When it comes to ways to control the volume and tracking or seeking on a car radio, the three most popular options are rotary volume controls, pushbuttons and touchscreen interfaces. While many buyers focus on features like Bluetooth, Apple CarPlay, Android Auto and backup cameras when shopping, there’s more to consider. A key and often overlooked part of the process of choosing a new radio for your vehicle is to try the model you have in mind on a display board at a local specialty mobile enhancement retailer. Can you adjust the volume without having to look at the radio? Is it easy to change songs or radio stations? Can you change sources while keeping your eyes on the road? A radio that looks great but is difficult to use won’t be enjoyable – or safe.

What Is a Human-Machine Interface?

Whether it’s a car radio, a microwave oven or a computer, the controls we use to change settings or provide input to an electronic device make up a human-machine interface. Companies devote thousands of hours to developing what these interfaces look like and how they work. Some are incredibly intuitive, while others can be frustrating.

The first popular smartphone was the Blackberry. These compact devices had miniature keyboards that made entering text quick and easy. Later, companies shifted to touchscreens for a sleeker look. Many Blackberry users resisted the transition because there wasn’t any tactile feedback. You could enter two or three characters on a touchscreen without even knowing, while the pressure required to register a character on a mechanical keyboard was very distinct.

Classic Car Radio Control Options

If we think back to the ’60s and ’70s, car radios typically had two knobs: The left knob was the volume control, and the right one adjusted the tuner. No matter what car you got into, you already knew how to use the radio. These radios used analog potentiometers (variable resistors) for volume control functions. Even the DIN-and-a-half radios from Delco and Chrysler kept this same straightforward approach to adjusting the volume. An excellent interface is one that we can use without having to think about how it operates.

Rotary Volume Control Radios

In a single-DIN receiver, most modern solutions include a rotary volume control on the left side of the chassis. The analog potentiometer has been replaced with a digital encoder that sends commands to the microcontroller that manages all the radio functions. Likewise, on many models, this control also has an integrated pushbutton that allows you to change sources or access balance, fader, bass and treble controls.

On double-DIN radios, the availability of a rotary volume control depends on the size of the display. If you have chosen a radio with a 6.2- or 6.4-inch touchscreen, then there is likely room for a small volume control on the left side of the radio. This may be paired with a source button and additional buttons for track selection or preset adjustment.

The advantage of this design is that you can adjust the volume without having to take your eyes off the road. By reaching over to the radio, you intuitively know how to use the three buttons by feel.

Pushbutton Radio Controls

If you opt for a double-DIN multimedia receiver with a 6.95- or 7-inch display, then you’ll find they use a set of pushbuttons for volume adjustment. Depending on the size and placement of the buttons, this can still be a relatively intuitive solution. Look for units with separate physical buttons as opposed to smooth membrane switches.

Very few single-DIN CD and digital media receivers use pushbuttons for volume control.

A drawback of pushbutton volume controls is that they don’t let you adjust the volume quite as quickly as a rotary control. That said, most radio manufacturers include programming that increases or decreases the volume relatively quickly if you hold the corresponding button for about a second.

Membrane and Touch-Panel Controls

Though they may look sleek, the membrane switches or touch panels that let you make adjustments to your audio system are difficult to use while driving. If you want to change sources, adjust the volume or change tracks, you have to look at the radio, then press the corresponding area of the screen. Sure, the process may only take one second, but if you are driving on the highway, that means you’ve traveled about 100 feet. A lot can happen in that time.

Steering Wheel Audio Controls

Most cars come with buttons on the steering wheel that will let you adjust the radio volume, change tracks or change media sources. In almost every case, your installer can integrate these buttons into an aftermarket radio using a small computer module called a steering wheel control interface. Once it’s configured, you can make adjustments safely while you monitor your driving.

Some of the more capable interfaces allow your installation technician to configure multiple functions to work with a single button on your steering wheel. For example, your installer could program the interface to activate the voice recognition mode of CarPlay or Android Auto if you press and hold the Source button on the steering wheel for two seconds.

Test Your Radio Before Buying

As you can see, there are many options available to control your new car radio. Before you make a purchase, test the radio you have in mind on a display board at your local mobile enhancement retailer or in one of their demo vehicles. If you can’t make basic adjustments safely, then it might be worth looking at a different solution.

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.

