As we continue our series on headlight bulb upgrades, it’s time to discuss electrical interference. Just as in the previous article on spectral content, this is an issue that very few retailers or manufacturers check for or discuss. While these considerations don’t affect the performance of your lighting system, they can significantly affect the performance of your vehicle’s audio system. They could also potentially affect tire pressure monitoring or keyless entry systems. Let’s dive in!

What Is Electrical Interference?

Let’s talk about what causes electrical interference. At the most fundamental level, any time current flows through a conductor, an electrical field is created around that conductor. We typically discuss direct current (DC) when talking about the battery and alternator in vehicle electrical systems. The fixed electrical field around conductors isn’t a huge issue for DC flow unless the alternator has a regulator problem and is adding alternating current (AC) ripples. Even then, it’s the AC that could pose a problem.

We can get into noise trouble with DC when it powers a device with a switching power supply. Large car audio amplifiers, HID light ballasts and LED light bars are devices with switching power supplies that can cause interference issues. Some LED bulbs also have switching power supplies.

Inside a switching power supply, the DC power from the vehicle’s electrical systems is pulsed on and off very quickly. These pulses enter a transformer that steps the voltage up or down. Amplifiers typically use step-up transformers to produce higher voltages to deliver more power to speakers. Items like LED lighting systems use step-down transformers or buck regulators to decrease voltage.

When the current from the battery pulses on and off, that can create a significant source of electrical interference. If you’ve ever adjusted the dimmer in a home and heard the light bulb ring, that’s the presence of unwanted harmonics caused by switching the AC supply on and off midway through the waveform.

You will find that high-quality amplifiers, in particular, have filtering networks on the power feed into the amp. These networks help smooth any noise that might come from the alternator. Still, they primarily prevent switching noise from inside the amplifier from being fed back onto the power wire to radiate through the vehicle.

What Problems Does Electrical Interference Cause?

In lighting systems, the most common problem in poorly designed lights is the effect on AM and FM radio reception. The noise produced typically occurs in the same range of frequencies as AM (780 to 1610 kHz) and FM (88 to 108 MHz). This unwanted interference can drown out weak radio station signals or add noise to some stations.

Other wireless communication systems like keyless entry and tire pressure monitoring can be affected by sources of electrical noise. Most keyless entry systems operate on 315 and 433 MHz frequencies. Tire pressure monitoring systems use these same frequencies.

If you think a recent lighting or accessory upgrade is affecting radio reception, there’s an easy way to test to see if your hypothesis is correct. Turn on the radio and tune to whatever station you think is affected. Then, turn off the device you think is causing the interference. If it’s a lighting product, turn off the lights. Pull the fuse out of the amp if you think there’s something else, like a subwoofer amplifier, that might be causing problems. This testing process gets tricky if all the sound from your audio system is produced by the amp you think is causing the problem. In that case, seek professional assistance.

Dealing with Electrically Noisy Lighting Upgrades

If you’re in a situation where you have a noisy lighting upgrade, return it and have the shop install a higher-quality product.

If you’re determined to have the shop fight with what you’ve purchased, two solutions typically work to reduce noise feeding back into the vehicle’s electrical system. The first and most straightforward solution is to add an inline filter. These filters include capacitors and inductors that help smooth out the noise from the switching power supply in the lights.

If the installer reads the instructions for most HID and LED upgrades, they’ll note that most reputable companies recommend installing new light wiring. Companies like Lumens HPL offer harnesses with the correct connectors or plugs to integrate directly with the factory wiring. These harnesses include relays, fuse holders and everything needed to power the new lights directly from the battery.

There are two benefits to using a dedicated power harness. First and foremost, power for whatever lights you’ve chosen comes directly from the battery and alternator. These power sources bypass any daytime running light or sensing circuitry, so you know the system will get all the voltage possible from the vehicle. Second, if the bulbs you’ve chosen are from a no-name brand that does cause electrical interference on the wiring, the battery acts like a giant filter. The wiring that might have noise on it remains up in the front of the vehicle. If your installer used the factory wiring, that noise might feed back to a body control module in the vehicle interior.

Measuring Electrical Interference

We have a device in the BestCarAudio.com lab called an RTL-SDR. In short, it’s a USB-stick radio receiver. We can tune into radio frequencies and decode AM or FM audio signals using dedicated software. We can also monitor ham or GRMS radio. This device is a receiver-only solution – we can’t broadcast.

