Many professionals in the car audio industry started their careers as novices installing equipment for themselves or friends in their driveways and garages. That hands-on experience typically led to a job at a local shop and allowed them to learn more about electrical theory, acoustics, physics, and fabrication. Those who have invested time in understanding these advanced concepts offer impressive value to consumers. That said, this experience and efficiency come at a cost. Let’s look at the benefits and drawbacks of professional versus DIY car audio upgrades.

Consideration 1: Time

Let’s say you want to install a new radio in your car or truck. You’ll need to go to the store, audition several radio options, then purchase the radio and all the necessary installation accessories. These days, you likely need a data interface, wire harness adapter, antenna adapter, USB adapter, and a mounting kit.

When you get home, you’ll connect the harness from the radio to the wire harness adapter. Then, you have to take the dash apart. If you have an older vehicle, this could be as simple as removing a few screws. Some older vehicles required special keys or tools to remove the radio. In some vehicles, you might have to remove the glove box or center console trim and parts of the dash before the radio becomes accessible. You’ll also need to remove trim pieces around the windshield to run the hands-free mic. Speaking of the Bluetooth mic, you’ll need to know where to install it and how to secure the wire so that it doesn’t drop down in front of the windshield.

Connecting the wiring is usually pretty simple. However, finding a location for the new modules and connectors can be a pain. We know people who have spent more than an hour trying to get a new radio to fit into the dash because of all the extra wiring and magic interface boxes.

Vehicle Interface Modules

Speaking of modules, you’ll want to include a steering wheel button interface. Depending on the unit you purchase, getting this programmed and working can take another 30 to 60 minutes. You may also need access to a computer to program the interface, so downloads and drivers on a Windows PC are in your future.

If the project goes well, between making the purchase, wiring, installation, and clean-up, you’ll likely need at least four to five hours. If there are issues and you have to go back to the store, the time could easily increase by 50%.

On the other hand, if you have a professional do the installation, they will most likely have already worked on your vehicle’s make and model. Buying a radio and then having it installed typically takes less than two hours.

Winner: Professional Installation

Consideration 2: Cost

We aren’t saying that your time doesn’t have value. From the standpoint of the raw out-of-pocket cost to upgrade a radio or install an amplifier, your time is free. On the other hand, paying a professional to work on your vehicle will cost well over $100 an hour.

If you have an entire day available and want to try an installation yourself, that’s your decision. If you have a busy schedule with family, work, sports, and time with friends, then spending an entire day guessing how to take your car apart, where to connect wires, how to configure modules, and put the whole thing back together without buzzes or rattles might be less appealing.

Nevertheless, installing it yourself is effectively free.

Winner: DIY

Consideration 3: Risk

Now, you might think we were stacking the cards in favor of the professionals with the list of challenges associated with upgrading a radio or adding an amplifier. While this is true, there is a long list of potential issues in terms of DIY automotive work.

First, there is liability. What if something goes wrong? What if a wire or tool slips and you short the accessory output of the body control module to ground? A new BCM will cost hundreds of dollars and might need to be programmed into the vehicle, which is likely another $150. One slip could cost you $500, plus the time and cost of getting and installing the part. If the damage is severe, you might not be able to drive the vehicle until the component is replaced.

If you damage a trim piece, that will also be expensive. The trim pieces for either side of an older Ford F-150 radio are about $100 each, and an A-pillar for a Hyundai Sonata is about the same.

Taking cars apart is a skill. Knowing where clips and fasteners are located combines talent and technology. Professional shops often subscribe to services like ProDemand from Mitchell1. ProDemand offers detailed instructions on how to take different parts of the vehicle apart and reassemble them. Shops can pay up to a few hundred dollars a month for this information. They work on vehicles all day, every day. As such, the investment is worthwhile in ensuring your vehicle is put back together perfectly.

