When it comes to car audio amplifiers, people often mistake quality with high power ratings. This misperception has led to manufacturers coming up with every angle or trick possible to measure as much power as possible from their designs. Many manufacturers publish both continuous low-distortion specs as well as maximum power ratings. Are the high numbers useful or relevant? Spin up your beanie propeller for a close look.

How Car Audio Amplifier Power Is Measured

There are lots of wrong ways to measure power from a car audio amp. The worst is to make an assumption about the load impedance of a speaker and measure the voltage being produced by the amp. The voltage measurement is used in a simple equation to supposedly calculate power. The problem is, the impedance of a speaker changes depending on the frequency being played, so the math simply doesn’t work.

An ever-so-slightly better method is to use a voltmeter and an ammeter. These tools are used to measure current and voltage. There are two problems with this method. Most users leave both tools in peak-hold mode and perform math on the resulting numbers. As the voice coil of a subwoofer heats up, its impedance rises and current flow decreases. Maximum current will often be present at the beginning of the measurement, then maximum voltage a few seconds later as the current draw from the amp power supply reduces. The second problem is that voltage and current aren’t in phase through a voice coil because the coil has inductance. This gets into somewhat complicated alternating current theory. Just know that the two measurements have to be taken at the exact same instant – much faster than typical meters can produce – for them to be accurate.

During amplifier development, power is measured with a purely resistive load bank and calculated based on voltage. This provides an accurate lab number, but may not translate perfectly into real-world performance when driving highly reactive loads (woofers with high inductance). That said, the numbers are repeatable and consistent.

For real-world measurements, D’Amore Engineering developed the Amp Dyno AD-1. This rack-mount device not only measures current and voltage simultaneously, it also analyzes the audio signal for distortion and can stop the measurement when it reaches 1%. The handheld AMM-1 Audio Multimeter offers the same functionality in a device that can be used with subwoofers and speakers in a vehicle.

What About Distortion?

Determining how much power is available to drive your speakers needs to take into account distortion in the audio signal. If the amp is pushed into clipping, the power it is producing no longer matches the original waveform. Back around 2004, the Consumer Electronics Association (now called the Consumer Technology Association) developed a standard for car audio amplifier power testing called CEA-2006. The standard specifies the supply voltage to the amp (14.4 volts), the load impedance (4 ohms) and the maximum amount of distortion and noise allowed in the output signal (1% THD+N). Manufacturers can include lower-impedance measurements for subwoofer amplifiers designed to produce maximum power into 1- or 2-ohm loads, but they are to be separated from the CEA-2006 (now called CTA-2006) specification.

What About Maximum Power Ratings?

Maximum power ratings, like those provided with most radios, are basically useless. Let’s look at a high-quality multimedia receiver like the Sony XAV-AX5000. Sony rates the radio as capable of producing 20 watts of power from each of the four channels. Total noise and distortion are below 1%, as per the CTA-2006 specification.

If you were to continue to turn up the volume on the radio past the point that the amp reached 1% distortion, the little amplifier IC would keep trying to produce more voltage. The limiting factor is that the amp can only work with the voltage provided by the battery and alternator – about 13.5 to 14.0V in most cases.

This voltage limit means that the most voltage we can apply to a 4-ohm speaker is about 13 volts from the highest peak to the lowest dip.

If we push the output to a level that would contain roughly 1% distortion, the result would look similar to the following waveform.

If you were listening to this, you’d start to hear the waveform turn sour because of the addition of unwanted harmonic content.

If we find a way to continue increasing the signal going into the amp, without increasing the maximum voltage the amp can produce, the waveform starts to look like this:

What Is Power?

When looking at the above three waveforms, the power is calculated by analyzing the area under the curve for each half of the waveform. For a pure sine wave with no distortion, the equation is (Peak-to-Peak voltage x 0.707)^2 / R. For our 13-volt peak-to-peak waveform with a nominal resistance of R=4 (a 4-ohm speaker), that works out to 21.12 watts. As we introduce more clipping, the rest of the waveform increases in amplitude. There isn’t a simple formula to calculate power in a distorted waveform. Once we get to a square wave, where the voltage swings from our maximum positive to our maximum negative limits, the formula is (Peak-to-Peak Voltage)^2 / R. For our example, this is 42.5 watts.