We set the antenna up about a meter from an old HID ballast and took some measurements. We don’t have any low-quality light upgrades around the shop, but at least we could see “something” from our testing.

The image below is a spectrographic capture of 10 seconds of RF energy between 90.4 and 92.9 MHz. These frequencies would be down near the bottom of the FM radio band. Brighter colors in the spectrograph show more power. The red and yellow information on the left is the audio from 91.1 FM. The light blue in the middle is 91.7, and the yellow is 92.1. You can see the clearly defined bands on either side of the 92.1 MHz audio information. Those digital side-bands can carry information like HD Radio or RDS-TMC traffic information.

We moved the antenna to an area of the lab where radio reception is much worse to establish a baseline for our test. That image is below.

Next, we turned on that HID light and repeated the measurement.

Though it’s not terrible, several dozen bands of sweeping energy have now polluted the measurement. These signals wouldn’t likely be strong enough to prevent you from picking up a radio station. Still, it would reduce audio signal clarity when reception is affected by buildings or environmental conditions.

Buy Quality Products and Avoid Headaches

When the price of a product seems too good to be true, it often is. Sometimes, it’s not the specific performance of a light or amplifier; they might do what they claim. However, other factors like electrical interference or heat may cause problems. If you stick with brand-name solutions, you’re unlikely to run into problems. Drop by a local specialty mobile enhancement retailer to learn about the high-quality lighting upgrades available to help you see safely when the sun sets.

Lead-In Image: Credit to @zirconicusso for the radio image used in the Lead-In.

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.

We’ve watched hundreds of videos on YouTube and read dozens of articles on headlight upgrades, yet we’ve never seen anybody discuss how different bulb types light up different colored objects. We aren’t discussing the headlight bulbs’ brightness or the beam pattern. Halogen, HID and LED bulbs output different wavelengths of energy. We see objects when that energy reflects off them and bounces back to our eyes. It stands to reason that the perfect light source would illuminate all colors identically. However, that isn’t the case. Let’s dive in.

Light Source Spectral Analysis

Let’s start with an analogy. Most of our readers are familiar with the audible frequency range of human hearing, which is 20 Hz to 20 kHz. There are plenty of frequencies above 20 kHz that animals like dogs, cats, dolphins, bats and whales can detect. A porpoise can hear from 75 Hz to 150 kHz. That’s a half-octave higher than bats.

Our vision works in the same way. Our eyes can detect light within a specific range of frequencies, between 400 and 790 terahertz. Different frequencies represent different colors. As we age, our ability to detect differences in violet, blue and green objects diminishes.

The chart above shows the colors the human eye can perceive, including frequency ranges and wavelengths. When we discuss color, we use wavelength rather than frequency. Energy with a higher frequency than violet light is called ultraviolet. Energy with a lower frequency than red light is called infrared. Some animals can see energy in these extended frequency ranges to help them find food or mates.

How Sunlight Affects Color Distribution

We can measure the amount of each frequency a light produces using a color spectrometer. The information the spectrometer provides is like a real-time analyzer for audio signals. It tells you what frequencies (or wavelengths) are present and the amplitude of each of those frequencies.

The graph above shows that there isn’t much information below 125 Hz, which is logical since the sample came from a laptop speaker. Because this is a sample of music and not a test tone, there isn’t much else we can extract from the data other than the information extending to 20 kHz.

Now, let’s establish a standard for light spectral measurement. The graph below shows the spectral content of a measurement of the sun taken on a clear day.

We can see that the light distribution is relatively even across the visible spectrum. Environmental factors like moisture, oxygen, dust and pollution cause dips and low-wavelength attenuation.

How we perceive objects depends on the light source that illuminates those objects. All colors are easily visible when we are outside on a sunny day. When we move indoors and use different light sources, the energy balance shifts dramatically. Let’s look at three popular headlight types and analyze how they produce light.

Up first, let’s look at a halogen headlight bulb. This is a basic Phillips bulb with a single filament. It doesn’t have any blue coatings. We measured the light level at a distance of 2 meters from a projector-style headlight assembly.

It’s easy to see that most of the light energy produced by the halogen bulb is in the high wavelength/lower frequency range. This energy distribution makes sense, given the amount of heat the bulb produces. This halogen bulb produces very little green or violet light.

Now, let’s check out the light produced by a high-intensity discharge (HID) light bulb. This particular system is from a company called Lumens. I’ve used them in almost all my vehicles for decades.