There are two reasons why we’d want to upgrade the speakers in our vehicle: the original speakers may be damaged, or we want to improve the clarity of the audio system. In either case, you’re going to need to visit a local mobile enhancement retailer and choose a speaker solution that fits your vehicle, works with your budget and sounds great. This will involve auditioning several options before you make a purchase. Not listening to speakers before buying them would be like trying to pick out a suit or choose a new paint color for your car while blindfolded.

Choose the Right Music

The first step in auditioning speakers is to choose the right music. You’ll want to pick something that you know well and have listened to on a variety of audio systems. You should listen to these songs, or portions of them, as much as you can before you go shopping.

It’s best to choose tracks that highlight certain aspects of a speaker’s performance. For example, a song with a solo vocalist is a good way to evaluate midrange tonal balance. Smooth response through the midrange is crucial as our hearing is very sensitive to these frequencies. Even subtle changes in midrange response are easy to detect.

You will want a track that demonstrates the overall tonal balance of the speaker. If we are looking at a coaxial or component speaker, then choosing a solution with energy from the midbass, midrange and high-frequency range is essential.

Where a great speaker separates itself from the mediocre is in its dynamic performance. There’s no such thing as a fast speaker. The ability of a speaker to respond to a transient signal is determined by its frequency response. What you want to evaluate is how fast the speaker settles after the signal is removed. Tracks with percussion, bass guitar or an upright bass are great for this. Does the speaker respond to a floor tom with a snap, or is it sloppy with lots of resonance? Does the pluck or strum of a string resonate clearly, or does it get shrouded in harmonic content?

Control All the Variables

When you go speaker shopping for your car, truck, motorcycle or boat, it’s likely that you’ll be listening to a display in a store. You’ll want to try to listen to music at the same volume level on every speaker you audition. Increasing the volume, even by a small amount, will make background sounds seem louder and more present. Higher volumes can also excite resonances in the room that will make it seem like a speaker is producing more bass.

Where the challenge of matching the output of one speaker to another gets exasperating is that it’s rare to find two different speakers with the same efficiency. Try as hard as possible to make things equal.

You’ll want to make sure there isn’t any equalization applied to the speaker. The tone controls on the source unit should be set flat. Some higher-end displays may include a digital signal processor. In these cases, ask whether each speaker solution has been matched to the same reference frequency response curve and target efficiency. If so, this is an ideal way to compare the performance of different speakers.

Consider System Design

If your car audio system will include a subwoofer, then how you audition a set of coaxial or component speakers will change. You should ask that a high-pass filter be applied to the speaker so that it’s not trying to make bass. In fact, you’ll find that speakers that seem to produce a little less midbass are often more accurate than ones that produce more.

Loudness or emphasis within a narrow band of frequencies is not an indication of quality. It’s usually a sign of unwanted distortion or poor design. Check out our article on Speaker Q for more information on this topic.

If you’ll be using the speakers without a subwoofer, then bass output matters. You may choose to trade some accuracy in the midbass region for more output. It’s a worthy sacrifice to make the system enjoyable.

What Will the Speakers Sound Like in My Car?

The problem with auditioning speakers in a showroom is that unless they have been equalized with a DSP to a specific target curve, you’ll hear something different once they are installed in the car. What you’re looking for isn’t the absolute response of the speaker, but the performance characteristics of the driver and how they differ from the other options. Your job is to pick out the speaker that sounds as accurate as possible. A speaker that is bright on the display may be annoyingly harsh in a vehicle. Likewise, one that produces a lot of midbass may sound very boomy or sloppy. If the speaker is neutral and accurate, then it’s likely to be a well-designed solution that will sound great.

Listen, Listen and Listen

When it’s time to shop for new speakers, audition as many options as is reasonable. Learn to pick out the performance differences between the options. You can start this process at home with a home stereo, a portable Bluetooth speaker and your smartphone and some headphones. Very quickly, you’ll be able to pick out a speaker that sounds right. Once it’s in your vehicle, you can have the technician tune the system to deliver the frequency response you enjoy.

Put a few songs you know well on a USB memory stick and head to your local specialty mobile enhancement retailer today. Auditioning new speakers can be a lot of fun and very educational. Done correctly, it ensures that your audio system will sound the best it can.

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 upgrading a car audio system with a digital signal processor, you’ll typically hear about a discussion of signal delay. Maybe people refer to this as time alignment or setting the delays. No matter what term is used, understanding the benefits and drawbacks of this technology is crucial to creating a car audio system that sounds amazing.