The graph above tells the tale of clean power versus dirty power. Any output signal that falls into the green area should be reproduced accurately and with minimal distortion. Because of the power supply voltage limits of our amplifier IC, we can get more power from the amp, but it will be distorted and sound garbled.

Are Peak Power Ratings of Any Use?

If an amplifier manufacturer wants to publish the largest possible “power” number on an amplifier, and it is capable of producing a square wave output, then the peak power rating should be roughly double that of the RMS, continuous or CTA-2006 compliant rating. Can we use this power to listen to our music? Not really. It sounds terrible. Drop by your local specialty mobile enhancement retailer today and let them help you choose an amplifier that produces the power you want without adding unwanted distortion to the signal.

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.

The number of times a consumer has asked for a set of speakers based on power ratings is incomprehensibly huge. They ask for 300-watt 6×9’s or a 1,000-watt subwoofer without understanding how the power ratings are created. Let’s quickly review what it takes to make a speaker that can handle a lot of power and explain why that may have nothing to do with sound quality and accuracy.

Before we dive in, let’s talk about an analogy. Say you wanted to purchase a car to race around a track. You need something with great handling, excellent balance and smooth power delivery. Would buying a top-fuel dragster than can produce 6,000 horsepower be the right solution? It might be a fun experiment, but it won’t be the fastest way to get around the track. Ponder this as we dive into the discussion.

Speaker Power Handling Specifications

In absolute terms, specifically for subwoofers, power handling specifications determine how much heat the driver can handle without the voice coil and surrounding components failing. Larger voice coils handle more power because there is more surface area. To varying extents, cooling vents integrated into the motor assembly, basket or voice coil former can further improve power handling.

For small speakers, the specs are quite different. For an accurate explanation of speaker power handling specs, check out this article. In short, a midrange driver with a 1-inch voice coil or a tiny, fragile tweeter isn’t going to handle 200 watts of power from an amplifier.

In spite of all this, you can see that there is no correlation between features or designs that improve the performance and accuracy of a speaker and its ability to handle power.

What To Look for in a Good Speaker?

We could (and likely have) written more than a dozen articles on the importance of choosing a high-quality speaker for your car audio upgrade. First and foremost, you need speakers that fit your vehicle. The product specialist at the shop you are buying from can help with this.

Next, you want to choose a speaker that delivers smooth and accurate output. The balance of midbass to midrange to highs should be smooth. There shouldn’t be any emphasis in any region. If you like a little more bass or some extra sizzle from the highs, that’s what the EQ in a digital signal processor is for.

You can consider power handling if you intend to listen to very high volume levels. A set of $65 coaxial speakers aren’t going to take the output of a 150-watts-per-channel amplifier for hours on end.

If you’re shopping for a speaker solution with an integrated tweeter, you can ignore the number of tweeters in the system. A four-way is not necessarily better than a two-way design. We aren’t even going to touch on the five-way speakers we’ve seen.

Finally, if you’re after truly impressive performance, ask about speakers that include performance-enhancing, distortion-reducing technologies like aluminum shorting rings, copper T-yoke caps and flat spiders. The inclusion of these technologies signifies that the manufacturer has put some genuine effort into ensuring that the speaker operates linearly at high drive levels. Speakers with these features often sound much better when pushed hard to play at high volume levels.

Expert Installation Improves Performance

One last consideration before you go shopping: A set of great speakers won’t sound good if they aren’t installed properly. Proper mounting, wiring and signal sourcing are crucial to ensuring that you get the most from your car audio system. Don’t be surprised to learn that it can cost a few hundred dollars to install a set of component speakers properly.

You may want to consider having your doors treated with sound deadening. Deadening serves two purposes when installed properly. It reduces noise transfer into the vehicle so you can hear more of your music. Second, it can improve the performance of your speakers by preventing that sound coming from the back of a speaker from mixing with the sound coming from the front.

Last, and certainly not least, many high-performance speakers aren’t as efficient as the speakers that come with new cars and trucks. Sure, they can handle more power, but they require more power to make them play at higher levels. Adding an amplifier to your audio system may be necessary to achieve the performance level you want.