Most importantly, if a shop working on your car or truck breaks something, they will repair or replace it. If it’s significant, their insurance company will make it right. If you are working with a reputable mobile enhancement retailer, the odds of something going wrong are slim. However, knowing they will make it right in the long run is paramount.

Winner: Professional Installation

Consideration 4: Technology

Working on a modern vehicle audio system is stunningly complicated, even when it seems quite simple. A base-model radio with four or six speakers likely includes equalization, all-pass filters, and signal delays. Yes, even systems without amplifiers include these technologies.

For example, many Chrysler and Dodge vehicles use a woofer in the front door and a small midrange speaker in the dash or sail panel. If you upgrade that speaker without considering the equalization in the signal from the amp, the system will sound bright and harsh.

Professional shops have the tools and training needed to measure the performance of the factory-installed audio system. Using that information, they can suggest upgrade solutions that will make new speakers sound better.

What are the consequences of not having this information? As mentioned above, new, better speakers might sound worse than the originals. If you integrate with a line-output converter, you might overdrive the device. This condition would result in significant distortion and potentially damage the speakers. Knowing how the factory-installed system functions is crucial to designing an upgrade that will sound excellent.

Winner: Professional Installation

Consideration 5: Materials and Quality

You will need some supplies to perform a high-quality installation. Good-quality wire cutters and crimpers are essential. For crimpers, those multi-tool crimpers and strippers don’t work well. A set of dedicated wire crimping pliers is the bare minimum standard. As Panduit and 3M outline, the proper tool is a ratcheting crimper.

If you are installing a radio, you will also need zip ties and heat-shrink or maybe electrical tape. You can spend anywhere from pennies to dollars on electrical tape. Don’t skimp on what you buy if you want it to remain adhered in temperatures from -40 to almost 140.

Say you need to build a set of speaker mounting adapters. Professional shops no longer use wood for adapters. Materials like expanded PVC, acrylic, ABS, Corian, or even aluminum are impervious to water damage. Further, they can be shaped to mimic the original mounting and are effective against water damage. You will need a router, a router lift, and a selection of cutting bits to make these adapters look like they belong. So, tack on another $1,000 for that.

You can certainly purchase any of these items or materials. However, you likely have to buy significantly more material than you’ll ever need. You’ll also have to invest in the tools to make the parts.

Winner: Professional Installation

Consideration 6: System Configuration and Calibration

One installation aspect that is continually overlooked is system configuration and calibration. Let’s say you’ve purchased a new radio. If it’s a mid-level or higher model, it likely has a 10-band equalizer, at the very least. Leaving this unconfigured is like ordering chicken wings without sauce at Duffs in Niagara Falls, NY. You’re going to miss out on something important.

Suppose your audio system includes adding a subwoofer and amplifier; testing to ensure the acoustic polarity between the sub and the rest of the speakers is crucial. If the system has a digital signal processor, adjusting the relative phase around this crossover point may be possible. Getting this right is crucial to making the system sound amazing.

Once again, it’s possible to purchase all this hardware and invest time in learning how to use it, but that will cost at least a few hundred dollars and require days of research and experimentation.

Winner: Professional Installation

What is Professional Car Audio Installation?

Searching for a shop to upgrade your vehicle starts with visiting the shops in your area. Ask the Product Specialist the same questions and consider their responses carefully. Are they working to help you find a solution that matches your goals, or are they more focused on maximizing their profits? Look at the shop’s website and social media. Do they have examples of their work, or are they just focused on selling as many boxes as possible to anyone who comes through their doors?

Study Their Work

Speaking of work, ask to see examples of what they’ve done. Look at the wiring. Is it tidy? Is it safe? Do they waste time making wiring look fancy, or is it hidden and properly protected? Look at how equipment is secured to the vehicle. Will a subwoofer enclosure stay in place, or will it become a lethal projectile in the event of an accident? Attention to detail is the name of the game here.