The HID bulb produces light that contains peaks at several lower wavelengths. Those peaks would correlate to the different chemicals present in the ARC chamber. Using gas chromatography, scientists can analyze the light from burning gases to identify the elements that are present. The takeaway from the HID analysis is that very little orange or red light is produced.

Let’s look at an aftermarket light-emitting diode (LED) bulb. This is one of the Sportline bulbs from Lumens.

The LED bulb produces primarily blue light with a bit of light green, yellow and light orange. Very little violet, dark blue or red light is produced.

Let’s combine all three measurements to see how they compare in terms of the colors of light energy they produce.

The HID and halogen are similar if you measure the total light produced by these bulbs. The LED isn’t quite as bright in this application. However, we want to look at the frequencies produced by each light source. These correlate to the color of objects that will be illuminated well. If a bulb doesn’t produce a significant amount of red light, red objects won’t show up well.

How Light Sources Affect Object Perception

We set up some Hot Wheels cars on a white background to quantify how these light sources illuminate different colored objects. We took pictures of the vehicles with the three light sources without changing the camera settings. The camera is a Canon 70D with a 50mm F/1.8 lens. The settings for the images are 1/10 of a second exposure with an f/8 aperture and the camera set to ISO 100. Aside from cropping and resizing, we didn’t adjust the images in any way.

The room lights cast reasonably even light over the cars. The dark violet Batmobile to the left of the two-tone blue SUV is a little dark, as these are LED lights. The vehicles are not in the direct hot spot of the light source since we didn’t want too much reflection.

Let’s start with the halogen headlight first.

The violet Batmobile and blue SUV look almost black in this image. The red car on the right and the fluorescent yellow truck beside it are well-illuminated. Of course, the white car second from the left is also easy to see.

Next is the HID headlight.

The two-tone blue SUV appears much brighter in this image. The red on the far-right car and the yellow on the Lego car beside it are much more subdued than with the halogen light source.

Finally, let’s look at the LED bulb.

Unsurprisingly, the green car stands out more under the LED light. The red, yellow and violet cars remain relatively dark.

Now, let’s combine the three images. I boosted the exposure levels in Adobe Photoshop so the overall brightness is similar in each sample.

It’s easy to discern that the ability to see objects depends significantly on the spectral content of light sources and not just their measured lux or rated lumens. A halogen or HID bulb would be best if you wanted the highest-performance lighting system. The worst choice for even light distribution would be an LED bulb. This testing shows that many people underestimate the performance of those old-fashioned halogen bulbs.

Different Lights Illuminate Differently Colored Objects

I was in a vehicle with halogen headlights a few weeks ago while it was dark out. It was clear that those headlights did a much better job illuminating stop and yellow warning street signs than my car with factory-installed HID bulbs. I wouldn’t have described the headlights as bright, but they were surprisingly effective.

If you’re considering a headlight bulb upgrade, remember that the type of bulb you choose will significantly affect what you can see. How bright the bulb is might be less critical. Drop by a specialty mobile enhancement retailer today to find out about the light upgrades that are available for your vehicle.

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.

We are back with the third article in our series about headlight bulb upgrades. In the first article, we discussed the many different headlight bulb designs and how they’ve advanced over the last century. The second article in the series explained the terminology used when discussing light sources. How a light assembly projects light onto the road is more important than the choice of the headlight bulb. If it’s aimed in the wrong direction or with emphasis in the wrong area, you won’t be able to see where you are going. Worse, less-than-ideal light distribution may endanger oncoming drivers. In this third article, let’s review headlight beam patterns.

What Is a Headlight Beam Pattern?

Let’s define the term beam pattern. When you shine a light on a surface, it produces a shape. If the light is a point source like a candle, the light is distributed evenly from the source in the form of a sphere. Bringing the candle up close to a surface will result in a round shape that is brightest, where the light source is closest to the surface. The illumination level decreases as the distance between the surface and the light source increases. Out of a headlight assembly, a halogen or HID headlight bulb effectively acts like a point-source light source.

The results differ if we have a directional light source, like a flashlight. The beam pattern would be a circle on the wall with a sharp cutoff at the edges. The light emanates from the flashlight in the shape of a cone.

Automotive headlamp assemblies are similar to a flashlight. They use a reflector to point the light forward from the front of the vehicle. As forward lighting became brighter, the importance of not blinding oncoming drivers increased. By definition, glare is a harsh, uncomfortably bright light. In the context of our discussion about automotive lighting, glare refers to being subjected to unwanted bright light, typically from another vehicle. An oncoming vehicle’s improperly adjusted lighting system is an excellent example of unwanted glare.

