We were recently talking with the owner of a motorcycle audio manufacturer. He mentioned that consumers seem to struggle with the concept that relatively small motorcycle speakers cannot produce large amounts of bass. In this context, a small speaker is something you’d find in the fairing or saddlebag on a motorcycle. By comparison, a large speaker would be an 8- or 10-inch subwoofer. Let’s look at how speakers work to explain why some are good for bass and others are best for midrange applications.

Speaker Design – Subwoofer or Midrange

This article will discuss 6.5-inch speakers, common in cars, trucks, motorcycles and boats. Let’s examine the predicted output response of two popular 6.5-inch speakers. The yellow trace is a JL Audio 6W3v3 subwoofer and the red is a Cicada Audio CX65.4 motorcycle audio midrange driver. We chose these drivers because their Thiele/Small parameters are readily available.

Throughout this article, we’ll unravel a few critical things about this simulation. The response graph you see here isn’t accurate below 100 hertz. Don’t fret; we’ll explain.

Frequency Response Considerations

The first data we want to analyze from the graph is the difference in midrange output. The Cicada Audio speaker (in red) shows good output through most of the audible range. The JL Audio subwoofer starts to roll off its output above 200 hertz.

First, we must clarify a crucial design decision for a speaker that plays a range of frequencies compared with a driver designed exclusively for bass duties. We’ll start with the mass of the woofer cone. The cone must be relatively light for a speaker to respond to signals up to 8 or 10 kHz. A midrange driver might have a moving mass specification of 10 to 15 grams. This would include the cone’s mass, the voice coil former and winding, half of the surround and half of the spider.

The moving mass specification for a subwoofer might be 50 grams. The increased mass adds inertia, making the cone harder to accelerate. The motor (voice coil winding and magnet) won’t be able to move the cone back and forth at high frequencies.

Voice Coil Inductance

The second item that affects high-frequency output is voice coil inductance. We’ve explained that an inductor opposes changes in current flow. For alternating current audio signals, high frequencies change direction thousands of times a second.

A speaker must have a large voice coil to handle large amounts of power. A large voice coil has more inductance and attenuates high-frequency information. The Cicada Audio midrange shown here has a voice coil inductance of 0.03 millihenry. The JL Audio 6W3v3 subwoofer has a voice coil inductance of 1.388 mH. This is logical, given that the winding is at least twice as long and likely has multiple layers.

We Need to Move Air

To reproduce low-frequency information, we need to move a significant amount of air. This means that a speaker needs a considerable amount of cone excursion capability. The Cicada driver, designed primarily for midrange duties, has a voice coil overhand-derived Xmax specification of 4 millimeters. On the other hand, the JL Audio subwoofer has an Xmax specification of 8.89 millimeters.

Let’s multiply those numbers by the effective cone area specification to see how much air the drivers can move. The Cicada can theoretically move 44.8 cubic centimeters of air, while the JL Audio subwoofer can move 107.48, which is 2.4 times as much.

Excursion Limits

Here’s where the frequency response chart above runs into an issue. The graph shows the drivers’ output when fed with 100 watts of power. We must also model the cone excursion behavior to understand a speaker’s suitability for a specific situation.

The yellow trace shows us that the subwoofer cone doesn’t move as much for a given amount of power. This correlates back to its mass. However, the 8.89-millimeter Xmax specification tells us the driver will work fine down to just above 30 hertz at this power level. Below that frequency, there will be physical power handling problems.

The Cicada Audio driver is much more efficient. Much of this efficiency comes from the lower moving mass. This is achieved with a much lighter cone and shorter voice coil. Being limited to 4 millimeters of excursion shows that the driver cannot safely play audio frequencies below 100 Hz at a power level of 100 watts.

A drawback for use in another application often offsets every decision in designing a speaker for a specific application. A tweeter won’t produce bass, and a subwoofer won’t produce high frequencies. Midrange drivers might not make much bass or high-frequency information.

No Transfer Function

Now, specific to a discussion about motorcycle audio and powersports speakers, we’re at a considerable disadvantage compared with a car or truck because we don’t have an enclosed vehicle that offers some gain. The interior of a car or truck provides a significant bass boost. In fact, 20 to 30 dB of boost at frequencies below 30 hertz isn’t uncommon. There’s usually 10 dB of boost at 50 Hz. We call this effect cabin gain.

Even a moderately capable small speaker can reproduce a reasonable amount of low-frequency energy in a vehicle. The same happens in our homes. A single good-quality 12-inch subwoofer with 500 or 600 watts of power in a home theater system can give your couch or chair a good shake. It takes dozens of 15- or 18-inch subwoofers and thousands of watts of power at an outdoor concert to reproduce those frequencies at the same volume level.