Let’s Talk About Stereo

Three crucial factors are required to recreate a coherent and accurate stereo imaging from a sound system. First, the frequency response of the left and right speakers needs to be the same. If there are differences, sounds that are louder in one channel will appear to move toward that corresponding speaker. Second, and this is an extension of the first, the volume level of both speakers needs to be the same. Finally, and most relevant to our discussion of delay, the sound from each speaker needs to arrive at the listening position simultaneously.

In a home audio system, we can move our chair or change seats on the couch to place ourselves in a position that’s equidistant from each speaker. If the speakers are similar distances to the rear and side walls, then their frequency response should be similar. The result is a listening experience where sounds appear to emanate from the space between those speakers. We call the plane from which the sounds come from the soundstage. The accuracy with which each performer and instrument are rendered on the soundstage is described as imaging. Better imaging means that each voice or instrument is rendered with more precision and detail, making the sounds seem more realistic. If a recording captured the reflections in the room, then an audio system with good staging and imaging can reproduce those sounds and provide a sense of space.

What Is Signal Delay?

If we are sitting between two speakers, then the distances to each speaker are equal. The problem is, we are talking about car audio systems. When we’re driving, we sit on the left side of the vehicle, which puts us much closer to the left-side speakers. This results in those speakers seeming louder than the right-side drivers and, crucial to this discussion, we hear sounds from the left speakers before those coming from the right.

In terms of our soundstage, when the perceived output level of the speakers is different, and we hear one speaker long before the other, the soundstage will be compressed into the very left side of the vehicle. This doesn’t sound very realistic.

Even modestly priced car audio DSPs and many premium radios have the ability to add delay to the output of one or more channels. Through various configuration and calibration methods, these adjustments add delay to the signals going to speakers in your audio system. Let’s say you have a simple three-way system with tweeters in the sail panels, woofers in the doors, and a subwoofer in the trunk. You will hear the left tweeter before any other speaker because it’s the one closest to you. Next, you’ll hear the left woofer. This is followed by the right tweeter, then the right woofer, and finally, the subwoofer. Uncalibrated, you end up with a blurry, unfocused mess. When the technician calibrating your processors adds delays to all the speakers, the sound from each arrives at the listening position simultaneously.

Speaker Delay Settings

Getting the delay settings correct is not only important to make it seem as though we are sitting exactly between the speakers, but it also affects the frequency response of the audio system. If there are effective pathlength differences between the left and right speakers, some sounds will add constructively, and some will add destructively. This frequency response issue is called comb filtering, and it’s nearly impossible to EQ out of a system.

Inexpensive to moderately priced processors usually have delay adjustments with a resolution of 0.02 milliseconds. That means each step is about 6.8 millimeters or about 0.27 of an inch. Newer processors that use higher sampling rates of 96 kHz can cut those numbers in half. Don’t get hung up on the resolution of the delay setting when purchasing a DSP – it’s more important to set them all properly than to have a little extra resolution.

Let’s Talk About Two-Seat Systems

As you can imagine, setting the delays to each speaker in our hypothetical three-way system will, when combined with proper speaker placement and equalization, result in an audio system that sounds amazing. That great sound, however, is only heard in one seat – the driver’s seat. Your passenger will hear almost all of the music coming from the right edge of the vehicle. We call this a one-seat tune.

Audio systems designed to deliver balanced sound from all positions in the vehicle require a different approach. Your installer will need to implement all-pass filters to tame the comb filtering. Ideally, the vehicle should use a processor with an upmixer that extracts mono information from the left and right channels and feeds it to a dedicated center speaker. To my knowledge, there’s only one DSP currently on the market with this type of upmixer.

Upgrade your Car Audio System with a Digital Signal Processor

Without a DSP, your technician can use an equalizer or level controls to try to balance the perceived output of the speakers in your vehicle. While this helps create a center image, the focus will be mediocre, and the sounds that are left and right of center will be compressed, stretched and likely blurry. When you add a DSP with a stereo equalizer and signal delay capabilities, then have the system calibrated by a trained professional, your music will sound like you are sitting in your living with natural balance and fantastic realism. Drop by your local specialty mobile enhancement retailer today to audition a digital signal processor and have them upgrade your car audio system.

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.