Ask about warranty coverage. What warranty do they offer on their workmanship? What are their policies on product warranty? Do you have to pay for removal and reinstallation? What about paying for shipping? Do they offer an over-the-counter exchange program on products they have installed? Do any of these policies apply to cash-and-carry items?

Professional or DIY Car Audio Upgrades

We do not doubt that we’ll get a LOT of feedback on this topic. There are excellent examples of DIY car audio upgrades. Sadly, there are hundreds of times as many examples of poor or dangerous work. As much fun as it is to tinker, your car is a complex machine. Vehicle manufacturers put a stunning amount of emphasis on reliability and safety when they design it.

If you want your car audio system to sound better, start researching which shop in your area does the best work and offers the highest-performing products for the money. Look for retailers with MECP Certified Product Specialists and Installation Technicians. Work with them to design an upgrade that fits your budget, meets your performance goals, and provides the best reliability. We know you’ll be happy with the investment if you choose wisely.

Lead-in image: On the left is a custom subwoofer enclosure created by Musicar Northwest in Portland, OR. It houses a single 10-inch driver and, most crucially, looks like it belongs in the vehicle. On the right is an amateur installation brought to Broken Silence Car Audio in Greenwich, CT, to be fixed—the ‘after’ photo is shown above.

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.

While participating in some brand-specific online discussion groups, we often encounter the question: “Is it better to use two good subs or one great one?” Are two 12-inch KICKER L7S subs better than a SoloX? Should you opt for two Hertz Cento CS 250 S4s instead of a Mille ML 2500.3 Legend? What about choosing a pair of Rockford Fosgate P3 twelves over a single T1? There are many factors to consider, including enclosure design, output, frequency response and efficiency. Let’s dive into science and math to find an answer.

Maximum Output Level – Part 1

For many car audio enthusiasts, achieving the most bass possible from a given investment is the top priority. So, is a great subwoofer louder than two good subwoofers? Let’s use the CompVR and CompVX subwoofers from KICKER as our first comparison.

We’ll start by setting aside the total enclosure size for now. While this will become important later, let’s first model a pair of KICKER CompVR CVR124 12-inch subwoofers using BassBox Pro.

KICKER recommends an enclosure volume between 1.75 and 2.25 cubic feet per driver for a bass reflex enclosure. We’ve split the difference, using two cubic feet per driver. We let BassBox Pro suggest a tuning frequency of 33 hertz. According to the simulation, the enclosure will produce 123.1 dB, with each subwoofer receiving 400 watts of power. Remember that this SPL number doesn’t account for the vehicle transfer function, meaning the output would be higher in a car or truck.

Now, let’s switch our focus to the CompVX cast-basket 12-inch subwoofer. This driver handles up to 750 watts of power and has an Xmax specification of 19.25 millimeters compared to the CompVR’s 16.5. Let’s see if this makes up for the output difference.

In this case, the single great subwoofer cannot match the output of the two good subs when driven by the same power.

One quick note about the KICKER simulations. KICKER doesn’t specify driver inductance. For this simulation, we left that field blank. The result is a flat response curve at midbass and midrange frequencies. In the real world, that’s not how the drivers would perform in that region.

Maximum Output Level – Part 2

Now, let’s consider a similar scenario with Rockford Fosgate subwoofers. This question initially prompted the article—are two P3 subwoofers better than a single T1? Let’s simulate this and see which setup produces more SPL.

We’ll start by simulating two P3D2-12 12-inch subwoofers in a 3.58 cubic foot enclosure tuned to 40 hertz. The Box Advisor on the Rockford Fosgate website suggests this exact design. Well, it suggested half that volume per driver, but the results are the same.

As the graph shows, this enclosure delivers a solid punch at 50 hertz. With 1200 watts of power, the peak output is predicted to be 125.7 dB SPL.

Next, let’s examine what a single Power Series T1D4-12 can do in its recommended enclosure.