Glare is hazardous as it causes the iris in your eyes to narrow and let in less light. After a vehicle passes you, it takes some time for your iris to open again, making it very difficult to see. Likewise, the bright oncoming light source will drown out darker objects in your peripheral vision. Many advanced driver training courses will suggest that a driver close one eye as a vehicle approaches at night, then open it when the vehicle passes. This process leaves you with one eye ready to see in the dark while the other readjusts. If you’ve seen the movie “Jack Reacher” with Tom Cruise and Robert Duvall, the scene just before the shootout at the mine begins is an example of this technique.

Modern Automotive Headlight Design

Look at the beam pattern when you drive your car up to a wall or garage door. You’ll quickly realize engineers designed the light to illuminate the road in front of your vehicle without blinding oncoming drivers. What you see will look very different from the flashlight image earlier in this article. Most projector-style headlights have a metal shield between the lens and the reflector that blocks some of the light output. This shield produces a sharp cutoff at the top of the light beam pattern.

It’s logical to think that you could use a simple light that’s aimed lower and avoid all the fancy beam-shaping reflectors and shields. The problem with this configuration is that it puts the brightest part of the light, a location called the hot spot, much closer to your vehicle. You don’t want or need much light in the 20 to 60 feet immediately in front of your car or truck. You want most of the light from your headlights focused beyond 300 feet. This configuration will help provide even lighting in front of the vehicle, especially where the cutoff stops illuminating the road.

Driving Beams and High Beams

So far, we’ve only discussed regular low-beam or driving-beam lighting. Switching on your high beams is quite different. The high beams on your vehicle are nearly identical to a flashlight. They project a cone of light that allows you to see much farther down the road. They typically don’t have a cutoff of any kind.

Modern vehicles typically have three different designs for high-beam lighting. Some use secondary light assemblies with dedicated bulbs. Others use a light bulb with two separate filaments. Finally, many projector-style lights have a cutoff that moves out of the way when the high beams are activated. The shield is driven by a small solenoid when the high beams are activated.

Analyzing Beam Patterns

We set up a projector assembly from a headlight and loaded three different bulbs into it. We took photos of each bulb to compare the beam patterns and light output. We started with a halogen bulb, switched to HID, and finally to two LED bulbs.

As a reminder, we’re analyzing beam patterns and not brightness. That said, in our analysis we must consider where the light energy is the brightest.

All images were taken with a Canon 70D camera using an EF-S 10-22mm F/3.5-4.5 USM lens set to its narrowest 22-mm setting. Exposure was 1/80 of a second with an f-stop of 8 and the camera ISO set to 100. No brightness adjustments were made in post-processing, only cropping.

Starting with the halogen bulb, we can see a very bright hot spot in the middle, just to the right of the cutoff. This brightness pattern works well in illuminating objects several hundred feet ahead of the vehicle. The light output to the sides of the hot spot is reasonable. This lateral lighting would help illuminate objects on the sides of the road or as you’re turning a corner. Light output decreases quickly at the bottom of the pattern. This foreground performance helps prevent a bright spot immediately in front of the vehicle.

Moving to the HID bulb, we see a larger diameter hot spot in the middle of the image. This light distribution pattern isn’t as ideal as the halogen bulb. The horizontal performance with the HID is good. You can see some slight unwanted reflections above the cutoff, but they aren’t bad. Finally, the foreground performance looks to be similar to that of the halogen.

Next, we have the ATOM LED bulb in this projector application. This bulb has less of a hot spot, so the light distribution appears relatively even through the illuminated area. One benefit is this LED bulb is that the cutoff is very abrupt. There is little to no light above the cutoff so that oncoming drivers won’t experience as much glare.

Finally, we have the Lumens Sportline bulb. This bulb has a large hot spot in the middle and maintains the sharp cutoff of the ATOM bulb. This bulb puts much more light on the road than the ATOM but is a bit bright in the foreground.

The halogen and HID bulbs significantly outperform the LED bulbs in this application. Keep in mind that this is a specific projector assembly. Further, our research shows that it’s not the highest-quality design available. A differently shaped projector or a reflector-style lighting assembly would likely produce very different results. The takeaway is that your installer needs to experiment with different options to ensure that you get a genuine upgrade for your light bulb investment, not just a different color bulb.

