High-quality speakers and proper installation are crucial when upgrading your car’s audio system. The ease with which your installer can reliably integrate tweeters into your vehicle will determine a portion of the labor cost. Will the technician need to fabricate a mounting bracket? Will they need to create a little pod? Is there even enough hardware provided to ensure a reliable and safe installation? Let’s look at some tweeter installation hardware solutions.

Why Are Tweeters Important for Great Sound Quality?

Before discussing tweeter installation, we should review the importance of having dedicated tweeters in a car audio system. By definition, tweeters are relatively small speakers designed to play the highest audible frequencies. They vary from 0.5 to over 1.25 inches in size. The larger tweeters can typically play lower frequencies, making them ideal for two-way front speaker systems. However, a large diaphragm might have some resonance at extremely high frequencies.

Tweeters are made from a variety of materials. Textile domes like silk, metal domes like aluminum, titanium and beryllium and plastic materials like polyetherimide are among the most popular. While the metal versus textile performance discussions will go on forever, what’s more important is that the tweeter diaphragm doesn’t have resonance issues. Most companies add a damping material to the diaphragm to prevent this. The damping applies to both textile and metal designs.

Most tweeters in the car audio market use a dome-shaped diaphragm. However, some use a ring-radiator design, like the tweeters in the Rockford Fosgate T4652-S set. The concept of the ring tweeter is to eliminate the chance of resonance in the center of the dome. While it’s unwise to make blanket statements about one design over others, we were very impressed with the clarity of the T4 ring radiator tweeter.

Flush-Mount Tweeter Installation Options

There are four common options for tweeter installation. First, we have flush-mounting. In this type of installation, the tweeter and a grill are mounted in a panel, and the result is basically flush. This means the tweeter may only protrude a few millimeters or 0.25 inch. This type of installation requires that the panel be modified to accept the tweeter, which means a hole between 1 and 1.5 inches must be created.

The most basic reliable tweeter mounting method uses a U-shaped spring-steel bracket that bolts to the back of the tweeter assembly. The bracket must be spring steel to retain tension and hold the tweeter securely.

Some companies have created more complex installation solutions for flush-mount applications. For example, KICKER’s QS-Series speakers include a nut that threads onto the back of the tweeter to keep it pressed tightly against the mounting surface. The legs of the nut can be trimmed to work with mounting surfaces of different thicknesses.

Rockford Fosgate’s Dual Discrete Clamp mounting solution is one of the most elaborate mounting options we’ve seen. The DDC comprises two cast aluminum brackets sandwiched on either side of a mounting surface to hold the tweeter in place. Once the two clamps are secure, the tweeter locks into place, and a trim piece finishes the installation.

Surface Mounting Options

The second type of installation is to mount the tweeters on the surface of a dash or door panel. This is less invasive as there doesn’t need to be a huge hole cut. That said, holes for wiring or hardware might be required depending on the location. Many tweeters include surface-mounting solutions that position the tweeter parallel to the mounting or at an angle. Angled mounting solutions are helpful when mounting a tweeter off-axis to the listening position. Ideally, a tweeter should be within 15 to 20 degrees of being on-axis with the listener. Alternatively, the tweeter can point at the windshield, dispersing high-frequency information into the listening area.

Tweeter Pods

Another option for installing tweeters is to use pods included with the system. These pods are typically bullet-shaped and mount through a single hole. The design should have a way to conceal the wiring for a neat appearance. You will want to ensure that the pods can be directed at the listening position for maximum performance.

Original Equipment Locations

Most modern vehicles have tweeters integrated into the factory audio system. These are often behind small grilles in the A-pillars, the dash, the doors near the release handle, or the sail panels in the front corner. Often, the factory tweeters are quite small in diameter and overall size. As such, it can be tricky to replace them with aftermarket tweeters. Some companies offer tweeter designs specifically engineered to work in original equipment locations, eschewing grilles and other hardware.

