
- Lower phase-shift and better group delay minimizing possible phase issues for in-car integration
Cons:
- Slight loss of efficiency due to internal air compression.
- Less efficient at low power levels, particularly at the lowest frequencies.
This type of enclosure is becoming increasingly popular due to the growing demand for slimmer subwoofers requiring smaller enclosure volumes. It is, however, very important to note that a slim subwoofer is not necessarily designed to operate in small spaces. Do your homework and research to verify the frequency response patterns produced by these subwoofers when placed inside the enclosures you intend to use in your setup. You will be surprised to see that the results vary greatly from one manufacturer or model to another. For an audiophile setup, the goal is to obtain a frequency response curve with a Q factor of 0.707 once the subwoofer is in the enclosure.
The Bass-Reflex Enclosure
This enclosure design uses a passive resonance system to amplify certain low frequencies and increase the output of your subwoofer. This passive resonator typically consists of a tube integrated into the enclosure, either round or rectangular in shape. This "opening" must be precisely calculated based on the enclosure's volume and your subwoofer's specifications. When the subwoofer excursion occurs, the internal air pressures of the enclosure interact with the air volume in the ventilation tube, creating, depending on the frequencies and excursion, a bidirectional airflow that takes over from the subwoofer to produce greater amplitude at certain frequencies.
Pros:
- Produces significantly more bass with less power
- Allows you to feel the very low frequencies and generates more air movement.
- Depending on the subwoofer and tuning, this design can generate deep bass with more intensity and efficiency than a sealed box design
Cons:
- Bass may be less fast and exhibit less precision and dynamism than a sealed box design.
- The typical frequency response curve will be less smooth, usually exhibiting peak efficiency over a specific range before dropping off significantly in frequencies below the box's calibrated resonant frequency.
- Significant power loss at frequencies below the box's calibrated resonant frequency. (Be sure to calibrate correctly!)
- Air movement within the tube can generate more or less ventilation noise depending on the design.
- Larger box volume and more complex to manufacture than a sealed box. This design features a significant phase shift and group delay compared to a sealed enclosure, making it more complex to integrate with other speakers.
This type of design is highly valued by those who appreciate more pronounced bass frequencies and high efficiency. It is often the preferred choice for sonic enthusiasts seeking a high SPL (Sound Pressure Level), where every decibel counts.
Which box design should I choose?
To choose between a sealed enclosure design and a bass-reflex enclosure, you must first consider your sonic preferences and objectives.
- A sealed enclosure provides precise and dynamic bass, but is slightly less efficient (decibels/watts generated) and requires a smaller air volume, thus taking up less space.
- A bass-reflex enclosure delivers more powerful, deeper, and more efficient bass, but is slightly less musical and requires a larger air volume, resulting in a greater loss of cargo space.
IMPORTANT!
Then, if you have carefully read and understood the information above, it will be important to select the right type of enclosure, BUT ALSO to choose a suitable subwoofer.
Depending on the design, some subwoofers are optimized for better acoustic performance inside sealed enclosures, while others are optimized for bass-reflex enclosures. To effectively determine the right match, you will need to refer to the subwoofer's "Thiele/Small" parameters.
- Fs, the subwoofer's typical resonant frequency
- Qes, the subwoofer's electrical damping factor
Dividing the resonant frequency by the electrical damping factor (Fs/Qes) gives you an "EBP" (Efficient Bandwidth Product) value, which will allow you to determine whether the subwoofer is optimized for a sealed or bass-reflex enclosure.
- Any value below 50 confirms a subwoofer optimized for sealed enclosure.
- A value between 50 and 100 will allow for either type (depending on your preferences and needs).
- Any value above 100 confirms a subwoofer optimized for a bass-reflex enclosure.
Conclusion
We have now reached the end of this article and the key takeaway is that there are no bad subwoofers, but rather that the choices and combination of technologies and designs you make, based on your needs and installation limitations, will result in either excellent results or disappointments. This is one of the main reasons why Pioneer offers different technologies, formats, and subwoofer series to better meet these diverse needs. You now have the tools at your disposal; it's up to you to decide whether you'll use a hammer to build something great or hit your fingers!