Dangerous Beam Patterns

It’s often difficult to know what to look for in a beam pattern without knowing when something is wrong. Here are some random examples of undesirable headlight beam patterns we found online.

A quick analysis of the above image shows several issues with the left-side headlight of this BMW 330i. There is a dark spot in the middle of the pattern. The lack of light in the center would dramatically reduce long-distance visibility. There is also too much light at the very bottom of the pattern. Too much light down low illuminates the area immediately in front of the vehicle too much. The result is another reduction in long-distance visibility. The left headlight is also aimed higher than the right. Improper aiming results in blinding oncoming drivers or poor long-distance visibility.

Based on a quick analysis of the above image, someone has likely installed incorrect bulbs in this Subaru Outback or clocked them incorrectly. There is a poor cutoff, minimal lateral light distribution and far too much light in the foreground. Given the distance to the garage door, we’d also predict that the right-side headlight is aimed much too far to the left. Driving with a lighting system that performs like this could be very dangerous.

Though the actual light pattern from this 2014 Lexus ES isn’t bad, the headlights need proper aiming. The right headlight is probably aimed too high. The rectangles above the cutoff are intentional and illuminate street signs.

North American and European Lighting Standards

The guidelines for automotive headlights differ significantly between Europe and North America. If you look at the light patterns we’ve shown, there is a clear step in the middle of the pattern. The left side is lower than the right. This pattern provides better road illumination in the front of the vehicle with less chance of blinding an oncoming car or truck. In Europe, rather than a step, the cutoff is at an angle that extends to the edge of the assembly. This pattern illuminates more of the road and increases light to the right-side shoulder. This design would work better to light up road signs.

Proper Forward Lighting Is Crucial to Safe Night Driving

If you’ve changed or upgraded your headlights or are planning to, this article explains the importance of choosing headlight bulbs or light assemblies that work correctly. A high-output bulb in an incorrect application can drastically reduce how well you can see. Work with a specialty mobile enhancement retailer to pick only the best solutions for your application. Improving nighttime visibility may require testing different bulb options in your vehicle. We’ll discuss light color and brightness in our next article.

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.

We talked about headlight bulb styles in the first part of our series on understanding headlight upgrades. In this article, we will briefly explain relevant light terminology to help you understand what lumens, lux, candela and watts mean. Knowing what these terms mean will help you make better bulb upgrade choices – and you’ll be less likely to be fooled by bogus light output claims.

The Importance of Proper Headlights

The forward lighting system on your car or truck is, or at least should be, designed to light up the road in front of your vehicle. The lighting should be bright enough to allow you to see and react to objects in your path safely. If your car needs two seconds to stop from 40 miles per hour, then your lights need to illuminate objects at least 117 feet in front of your vehicle.

The Candela

Long ago, a light source’s output was comparable to the light produced by a typical wax candle. A conventional wax candle produces 1 candela (symbol: cd) of light. It’s crucial to understand that this is the total light output of the light source in all directions. Put another way, no matter what direction you’re looking at a candle from, it produces 1 candela or 1 cd.

Light Terminology – Lumens

A lumen (symbol: lm) is the most commonly used descriptor of how much light a bulb produces. The lumen is the SI unit used to quantify luminous flux. Sadly, it’s also easy for this number to be irrelevant in describing how well you can see in front of you at night.

We have to detour a moment to make a super-technical definition. The term steradian, or square radian, describes a circular area on the surface of a sphere. A sphere (or ball) has a surface area of 4π steradians – or 12.5664 steradians. Expressed another way, 1 steradian is 1/12.5664 of the surface of a sphere. If you have a sphere with a radius of 2 meters, then 1 steradian represents 4 square meters on the surface of that sphere. It should be no surprise, then, that the total surface area of the sphere is 50.265 square meters and that 1/12.5664 of that is 4 square meters.

OK, now back to the lumen. One lumen equals 1 steradian of a sphere illuminated by a light source that outputs 1 candela. Think of this description as that of a flashlight pointing at the inside of a sphere. If the flashlight produces 1 candela of output and all the light is focused onto an area the size of 1 steradian, the result is 1 lumen of illumination.

If we back up and consider the light source to be isotropic or equal in output in all directions, then the light source must produce 12.5664 candelas to produce 1 lumen of flux over an area of 1 steradian. In theory, you need about 12 and a half candles to produce 1 lumen of luminous flux on an area of 1 steradian of a sphere with a radius of 1 meter. A 1-candela light source would produce 1/12.5664 of a lumen on the same area, or 0.0796 lumen.