The key to a successful installation in these locations is reliability. We’ll be very clear in stating that mounting with hot glue or butyl rubber is unsatisfactory. These materials can quickly melt when the vehicle interior gets hot in the summer, causing the tweeters to fall out of place. If there aren’t options for mechanical fastening solutions, an epoxy adhesive like 3M Scotch-Weld DP8005 designed to work with plastics is an acceptable alternative.

Custom Installations

Of course, a custom installation solution for your tweeters is always an option. You may want them to blend into the A-pillar, dash or door. You may want a technician to create a custom pod that puts the tweeters in a specific location or points them in a particular direction. You may wish for the installation to look unique. So long as the guidelines about tweeter directivity are heeded, you can have the technician construct almost anything.

The Importance of Proper Tweeter Installation

While a tweeter doesn’t seem like a large item, in the unfortunate event of an accident, the last thing you want is to get hit by a tweeter that’s come out of place. Yes, this is a bit extreme. However, true professionals put significant effort into ensuring that their upgrades to our cars and trucks are safe and reliable. Do you want a tweeter to fall into the door or an A-pillar because it was held in place with hot glue? Certainly not. When shopping for car audio speaker upgrades, drop by a local specialty mobile electronics retailer and ask them which component speaker systems they offer. Be sure to inquire about how they integrate the tweeters into client vehicles.

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.

A while back, we looked at how different subwoofer locations affected system performance in a Hyundai Santa Fe SUV. A client of ours asked if that information was relevant to a sedan. So, let’s take a cool little enclosure and see what happens when we try several different sedan subwoofer locations.

The Test Subject

Our goal in this experiment is to evaluate how the location of a subwoofer in a vehicle affects what we hear. We reached out to Lee Mattason at Burlington Radioactive in Burlington, Ontario. He let us use his 2001 Honda Accord for the test, lent us a subwoofer and provided room in the install bay to do the measurements. We’ve known Lee and his team for over 25 years, and he’s a class act.

We didn’t want the size of the subwoofer to affect the measurements, so the goal was to choose something very compact. Lee had a JL Audio CP108LG-W3v3 8-inch ported MicroSub enclosure in stock. This little monster measures 18.625 inches wide, 11 inches tall and only 5.125 inches deep. The enclosure uses a 8-inch 8W3v3-4 subwoofer. The sub is rated to handle 150 watts of power, and the enclosure’s build quality and finish are exemplary. Honestly, this is a subwoofer solution we’ve been curious about. Will it play low enough for this test? Let’s find out!

The Measurement Configuration

As we’ve seen with other subwoofer enclosure systems designed by manufacturers with extensive experience in the industry, they know how to get the most out of a system by taking advantage of the transfer function of a vehicle. Before doing a complete set of tests, we took a frequency response measurement to ensure that the little woofer was suitable for the application. We set up our Clio Pocket microphone in the front seat and powered the subwoofer with a home audio amplifier. The output level was set to produce a sine sweep referenced to 6.32 volts at 60 hertz. This works out to 10 watts of power into a 4-ohm load. Here’s the first measurement we made with the sub placed in the middle of the trunk.

Um, what? This incredible little subwoofer measures ruler-flat to 10 hertz in the car at an output level of about 100 dB SPL when driven with 10 watts of power. Knowing it can handle 150 watts of power, it can easily produce 110 dB SPL. This is another prime example of expertise in subwoofer enclosure design and an understanding of vehicle acoustics. Sometimes, what looks “right” in a computer simulation might not transfer to in-car performance. There’s no equalization or filtering applied to this. It’s just a signal from the Clio Pocket to a full-range amp. Kudos to JL Audio; this is a little masterpiece!

Measurement Consistency

The graph above shows the subwoofer enclosure frequency response from 10 hertz to 1 kilohertz. We noted that the information below 20 hertz varied significantly during our measurement process. There is a machine shop next door to Burlington Radioactive. Whatever equipment they were using affected this infrasonic range. Sometimes the response was flat; sometimes it had a 10 dB peak at 13 hertz. We know the latter isn’t possible based on our measurement configuration and process. As such, we will leave that data out of the subsequent measurements.

