One common misconception about speakers is that underpowering them can cause damage. This fallacy is supported by minimum power ratings from several manufacturers, which adds to the confusion. Never fear, we’re here to explain why you simply can’t damage a speaker by providing it with only a little bit of power, and we’ll clarify how this myth originated.

What Damages Speakers?

Other than poking a dust cap or punching a hole in the cone or surround with a screwdriver, only two things will damage a speaker: too much power and too much excursion. Too much power will cause the adhesives that bond the voice coil winding to the voice coil former to fail, subsequently allowing it to unravel and get jammed in the motor. Too much excursion can cause the spider to be damaged or the voice coil former to smash into the backplate and become deformed.

Why Do Speakers Need Power?

If you want to produce sound, you need to send some amount of power to your speakers. How much power you send determines how much sound is produced. More power is fine, up to the physical or thermal limits of the speaker design.

If you feed a speaker with 1 watt of pink noise, it will play pretty loud. Depending on the size and design, a pair of conventional coaxial speakers getting 1 watt of pink noise can easily produce more than 95 dB of output in a typical vehicle. From a theoretical standpoint, an additional watt of power will increase the output to 98 dB, and doubling the power again to 4 watts produces roughly 101 dB. The process continues until the speaker cones can’t move any farther or the driver fails.

Going the other way, those same speakers will provide 92 dB with 0.5 watts of power, and 89 dB with 0.25 watts. With only 0.125 watts you get 86 dB, 0.0625 watts would be 83 dB and 31.25 milliwatts produces 80 db. That’s about the same noise level as a modern sedan cruising at 65 mph. Power and output levels continue to decrease at a logarithmic rate until you simply can’t hear the music. Clearly, less power won’t cause any damage to your speakers.

What About The Myth of Not Having Enough Power?

The myth about not having enough power and damaging speakers is based around what happens when you drive an amplifier into clipping. Let’s say you have a radio with a 20-watt amplifier rated at 1% distortion. You “can” get a lot more power out of that amp, but it will include a LOT of harmonic information. If you were playing a 1 kHz tone at a total output level of 30 watts, you would hear significant 2 kHz, 4 kHz, 8 kHz and 16 kHz energy being produced. This addition of high-frequency energy can strain the thermal capabilities of the tweeters in your system.

If you don’t have a powerful enough amplifier to reach the volume levels you want, you can damage the speakers by feeding them too much high-frequency energy by driving the amplifier into clipping. It’s the extra power in these harmonics that damages speakers.

Choose the Right Amp for Your Speakers

If you’re considering upgrading your car stereo system, visit your local specialist mobile enhancement retailer so you can audition different speakers for your vehicle. Choose speakers with a smooth and accurate response and an amp with excellent noise and distortion specs and that can produce as much power as the speakers are rated for. This combination, when installed and configured properly, will sound amazing and last for years.

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 enjoy cranking your music, the SPL Show Neo speakers from Hertz might be the perfect solution for your car, truck or motorcycle. Designed with ultra-compact, high-flux neodymium magnets, these speaker solutions are capable of delivering rock-concert volume levels to ensure you hear every part of your music loudly and clearly.

More-Powerful New Magnets

The Hertz SPL Show line has been upgraded with new, stronger neodymium magnets. These N38H magnets are rated for high-temperature applications to ensure the speakers will continue to sound great for years, even after prolonged use at high output levels.

Hertz has designed each of the new SPL Show speakers with weather-resistant materials and properties to ensure they can withstand prolonged exposure to rain and the sun’s UV rays. The motor assemblies are treated with a corrosion-resistant electro-coating using a process called cataphoresis.

High-Efficiency Bullet Tweeter

The ST 25A Neo is a compact, high-efficiency, high-frequency compression driver that features an aluminum diaphragm mated to a 1-inch copper-clad aluminum ribbon voice-coil. The unit has a nominal impedance of 4 ohms and an amazing efficiency of 107 dB. The driver is rated to handle 100 watts of power when filtered at 5 kHz with a 12 dB/octave crossover. These same drivers are available in the ST 25K Neo kit version with inline passive crossovers and thread-on metal mesh grilles.

SPL Neo Midrange Drivers

The new Neo line includes 6.5- and 8-inch midrange drivers. Both speakers use a lightweight pressed paper cone that has been treated with a water-repellent coating. Compliance is provided by a double-roll cloth surround and a flat linear spider.