When professional light bulb manufacturers measure a light source’s output, they use an integrating sphere. The inside of the sphere has a pure white reflective coating. The goal of the sphere is to average out any bright or dim spots to create an even distribution of light through the assembly. A calibrated electronic sensor measures the light level in the sphere to calculate the total light provided by the light source.

When a company like Cree or Samsung creates an LED, they describe the output of the LED COB in lumens, or more accurately, lumens per watt (LPW). A high-quality LED COB produces about 133 lumens of output per watt. Most high-power LED COBs have a maximum power handling of about 3 watts. This efficiency means a 1-watt single LED COB can produce about 400 lumens. An aftermarket LED headlight bulb that uses one of these LED COBs on each side would produce 800 lumens. Compact assemblies with three or four COBs assembled into a single housing are available. These 12-watt LED COBs produce about 1,500 lumens. If a 12-watt COB is on each side of the bulb, it would theoretically produce 3,000 lumens.

Light Terminology – Lux

Unfortunately, having an incredibly bright light bulb doesn’t directly correlate to proper road lighting. Understanding lighting terminology is crucial. The plastic lens on the front of the light assembly blocks a small amount of light. The design of the reflector at the back of the light assembly plays a considerable role in determining where that light projects. In a worst-case example, you could have a 3,000-lumen headlight bulb in a black box, and no light would be visible and, as such, the bulb would produce 0 lux.

Lux (symbol: lx) is the SI unit of luminous flux per unit area. The lux is the unit that quantifies light intensity as the human eye perceives it. Thankfully, unlike the whole steradian thing (sorry about that), the lux uses an area of 1 square meter. One lux equals the illumination of 1 lumen of light over 1 square meter. If all the light from a 100-lumen light source illuminates 1 square meter, the light intensity would be 100 lux.

How do all these numbers relate to headlight bulb ratings and how well you can see the road once the sun sets? With modern LED headlights like you’d find on an Audi, Mercedes-Benz or Genesis, the optics are designed to work specifically with the LED COBs light emission pattern. Every aspect of the light source is optimized to produce a specific beam pattern on the road. If you upgrade your headlights from a halogen bulb, HID or LED aftermarket bulbs must work with the existing reflectors and lens. The upper cut-off for the low beams must be accurate, and the light distribution pattern needs to remain the same. These criteria are crucial for your safety and the safety of those you share the road with.

Companies such as Rigid Industries and Baja Designs that manufacture aftermarket off-road and work light solutions provide light output levels in lux. Both companies describe the distance from the light where they produce a fixed illumination level. Of course, the two companies don’t use the same descriptions, so you have to do some “figurin’” to determine which is best for your application.

Watts, Power and Light Output

The SI unit watt describes the work done over a fixed time – usually one second. One amp of current flowing through 1 ohm of resistance in electrical circuits produces 1 watt of heat energy. To calculate watts in direct current (DC) circuits, you can multiply the voltage times the current. If you apply 12 volts to a light bulb and 2 amps of current flow through the circuit, then the work done is 24 watts.

When all we had were halogen bulbs, a bulb that drew more energy would typically produce more light. The low beams on most cars and trucks used 35-watt bulbs, and many used 55-watt bulbs for the high beams. Unfortunately, those numbers don’t correspond to light output regarding HID and LED replacement bulbs. A 15-watt LED bulb produces significantly more light than a 35-watt halogen bulb. Many HID kits were marketed with 35- or 55-watt ratings, making three or four times as much light as halogen units. The bottom line is that looking at HID or LED headlight upgrades and comparing them by the energy they consume won’t be effective.

Research Your Headlight Upgrades

A forward lighting system that functions accurately and reliably is the top vehicle safety consideration once the sun sets. If your headlight bulbs are worn out, the lenses are foggy, or the lights aren’t aimed properly, your risk of getting into an accident increases dramatically. Now that you understand automotive headlight terminology better, you can make better purchasing decisions. Drop by a local specialty mobile enhancement retailer today to find out about the upgrades they have available to improve the lighting system on your vehicle.

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.

If you pay attention, you’ll see cars and trucks on the road with white, yellow, blue and even purple headlight bulbs. Whether chosen for style or performance, hundreds, if not thousands, of options are available to upgrade the lighting on your car, truck or motorcycle. Some replacement bulbs look neat, some are brighter, some have unwanted side effects, and some perform poorly. Let’s kick off this series about automotive headlight technologies and upgrades with some history and a look at the different lighting designs used on vehicles.