We lack this gain when creating an audio system for a boat, motorcycle or side-by-side. This means our small speakers are on their own to produce usable amounts of bass information. If we want to reproduce bass, we need speakers that can move a significant amount of air. We also likely want to hear vocals and instruments.

Our little circle of performance, however, makes this almost impossible. We need a driver with a large motor and cone assembly to move a lot of air. A large motor assembly is heavy. Heavy cones can’t respond to high-frequency information.

What’s the Solution if We Want Bass?

The answer to getting bass on your motorcycle, boat or side-by-side is to add a subwoofer. It’s not going to rumble like the same-size driver in a car, but it will fill in a lot of the information below 150 hertz. Crucially, having a subwoofer means the small speakers don’t need to try to reproduce bass information. They can focus on midrange frequencies, which means they’ll need a lot less power and will sound much better.

Is One of These Speakers Better Than the Other?

Before anyone thinks that the Cicada Audio or JL Audio speaker is better than the other, we’ll make it perfectly clear that each is designed for a different application. Which is better, a snowmobile or a top-fuel dragster? One is likely better than the other if you are in Alaska. It depends on what you’re trying to do.

The reality is that each speaker is designed for a specific application. JL Audio has many high-performance midrange speakers to accompany its subwoofers. Likewise, Cicada Audio has several woofers designed for motorcycle applications. Choosing the right speaker for your needs is the key to creating a mobile audio system that sounds great. Drop by a local specialty mobile enhancement retailer today and ask them for suggestions about speakers for upgrading your vehicle. Let them know your performance goals, and they’ll design a solution that will sound great!

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.

When it comes to getting great sound on your Gold Wing, Harley-Davidson or BMW, the key is to pick the best motorcycle speakers you can afford. The speakers in any audio system are the only link between what you hear and the electronics that play your music. Even the best radio and amplifier in the world would sound mediocre with low-quality speakers. So let’s look at a few criteria for choosing motorcycle speaker upgrades.

Consider Power Handling

Speakers for motorcycle and powersports applications are likely to be played at high volume levels. This is because the audio system needs to overpower wind and exhaust noise while remaining clear. In the case of motorcycle speakers, power handling breaks down into two considerations: thermal capacity and excursion-limited capabilities.

The thermal capacity of a motorcycle speaker depends primarily on the diameter and length of the voice coil, along with any technologies included in the design to allow hot air to circulate. A speaker rated for a lot of power typically has a larger coil and winding. If someone proposes that a speaker with a 0.75-inch voice coil can handle 200 watts of power continuously, you should question the validity of the specification. A speaker with a 1.5-inch voice coil is usually good for about 100 to 120 watts of power.

A more important consideration for motorcycle applications is how far the woofer cone on the speakers can move. A specification called Xmax describes the height of the voice coil winding relative to the size of the magnetic gap. This value is a theoretical limit of the speaker’s linear operation. However, this value doesn’t consider suspension component limitations or non-linearities. When you try to play music with a lot of bass at high volume levels, the woofer can exceed its rated excursion limit and add large amounts of distortion to the audio it produces.

Many motorcycle speaker upgrades feature PA-style speakers that offer excellent efficiency. The problem with these speakers is that their excursion capability is often very limited. A conventional high-quality motorcycle speaker might have a woofer that can move 5 millimeters in each direction. A similarly sized PA speaker might only have 2 millimeters of excursion. If you try to play music with lots of bass and midbass information at high volume levels, the PA speaker will sound terrible. The technician designing, installing and configuring the sound system on your bike needs to apply a high-pass filter at 200 to 300 hertz to a high-efficiency speaker, then add a dedicated woofer or subwoofer to handle midbass frequencies.

Sound Quality and Frequency Response

Another consideration that ties directly into the previous discussion is sound quality. Who would want to pick a speaker that doesn’t offer a smooth and natural frequency response? I’ve been to shows and heard motorcycle audio systems from far away. In these scenarios, picking out bikes with high-quality speakers is easy. Quite simply, they sound good. The voices and instruments sound real, and there isn’t any emphasis or missing information.

When shopping for motorcycle speakers, take along your favorite song on a USB stick and listen to the speakers that the product specialist suggests. Have them crank the volume, then stand back from the display as far as you can. This will let you understand how the speaker behaves when pushed hard. If the midrange sounds unnatural, garbled or distorted, they are likely not the best choice for your bike. A truly well-engineered speaker won’t change clarity or balance as you increase the volume – it should just get louder.

Motorcycle Speakers Must Handle Environmental Conditions

The last consideration for motorcycle speakers is that they will be exposed to myriad environmental conditions. When you’re out on your bike, your speakers are exposed directly to the UV rays from the sun. This exposure can cause plastics and rubber to break down quickly. Look at an old plastic lawn chair or the black trim on an older vehicle. They will be dry and often have a chalky appearance. Old car tires often show cracking, which signifies that the rubber has started to break down.