The Box Advisor recommends a 1.75 cubic foot enclosure tuned to 33 hertz for the single T1 subwoofer. Based on the response graph, we agree with this design. The enclosure predicts an output of 119.1 dB SPL when driven by 800 watts of power.

Like in car engines, there is no replacement for displacement when attempting to produce maximum torque. Subwoofer cone area is crucial for maximum output in car audio systems.

Low-Frequency Extension Versus Enclosure Volume

What if your goal is to achieve the most low-frequency output possible from your subwoofer system? Many of the subwoofer upgrades we see perform better at upper bass frequencies due to large drivers being installed in undersized enclosures. If deep bass is your priority, moderately sized subwoofers in relatively large enclosures are the way to go. To illustrate this, let’s compare two Hertz subwoofer options at 30 Hz.

We’ll begin with a pair of 10-inch Hertz Cento CS 250 S4 subwoofers in a 2.5 cubic foot enclosure tuned to 30 hertz.

This system produces 113.9 dB SPL at 30 hertz. Now, let’s look at a single, better subwoofer in a larger enclosure—the Mille-Series ML 2500.3 Legend.

At 30 hertz, the single ML 2500.3 Legend delivers 114.5 dB SPL. Though the difference is slight, the difference would be very noticeable. Letting a single driver “breathe” in a larger enclosure maximizes low-frequency output.

Car Audio Subwoofer Sound Quality

This is where things become more complex. Sound quality and accuracy are not as tightly related to frequency response as you might think. We agree that a poorly designed enclosure with a narrow-band spike will sound inferior to a system with a broad response curve. However, a subwoofer in any high-end system should be equalized to a target response curve. Thus, any two enclosures equalized to the same curve will sound similar, though not identical.

Driver design features affect harmonic and intermodulation distortion in terms of accuracy. For instance, the Mille Legend subwoofers include an aluminum shorting ring that reduces inductance and, thus, improves midbass response. The Legend subwoofer’s inductance is specified at 1.05 millihenries, while the Cento subs measure 3.33 millihenries. Lower inductance means more midbass output, making blending the subwoofer’s output with midbass drivers easier.

Rockford Fosgate incorporates a similar feature between the P3 and T1 subwoofers. The T1 and higher subwoofers feature an Inductive Damping Heat Sink (IDHS) that acts like a shorting ring, reducing inductance. The T1’s dual four-ohm inductance is 2.4 millihenries, while the P3 is rated at 6.94. As a result, the T1 delivers tighter, punchier, and more accurate midbass.

Even without features like inductance management, less expensive subwoofers are still a great choice. However, upgrading to better products often provides more than increased excursion and power handling.

From a sound quality and musical accuracy perspective, the Mille and Power-Series subwoofers stand out as clear winners.

Space for Bass

As we’ve discussed in previous articles, producing deep bass requires that your subwoofers have adequate space. Trying to fit two 10-inch subwoofers in a one-cubic-foot enclosure won’t work as well as using a single eight-inch driver in a bass reflex design in the same volume.

Here’s a perfect example of optimizing an enclosure for subwoofer duties. A single 8-inch Audison APS 8 D driver in a one-cubic-foot vented enclosure delivers more output from 16 to 44 hertz than two 10-inch drivers in the same space. While two 10s might offer more output above 50 Hz, we prefer deeper extension to 35 Hz for a well-rounded sound and a little rumble.

Subwoofer Enclosure Simulations To The Rescue

In conclusion, if your goal is to maximize SPL, using two good subs will generally outperform a single sub. However, a single subwoofer in a larger enclosure may be the better option for low-frequency output. A subwoofer with advanced performance features will offer superior results for the most accurate and detailed bass.

If you’re curious about the best bass solution for your vehicle, visit a local specialty mobile enhancement retailer. They can measure the available space and simulate different subwoofer options to achieve your desired performance. They’ll also explain product features and how they improve sound accuracy and detail.

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.