The 6.5-inch SV 165 NEO features a 1.5-inch voice-coil former that is wound to a nominal impedance of 4 ohms. Continuous power handling is rated at 150 watts, with peak power at 400 watts. With a resonant frequency of 120 Hz and an Xmax specification of 1.5 mm, high-pass crossover points around 250 to 300 Hz will ensure maximum output with minimal distortion. Efficiency is specified at 97 dB and the compact neodymium magnet allows for a mounting depth of only 2.25 inches.

The larger 8-inch SV 200 NEO uses a taller 1.5-inch-diameter voice-coil to increase Xmax to 2.7 mm and power handling to 200 watts continuous or 500 watts maximum. Efficiency also jumps to a mind-blowing 100 dB. Mounting depth for the 8-inch driver is a manageable 3.3 inches.

Coaxial High-Efficiency Speaker Solutions

Hertz developed a set of high-output two-way speaker solutions to make upgrading motorcycle audio systems easy, efficient and reliable. The solutions start with the 6.5-inch SX 165 NEO coaxial driver. This two-way speaker features the same weather-treated pressed-paper cone material as the SV 15 NEO. A large-diameter 1.4-inch PEI-dome tweeter provides excellent high-frequency output to beyond 20 kHz. The tweeter is protected with a resettable solid-state protection device to ensure years of reliable operation.

Hertz rates the speaker at being able to handle 100 watts of power when filtered with a high-pass crossover set to 150 Hz at a slope of -12 dB/octave. Peak power handling is 200 watts.

For saddlebag speaker applications on touring bikes, the Hertz SX 690 NEO is a great choice. This 6×9-class speaker features a three-way design with a 0.8-inch super-tweeter and a 1.4-inch tweeter. Both high-frequency drivers use Tetolon dome materials and feature the same resettable protection circuit used on the 6.5-inch driver. A rubber surround at the top edge of the weather-treated pressed-paper cone ensures reliability.

Efficiency is specified at 94 dB and Xmax at 5.5 mm. With lots of excursion capability available from the woofer, the SX 690 Neo can easily play down to 100 Hz or lower, depending on your output expectations. Power handling is listed at 130 watts continuous and 260 watts peak.

Great Sound with Less Weight

One of the key features of the new NEO speakers is their weight. Compared to their ceramic-magnet brethren, they have much less effect on the handling of your motorcycle. For example, pair of SV 165 NEO weighs 3.96 pounds. A pair of the SV 165.1 comes in at 8 pounds. The SV 200 Neo is 5.3 pounds per pair compared to 12.4 pounds for the SV 200.1.

Turn Your Next Drive into a Concert with Hertz SPL Show Neo Speakers

When it comes time to upgrade the sound system on your motorcycle or side-by-side, or the one in your vehicle, if you want the system to play at extreme volume levels, drop by your local Hertz retailer and ask about the new SPL Show Neo speakers. For more information about Hertz products, visit their website. You can follow them on social media by liking their Facebook page, following their Instagram feed and Twitter, or subscribing to their YouTube channel.

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.

Our continuing look at the tools a mobile enhancement technician should have at his or her disposal brings us to the ever-important digital multimeter. In the same way that an RTA or oscilloscope is needed to measure and quantify alternating-current signals, a high-quality multimeter is the only way to accurately quantify a DC or fixed-frequency AC signal. Read on to find out how technicians use their digital multimeters (DMM) to test the wiring in your car to make the installation process more accurate.

What Is a Digital Multimeter?

In essence, a DMM is a battery-powered, handheld device with a digital display that can perform several measurements. A DMM is occasionally (but rarely) called a Volt-Ohm-Milliammeter (VOM), giving us some insight into its capabilities. In almost every case, the meter will have between two and four terminals at the bottom for the connection of the test leads and an LCD or VFD (vacuum fluorescent display) screen at the top of the unit to show the measurement reading. Some of these displays include an analog bar graph that can be used to help detect transient signals. Finally, the function selection is made by a rotary control in the middle of the unit.

Most units will measure direct current (DC) and alternating current (AC) voltages to either detect or quantify the presence of voltage on a terminal or wire. Meters separate the DC and AC measurements into different functions as some math needs to be applied to the AC measurement to create an RMS value. Premium meters known as True-RMS systems are more accurate when measuring AC signals outside of the 50-60Hz frequency region.