Sedan Subwoofer Location Testing Round 1: The Middle

We started the testing with the enclosure in several locations through the middle of the trunk and facing different directions. The graph above, and as shown in light green in the chart below, shows the subwoofer in the middle of the trunk, standing up on its long side with the subwoofer facing rearward. The medium green trace has the subwoofer facing toward the front of the vehicle. Finally, the dark green trace has the subwoofer lying down on its back, with the driver pointed upward toward the trunk lid.

This graph will serve as a giveaway for what we’ll measure as we continue the testing. The direction doesn’t matter significantly in terms of deep bass, from about 45 hertz and down. The output levels are within a few decibels of each other. What does change is the upper bass performance around the crossover frequency. We’ll leave it at that until the summary at the end.

Round 2: To the Back!

The next three tests will have the little subwoofer enclosure placed at the very rear of the vehicle by the taillights and trunk latch. Once again, we repeated the testing with the subwoofer facing forward toward the front of the vehicle, facing upward toward the trunk lid and facing rearward toward the taillights.

The results mimic what we saw with the enclosure in the middle of the trunk. From about 45 hertz and up, the output is consistent. In this test, the upper bass output changes significantly.

Round 3: Back of Trunk

The next test has the enclosure at the back of the trunk, right up against the rear seats. It’s a long and painful story, but we lost a measurement here, so there are only two. We saw the graph of the subwoofer facing forward in this location, and it wasn’t much different than these two. I know it’s frustrating. It is for us as well. The car isn’t available to repeat the test, or we’d be on it in a flash. Sorry.

These measurements have the light orange line with the sub against the seat back and the driver facing rearward. The darker line shows the sub’s output, with it lying on its back and facing upward.

The conclusion is that there isn’t much difference in output from the various measurements at this location, though up is better than backward. If we recall the measurement with the driver facing forward, it was better in mid-bass output than either. Down low, it was the same.

Round 4: Hide in the Corner

The last location we’ll measure is the right corner of the trunk. We stood the enclosure up on its long side. There are measurements with the driver facing inward toward the vehicle’s center and outward towards the fender. We also flipped the enclosure over so the vent would be facing forward toward the front of the car and at the taillights.

Once again, the direction changes didn’t affect this location’s upper or lower bass output. The last measurement, with the woofer facing the fender and the port directed towards the rear, would be the “best.” However, there is just a few dB SPL variance across all the measurements.

Conclusions on Sedan Subwoofer Locations

In terms of deep bass, below 40 hertz, it doesn’t matter where the enclosure is located. The graph below shows maybe 2 dB SPL of variance across all the tests.

What does change, as we indicated earlier, is mid-bass performance. When installers experiment with different locations, the process likely won’t significantly affect how much bass you hear. The difference is in the mid-bass. The best location is in the corner of the trunk, with the subwoofer pointed outward to the fender and the vent pointed rearward. In contrast, the worst location was with the subwoofer lying flat on the floor at the back of the trunk, with the woofer pointing upward. At 90 hertz, there is more than 20 dB SPL less output. The lack of midbass is typically perceived as the presence of more deep bass. These measurements show otherwise.

If you compete in SPL competitions, this data might not be transferable to that application. At high excursion levels, the vent in an enclosure can be affected by its proximity to nearby surfaces. Moving an enclosure forward or rearward by an inch can yield measurable changes. You’re looking for a peak in the response, not flatness or extension. Different rules altogether.

Yes, different vehicles might present slightly different results. However, our editor-in-chief did this test 21 years ago for another publication and found the same results. Given the variance, we’d ignore that green trace.

When upgrading your car audio system with a subwoofer, the corner of the trunk is an excellent choice. This location keeps the subwoofer out of the way when carrying cargo. It also allows access to the spare tire or a battery that might be stored under the floor. Of course, if you want to run a pair of 12-inch subwoofers, then the back of the trunk will be about the only option. Drop by a local specialty mobile electronics retailer today and ask about adding a subwoofer to your car stereo system. It’s easily one of the best upgrades you can make.

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.