Headlight Bulb Styles

If you’ve been around the block a few times, you know there are two basic types of headlight bulbs: sealed beam and composite light assemblies. Sealed-beam bulbs were introduced around 1940, providing automakers with a relatively high-performance, all-glass lighting assembly that included the bulb, reflector and lens in a single non-serviceable unit. The vehicle manufacturer only needed a secure mounting and alignment solution to deliver reliable lighting. Some quick research shows that the 2017 Chevrolet Express van was one of the last newly manufactured vehicles to use sealed-beam headlights.

Around 1983, the first composite headlight assemblies began to be implemented in new cars and trucks. These lighting assemblies use three injection-molded plastic pieces to serve as the body, reflector and lens. These lights are typically molded in shapes that flow with the vehicle’s contours. One instant benefit of these designs was that automobile manufacturers could improve vehicle aerodynamics and allow more leeway in vehicle styling.

Composite light assemblies have replaceable bulbs that fit into a unit that includes a body, a reflector and a lens. When the bulb fails, it is removable from inside the engine compartment, often with minimal difficulty. The cool-for-its-time 1984 Lincoln Mark VII is believed to be the first production vehicle to use composite lighting.

The composite headlight evolved to include a dedicated projector assembly within the lighting fixture. There are claims that the projector assembly, which consists of a reflector, lens and often a cutoff shield or shutter, provides more efficient light output than a reflector-style. It’s probable, but the specific performance comes down to the engineer who designed the light.

Headlight Technologies

Whether the vehicle has sealed-beam or composite lights, there are dozens of bulb shapes and sizes. Sealed-beam bulbs came in various round and square sizes. Some bulbs had both low- and high-beam filaments in the same assembly. Bulbs for composite lights are similar, though much more compact. These bulbs are also available with single or low/high designs in one assembly.

Many composite light assemblies have a single bulb with a single light source that handles low- and high-beam conditions. When you want to see farther down the road, you pull back on the light control stalk on the left side of the steering column, activating an electromechanical solenoid in the projector. The solenoid moves the shutter out of the way, allowing all the light from the bulb to illuminate the road.

The Evolution of Automotive Headlight Bulbs

Headlights have come a long way from oil lamps burning in large housings on the front of the vehicle in 1880. Though electric lights started becoming popular in homes around this same time, it wasn’t until after 1910 that electric lights on vehicles became popular. These “higher-performance” light sources quickly became a requirement for new vehicles.

Early incandescent headlamp bulb technologies didn’t differ much from the lights some vehicles still come with today. In an incandescent light bulb, a filament made from tungsten is enclosed in an airtight glass chamber. When electricity passes through the filament, it heats up and produces light.

The next evolution was the halogen incandescent light bulb. According to several sources, halogen headlamps were developed in 1961 by a group of European light bulb and headlamp makers. Halogen lamps use the same filament design as a conventional incandescent bulb but have a small amount of a halogen gas like iodine or bromine added to the chamber. Adding these chemicals results in the filament burning brighter and producing a whiter light. It also resulted in a bulb design that lasted significantly longer than its simple incandescent counterparts.

Interestingly, these bulbs weren’t initially permitted in the United States as they were too bright and exceeded the government’s 37,500-candela output limit. In Europe, headlights could have an output of 140,000 candelas per side. The light output limit in the United States was raised to 75,000 per side in 1979. An extremely detailed outline for lighting requirements and limitations can be found in Federal Motor Vehicle Safety Standard (FMVSS) 108. If you ever want to geek out or have a thorough understanding of the laws that govern all vehicle lights, give FMVSS 108 a read.

The next evolution in lighting technology was the high-intensity discharge (HID) bulb. Rather than applying the direct battery voltage to a filament, HID lighting systems have an external ballast module that feeds high-voltage, high-frequency energy to a pair of tungsten electrodes enclosed in a glass chamber. The chamber is filled with a noble gas and a metal or metal salt. Light is produced as the voltage jumps from one electrode to another, like a welder’s arc. This type of light source is often called an arc lamp.

The benefits of HID bulbs include a whiter light than incandescent or halogen bulbs and a more efficient system. Xenon arc lamps are a specific kind of HID system that uses xenon gas in the bulb. Other chemicals like mercury vapor, metal halide and sodium vapor are common in commercial applications such as high-bay lighting, theatre and movie lighting, and film projectors. There are even HID lamps that use radioactive isotopes like thorium and krypton-85 to help make the arc initiation easier. Bulbs for automotive applications do not use these radioactive materials.