Multimeters can also measure resistance. They perform this task by feeding a very small amount of current through a device (resistor or circuit) and measuring the voltage drop across a fixed resistance value. DMMs are good at measuring resistance above an ohm or two and up to about 50 megohms. Below 1 ohm, the resistance of the cables and connections becomes an issue.

Finally, most meters can be used to measure AC and DC flow. The meters have an internal shunt resistor that is wired in series with the circuit. The voltage produced across this shunt resistor is converted to a current flow measurement. The test lead connects for current measurements are different than those for voltage and resistance readings.

How Technicians Use a DMM

When you are having a remote car starter, security system or even a new radio installed in your car or truck, the technician will use a multimeter to test the wires in the dash for the presence of voltage. In almost all cases, the tech needs to find a good ground, a constant power source and a switched (or accessory) source to feed and control the device.

Resistance measurements come in handy when testing speaker wires or terminals on a subwoofer enclosure to estimate the impedance of a speaker. For techs who are installing remote starters on older General Motors vehicles, they use the ohmmeter function to measure the value of the Passlock resistor in the key. It’s worth noting that the ohmmeter in a DMM can’t be used to test the suitability of a ground connection accurately. A proper grounding point should have well under 0.01 ohms of resistance.

Finally, taking current measurements is ideal for troubleshooting situations where car batteries are being drained. If you have a situation where your car battery is dying after a few days, the technician can measure the current being drawn from the battery to start the diagnosis and repair process.

Choose the Right Mobile Enhancement Retailer

As we’ve mentioned in the past, choosing the right person to work on your vehicle is the most important aspect of the upgrade shopping process. A moderate-quality upgrade that has been installed and configured correctly will undoubtedly outperform a premium product that hasn’t been installed with care. When you tour the shop as part of your retailer interview process, make sure they have the tools required to perform the work you need. At the top of that list of tools is a quality digital multimeter.

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.

As we continue our look at how car audio amplifiers work, let’s discuss how the classic Class AB amplifier output stage works and explain why it’s still the benchmark for high-end audio systems.

How Does a Class AB Output Stage Work?

We recently looked at the power supply, the input stage and how Class D output stages work to allow your car audio amplifier to reproduce music. If you go way back to the beginning of high-power car audio amplifiers, you’ll find the Class AB design.

A Class A amplifier uses a single output transistor to add current to the output signal to drive your speaker. When no music is playing, the output device is halfway on and gets very hot. Think of the output as a resistor. If you put two small resistors in series across your power supply, a lot of current would flow through the load. A Class A amp works the same way.

Class B amplifiers use a pair of output devices and split the voltage delivery duties between each device. When no music is playing, both devices are turned off and no voltage is produced at the speaker. The problem with Class B amps, as the guys at BestCarAudio.com discussed in their Class AB Amplifier Distortion article, is that there a dead zone that occurs as the voltage across one of the diodes in the transistor is biased on. The result of not compensating for this roughly 0.7-volt bias requirement is called crossover distortion.

Class AB Amplifier Output Stage

The Class AB amplifier is a Class B amplifier with a small bias voltage applied to the output devices to get them ready to play music. Different amplifier designs use different amounts of biasing to balance between efficiency and silky-smooth operation.

Amazing High-Frequency Extension

One thing that high-end Class AB amplifiers are known for is their extended high-frequency performance. Many top-end amps can play beyond 80 kHz with ruler-flat, low-distortion performance. If you are building an audio system that is compatible with high-resolution audio, this extended high-frequency response is crucial.

Low Output Impedance

As compared to Class D amplifiers that use inductors and capacitors on their outputs, Class AB amplifiers, except in configurations with variable voltage power supplies (often called Class G or Class H designs), don’t need these devices. The result is less variance in output voltage relative to load impedance and more predictable response.

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Efficiency versus Performance

At low to medium power levels, Class AB amps are not as efficient as a Class D amplifiers because the output devices act like resistive voltage dividers across the power supply rail voltages. As such, AB amps need larger heatsinks to ensure their reliable operation. As you approach the upper limits of an AB amplifier’s output capabilities, their efficiency becomes similar to that of a Class D amp. The output devices are close to being all the way on or off.

Experience the Ultimate in Car Audio Amplification

If you are determined to assemble the best possible audio system for your vehicle, visit your local specialist mobile enhancement retailer and ask about using Class AB amplifiers. Yes, you’ll need to find room for them in your vehicle, but the amazing clarity and detail they provide is well worth the effort.

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.