Circling back our analogy about cars, quality isn’t about the size of the engine and how much power it makes. A truly fast car needs a balance of great handling, braking, comfort and style. When you’re choosing speakers for your car or truck, performance is measured in smooth frequency response and accuracy, not just an ability to play loudly.

Upgrade Your Speakers Today and Ignore Power Ratings

When it’s time to make your car audio system sound better, visit your local specialty mobile enhancement retailer and ask to audition speakers for your vehicle. Choose the ones that sound the most accurate, then have the system fine-tuned once the speakers are installed to deliver the balance you want.

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.

Jeep Wranglers are surprisingly popular vehicles, given their heritage as a wartime tool. They aren’t particularly stylish, and they don’t handle as well as a regular car. These issues aside, they sell like crazy. In 2017, Jeep launched the fourth-generation Wrangler with improved aerodynamics, a larger interior and better fuel economy. Unless you opted for the premium Alpine option, the stereo in these vehicles is disappointing. Fear not valued reader — hope and help are available! Let’s look at the base stereo system and how it can be improved.

Jeep Wrangler Stereo System

The basic sound system in the JL chassis-code Wrangler includes small speakers in the bottom of the dash and the overhead soundbar and a set of even smaller speakers in the top of the dash. It’s somewhat baffling that a manufacturer would choose to shrink the size of the speakers they use, especially when there’s no subwoofer in the system. We know they built custom-vented enclosures for the speakers to optimize their performance, but sometimes bigger is better.

If your Jeep is a Sport S trim level or higher, you at least have the option of upgrading to the Uconnect 4 system with a 7-inch display, Apple CarPlay and Android Auto. These features don’t improve the sound of the audio system, but at least the radio has some good connectivity options.

Step 1 – Upgrade the Front Speakers

The first order of business is to equip the vehicle with appropriately sized speakers. This isn’t an inexpensive upgrade, for several reasons, but it is worth the investment. Metra, a manufacturer of car audio installation accessories, offers a set of replacement speaker pods that allow a 6.5-inch speaker to be installed in the factory location. The pods are reasonably priced at under $100, and you can choose from almost any coaxial or component speaker set available.

The work to install these pods is a bit extensive. The team at Extreme Audio near Richmond, Virginia, let us know that there are about 50 screws and bolts, along with more than a dozen dash parts, that need to come out in order to complete the installation. You’ll want to budget for about three hours of labor for a basic upgrade — and a little more, depending on your plan for the upper dash speaker solution.

For the speaker locations on top of the dash, you have a few options. You could choose to go with a standard set of component speakers and have the tweeters mounted in place of the stock small midrange drivers. The drawback to this implementation is that the majority of the vocals from your music will appear to come from the lower part of the dash. If your budget allows, using a high-quality midrange driver like the Audison AP2, the ARC Audio RS 3.0 or Audiofrog GS25 will bring the voices up to the top of the dash. These options will work best in a system that includes a dedicated amplifier channel for each of the four front speakers.

Of course, there’s always the option of having a custom solution created. These opportunities are where car audio fabrication experts’ skill really shines. Of course, this will cost more, but if you want great sound that rivals high-end home audio systems, it’s worth every penny.

Step 2 – Sound Bar Speaker Upgrade

Depending on your listening preferences, having speakers in the rear of the vehicle may or may not be important. For the JL Wranglers, they have once again chosen to install small speakers in the overhead soundbar. Upgrading these to something larger will improve efficiency and bass performance. A company called SSV Works offers a set of replacement pod covers called the JJT-SAO65. These new covers will accept 6.5-inch speakers.

As always, the option exists to have something custom made for your vehicle.

Step 3 – You Always Need More Power!

If you wanted smoother frequency response, then the speaker upgrade alone should help. If you want more output from the system, then you are going to need to have an amplifier installed. In fact, most upgraded speakers aren’t as efficient as their factory-installed counterparts, so an amp is a definite must-have to bring the Jeep stereo to life.

When it comes to amplifiers, there are really no limits. An ultra-compact amp can be mounted in the dash and provide more than twice as much power as the factory radio could ever dream of. Something larger with more power output capability and better sound quality would fit nicely under a seat without much hassle. Be sure that your installer keeps the amp off the floor – you don’t want it getting wet.