A potential drawback of HID lamps is radio frequency interference. The high-output voltage of the ballast that drives the bulb (which can be over 400 volts) combined with a high switching frequency that can exceed 100 kHz can produce harmonic information that can affect both AM and FM radio reception. Many less-expensive aftermarket HID upgrade kits have this interference problem.

Light emitting diode (LED) headlights are another newer technology that has provided several options to vehicle manufacturers. LEDs are solid-state semiconductors that emit light photons as electrons flow through the device. Early LEDs were expensive, costing hundreds of dollars per lumen of light output. Improvements and advancements in materials, production quantity and design have evolved so that LEDs now cost hundredths of a cent per lumen.

An important benefit of LED lighting technology is that it’s quite efficient. These lights are also incredibly compact and last tens of thousands of hours. LED lights reach their maximum output level almost instantly, whereas halogen bulbs take a part of a second, and HID bulbs can take several seconds. This instant illumination makes LEDs ideal for turn signals and brake lights where every millisecond matters in an emergency. Studies have shown that LEDs can save more than a tenth of a second in warning other drivers. When moving at 65 miles per hour, one-tenth of a second represents a distance of 9.53 feet. That’s significant. The compact size of LEDs allows automakers to get creative with styling, as the space needed to produce adequate light output on the road is minimal.

While LEDs are efficient, they are small and remain sensitive to heat. You will note that LED lighting assemblies include large heatsinks to ensure that the individual LED chips don’t overheat.

A drawback of aftermarket LED bulbs is that they haven’t historically been able to place the light source in the same location as an incandescent or HID bulb because of the need for the heatsink. This limitation can reduce the effective light output of the assembly because the reflector or projector optics might not be optimized properly. The only way to know if an aftermarket LED bulb will work in your vehicle is to test it before purchasing.

It’s worth noting that the little orange or yellow LED chip you see on each side of an aftermarket LED bulb is an array of multiple LED elements. These are called chip on board LEDs, or more commonly, an LED COB. A single COB includes dozens of individual LEDs mounted on a thermally efficient substrate and covered by a phosphor coating designed to produce a specific light color.

The latest technology in automotive lighting is lasers. Companies like Audi, BMW and Mercedes-Benz offer laser-equipped high beams on several vehicles. These lights use a solid-state laser diode to shoot an intense blue light at a yellow phosphor. The phosphor is similar to the yellow rectangles you see in LED lights. Reflectors and lenses can then direct the output of this light source to illuminate the road.

The benefit of laser light solutions is that they are even more compact and energy-efficient than LEDs. Production vehicles first implemented laser headlights in 2014. Laser high beams can illuminate up to 600 meters in front of a car or SUV. Because of the intensity of the laser light sources, active light control technologies help ensure that oncoming drivers aren’t blinded.

Light Brightness and Other Lies

Just as with incredibly overstated amplifier and speaker power ratings, the aftermarket lighting industry has fallen prey to completely bogus light output claims. I can tell you with the utmost confidence that a single 9005 LED bulb with two chips will not produce 22,000 lumens of light output.

To understand the math behind the above statement, a state-of-the-art LED COB can produce about 400 lumens of light with 1.6 amps of current. LED intensity is controlled by how much current flows through the device. So, to produce 22,000 lumens of light, the bulb would need to draw 88 amps of current.

The specifications provided with these so-called 22,000-lumen LED bulbs note that they use 80 watts. At 12 volts, that’s 6.67 amps of current. A more appropriate light output claim would be about 1,670 lumens if they used the highest-performing LED COBs available. Oh, one last note: Many aftermarket LED bulb manufacturers quote the light output from the pair of bulbs. So, the “bogus factor” can be divided in half and still be impossible. As always, buyer beware, and don’t believe everything you read.

Last and certainly not least, upgrading your headlight bulbs is not a free-for-all. As with audio system upgrades, enthusiasts often think they know more than the engineers who designed the factory-installed systems. Longevity, legal compliance and thermal management are key considerations when designing a lighting system. We’ve seen many examples of high-output aftermarket headlight bulbs melting reflectors and lenses. We suggest the “better solutions” approach rather than the “brute force” approach to improving forward lighting.

Up next in this series, we’ll examine aspects of lighting like lumens, candelas, lux, watts, color and temperature.

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.