What Is DSP Audio

This article will discuss what is meant by DSP in so far as it relates to audio.

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It will also discuss what DSP is and how it works in many applications from telecommunications to car audio.

Ever wondered what DSP audio is and how it can help you to achieve better sound quality in your applications

Well, keep reading if you want to know why and what to do about it.

So what is DSP Audio?

DSP stands for the digital signal processor. A digital signal processor processes a digital signal into a different digital signal resulting in improved audio quality.
In layman’s terms, a DSP device takes in a signal, modifies it, and produces a better, more tuned signal, which is then sent to for example an aftermarket amplifier, so you can get quality sound.

My name is Paul Smith, I am an audio and film enthusiast with over 10 years of experience in reviewing and writing about audio-related products and content.

I have looked at how DSP works and its various applications and would love to help you understand it too.

Below I will cover the following topics in relation to what DSP audio is.

Understanding DSP
What’s Inside a DSP
Where is Digital Signal Processing Used
Types of Digital Signal Processors
What is DSP in-car audio?
What is DSP on a speaker?
Is DSP better than crossover?
What is DSP in music?

1. Understanding DSP

A DSP can be a stand-alone unit or be part of an amplifier or speaker unit

DSP can be used to add delay to ensure sound bounces evenly between your speakers, specifying which frequencies of your music go to the tweeter, woofer, and sub.

DSP can be used as an equalizer for your room, so sounds sound as if they are coming from the correct place and at the correct quality irrespective of the room size.

DSP can be a wide range of algorithms and can include such things as cross-over frequencies/cross-over points/ques/stereo widening algorithms.

DSP also encompasses all tools that speaker engineers need to make a high-performance audio system.

From a technical perspective. With Digital Signal Processors (DSP) real-world signals like voice, audio, video, temperature, pressure, or position that have been digitized are mathematically manipulated.

A DSP performs mathematical functions like “add”, “subtract”, “multiply” and “divide” very quickly.

2. What’s Inside a DSP

Program Memory

Saves the programs used by the DSP to process data. The program memory stores the programs needed for data to be translated.

Input and Output

Represents the interface to the real world and other devices and appliances. Input and output in DSP essentially serve a range of functions to connect to the outside world.

This is where analog signals are changed to digital, processed, and then converted back to the analog domain so as to interact once with headset users.

DSP chip/computer engine

The engine of a DSP system. This chip performs all calls and contains all the algorithms to make it work.

Compute Engine

Performs the math processing, accessing the program from the Program Memory and the data from the Data Memory.

Input/Output

Serves a range of functions to connect to the outside world

3. Where is Digital Signal Processing Used

DSP can be used in areas and industries such as telecommunication, car audio, and high-end electronics.

In the car, audio DSP can enhance the audio quality of your speaker’s system so you get clearer more accurate, and even louder sound.

DSP is used in telecommunications to achieve voice enhancement and noise suppression.

Other areas of DSP usage include, speech processing, RADAR, seismology, audio, SONAR, voice recognition, and some financial signals.

For example, Digital Signal Processing is used for speech compression and transmission for mobile phones.

In high-end headset equipment, DSP is used to protect users from hearing damage.

Other applications include Mp3 file manipulation, CAT scans, computer graphics, MRI, and even amplifiers for certain electric guitars.

4. Types of Digital Signal Processors

Automatic Gain Control

Next, the DSP system automates and balances the volume throughout a conference, so that the signal never gets too loud or too quiet.

This can dramatically reduce audio fatigue.

A/D D/A Conversion

Allows users to connect microphones directly into a DSP appliance, without needing a separate device.

A DSP converts analog signals to digital data, processes data, and converts it back to analog without affecting audio quality.

Acoustic Echo Cancellation (AEC)

Prevents unwanted echoes. Echo cancellation prevents your voice from being amplified on the other party’s system and then gets played back again on your speakers.

AEC subtracts that audio from the microphone’s signal before any echo can occur.

5. What is DSP in car audio?

With respect to car audio systems, DSP allows you to control the cross-overs, time alignment, and the equalization of all of the speakers and subwoofers in the system.

The DSP, therefore, allows you to fully tune a system to achieve the best possible sound.

6. What is DSP on a speaker?

This would be where a DSP is included in an embedded speaker system Often embedded systems require the speaker to go into a device, such as a grill/baffle/cavity.

These are acoustical compromises. The DSP reduces the peaks, boosts the dips created by the acoustical compromises, and recreates that flat frequency response.

There are a few types of digital signal processors

7. Is DSP better than crossover?

If you can set cross-over on a DSP why would you have passive cross-over?

This is a question many people ask.

There is a presumption that DSP is newer technology and passive cross-over is older technology

A passive cross-over becomes useful when you have more speakers than channels on your amplifier

This is done to protect the speakers, for example, you could damage your tweeters if you played bass frequencies through them.

This is also done to optimize the system as each speaker excels at playing at different frequencies.

For example, if you have a 5 channel amplifier

This would be the case if you have a 4-channel amp for speakers and a subwoofer amplifier for the subwoofer – which means a total of 5 channels of amplification.

Then suppose you have a 7-channel speaker system with

2 larger speakers to play midrange speakers – front component speaker for the left door

2 Tweeters to play high frequencies – front component speakers for your right door

2 – 6×9’s and a subwoofer

The objective of introducing passive cross-over is to limit the frequencies of sound playing through each of the speakers.

What you can do is take the first channel out of the amplifier and place it into the passive crossover.

You can then take the 2 outputs out of the cross-over which can go into the woofer and the tweeter.

The cross-over will limit the bandwidth of information going to each speaker

That means you have used 2 amplifier channels to power 4 speakers and the rest to power the 6x9s and the subwoofer.

8. What is DSP in music?

DSP in music provides important functions during mixing such as filtering, signal addition and subtraction, signal editing, and artificial reverberation.

Music is typically recorded on multiple channels or tracks.

This can involve recording individual instruments and singers separately so as to ensure that the sound engineer has better flexibility in creating the final mix. This is called mix down

Therefore with artificial reverberation DSP allows artificial echoes and reverberation to be added during mix-down to simulate various ideal listening environments.

Echoes with delays of a few hundred milliseconds give the impression of cathedral-like locations.

Adding echoes with delays of 10-20 milliseconds provides the perception of more modest size listening rooms.

The Bottom Line

Check this video out for a step-by-step guide on What DSP audio is and how it works

As DSP is widely used in-car audio. If you would like to get additional content related to car audio, then click on the links below to check out additional articles.