The speakers you choose for your motorcycle should be constructed with materials designed to resist UV damage. They shouldn’t fade or change colors. Look for speakers that include specific mention of UV-resistant designs. Ideally, the drivers should pass a UV exposure test to confirm that all materials will last.

The second environmental criterion for motorcycle speakers is weatherproofing. The last thing you want is for a speaker to be damaged if you get caught in the rain or splashed while out for a ride. A paper cone would be one of the worst choices for a motorcycle speaker unless it has a tough coating.

You’ll want to look at the speaker’s physical design to ensure that there’s no way for water to get into the motor assembly if it’s a coaxial driver. Coaxial speakers will need to have a flexible secondary joint around the tweeter post, ensuring that it remains watertight. Many companies are selling conventional car audio speakers as motorcycle-specific applications. Taking a few minutes to inspect the driver before making a purchase can save you a lot of headaches down the road.

Quality Speaker Installation Helps Ensure Reliability

Though we will touch on this topic briefly, how the speakers you choose are integrated into your motorcycle’s audio system plays a significant role in their performance and longevity. Unlike a car, motorcycles experience more vibration, which can cause connections to come loose over time. All wiring should be secured so it can’t vibrate relative to an amplifier, speaker or radio. Connections should be a type that won’t harden and crack when exposed to prolonged vibration.

Your new speakers should be mounted securely using corrosion-resistant fasteners. Ideally, the speakers should use existing mounting locations. Please make sure the speakers you choose specify that they have a mounting-hole pattern explicitly designed for upgrading your specific motorcycle.

Picking the Best Motorcycle Speaker Upgrades

The above tips are a good starting point for picking the best-performing, most reliable speaker upgrades for your motorcycle. Another tip is to listen to systems installed on other bikes. Try to listen to the same music on each one and pick out which sounds the clearest and most accurate. When you’re ready, visit a local specialty mobile enhancement retailer that focuses on motorcycle upgrades and start your listening evaluations.

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.

It should come as no surprise that it takes a moderate amount of amplifier power to reproduce music on a motorcycle that’s audible when on the freeway. So aside from great speakers, you need a high-quality amplifier to ensure that you can hear your music. Here are a few considerations when choosing the ideal motorcycle amplifier upgrade.

Amplifier Efficiency is Crucial

One topic often overlooked when choosing an amplifier for a motorcycle is efficiency. In terms of electrical or electronic systems, efficiency describes the ratio of how much power something consumes to how much it delivers. Electric motors, lights and, most importantly for this conversation, amplifiers all have efficiency specifications.

Amplifier efficiency is essential in motorcycle applications because the electrical system is often quite limited compared with that found in a car or a truck. The stock charging system on many motorcycles is limited to around 32 to 38 amps of current. Harley-Davidson offers upgraded alternator solutions that produce between 45 and 60 amps of current. Remember that the ignition system, lights, radio and bike control module are already consuming current. As a gross generalization, amplifiers consume about 10 amps of current for every 100 watts of power they produce. This doesn’t leave much capacity for a high-power audio system. As such, choosing amplifiers that make the most out of the power they consume is crucial.

When looking at amplifier specifications, the numbers are usually presented in one of two ways: efficiency at maximum power or 1/3 or 1/4 power. A good amplifier should have a total efficiency that’s at least 75% to 80% at full power. The best amplifiers on the market are up to around 90% efficient at full power. Sadly, lots of amps are down around 50% to 60%. These inferior products might be rated well, but being power-hungry means they can’t deliver on their claims.

Environmental Protection

A second consideration in choosing an amplifier upgrade for your motorcycle is to look for one designed specifically to resist harsh environmental conditions. For example, vibrations from a lumpy V-twin engine can wreak havoc with electronics that aren’t explicitly designed to handle constant physical oscillations. Likewise, if you use your motorcycle for long rides, the probability of running into rain is high. Therefore, you want to choose an amplifier designed to handle the harshest elements without fear of component damage or corrosion.

Adequate Cooling Capacity

When shopping for a reliable motorcycle amplifier, you want to look for a solution with a large enough heatsink that the amplifier can properly manage whatever heat it produces. Physically larger amplifiers have more heat sink mass, making it easier to extract thermal energy from the power supply and output switching MOSFETs in the amp. As a result, an amplifier that runs cooler will last longer than one built to be as small as possible, with minimal consideration for heat management.

Upgrade Your Motorcycle with an Amplifier Today!

If you want to listen to your music at elevated volume levels, you’ll need a well-designed, reliable amplifier for your motorcycle. Keep the above considerations in mind when you visit a local specialty mobile enhancement retailer to find the best amp for your ride.

Lead-In Image: Thanks to Extreme Audio and Motorrad Audio near Richmond, Virginia, for the photograph of this ARC Audio Moto 720 amplifier that they installed on a 2020 BMW K1600B motorcycle.

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.