Step 4 – Add a Subwoofer

It could be said that adding a subwoofer might be the best first step in upgrading the sound system in your Jeep Wrangler. Adding a speaker, enclosure and amplifier designed specifically to produce bass means that the small speakers don’t even need to try. They’ll sound better and so will your music.

There are several Wrangler-specific options available, and as always, your local specialty car audio fabricator can build something unique if that’s your preference.

Make Your Jeep Stereo Sound Great Today!

If you are like most Jeep Wrangler owners and aren’t impressed with the audio system in your little off-roader, don’t fret. It can be upgraded. Contact your local specialty mobile enhancement retailer today to find out what options are available to make your music come to life – whether you’re commuting to work or crawling the trails.
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 we can take anything useful away from the 1984 movie “This is Spinal Tap,” we know that “turning it to 11” is for those times when you need your car audio system to play louder than loud. While the concept seems like a lot of fun when your favorite song comes on, playing your stereo beyond its capabilities might not be the best idea. Keep reading to find out why.

What Is the Volume Control?

The volume control on your car radio determines how much of the signal from the source (CD, tuner, Bluetooth or digital media file) is fed to the amplifier. The amplifier doesn’t know what signal it’s getting, but it happily applies a fixed amount of voltage gain to whatever ends up on its input terminals. If we send a tiny signal because the volume control is turned down, we get a tiny amount of sound. If we crank the volume all the way, and if everything in the system is configured properly, we should get the maximum possible power out of the amplifier with minimal distortion.

The caveat here is the assumption that everything in the audio system is configured properly. If the sensitivity on the amp is turned down a bit, then we won’t get full power from the amp. On the other hand, if the gain is turned up too much, the audio signal may be distorted when it leaves the amplifier. This distortion adds a significant amount of high-frequency harmonic information to the audio signal that can overload fragile midrange drivers and tweeters.

How Much Power Do You Need?

Here’s another tricky question with lots of loopholes. Since music is typically very dynamic, the average power level in a musical audio signal is about 25% of the peak power. The speakers in our cars and trucks are, for the most part, only damaged by overheating from too much power. If you match the continuous power rating of your amplifier in a system with a subwoofer to that of your speakers, you are unlikely to damage them. But is that enough power to turn it to 11? Probably not. The speakers can likely handle a little more power and will play a little louder. It’s a slippery slope, though. If you push a higher-power amp to the point of clipping (where it produces a lot of distortion), then you can quickly overpower your speakers. You didn’t think that designing a car audio system was easy, did you?

For most high-quality component speakers rated around 75-100 watts, matching them with a similarly rated amplifier will be adequate. If you have a set of budget-oriented coaxial speakers, you may want to limit the power to 50 or 60 watts.

Why Do Musicians Turn It to 11?

There’s a common and rampant misunderstanding in the car audio industry about the difference between creating music and reproducing music. During the creation process, especially for instruments like the electric guitar, the addition of distortion in controlled amounts can be a desirable upgrade to the process. Distortion, overdrive and fuzz pedals take the audio signals coming out of the guitar and add harmonics at odd and even intervals in varying levels to change the way the instrument sounds. The result is very different from what would be heard with a standard microphone placed close to the guitar strings.

Many guitarists also have favorite amplifiers and speaker cabinets that further tailor the sound to their tastes. It’s not uncommon to see a recording studio equipped with a selection of Orange, Marshall and Fender amps. The use of vacuum tubes in guitar amps is a clear sign that the musicians want to hear more from their amp and speaker combinations that the information contained in the original signal.

When it comes to reproducing music in our homes or in a vehicle, we don’t want to change the harmonic content of the song that’s playing, Yes, we want it loud and we may choose to equalize the system with a little more bass than was heard in the recording studio, but we don’t want to change the sound of the instruments or performers. Using high-quality audio equipment with excellent distortion specifications, combined with premium speakers and proper tuning with a digital signal processor, will ensure that your car stereo can play your music as loudly as you want while staying true to the source.

Take Care of Your Audio System

If you find you are damaging speakers in your car audio system, then it’s time to visit your local specialty mobile enhancement retailer and talk with them about an upgrade. You may need more speakers, proper system configuration or a subwoofer to make the system sound the way you want and play reliably. Let them have a listen to your system and see what they suggest.

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.