What is an audio processor (DSP)?

An audio processor, also known as a DSP (Digital Signal Processor), is a device used to process and optimise the audio signal in a sound system.

A DSP gives you considerably more control over the sound than a conventional car stereo. Among other things, you can determine which frequencies each speaker plays, adjust sound levels and tailor the soundstage to the car’s cabin.

A DSP is particularly useful because speakers in a car are often at different distances from the listener, affecting how the sound is perceived.

What can you do with a DSP?

Crossover filters: Determine which frequencies are sent to the tweeters, midrange drivers, midbass drivers and subwoofer.
Time alignment: Delay the sound from certain speakers so that the sound from the different drivers reaches the listener more nearly at the same time.
Equaliser (EQ): Adjust different frequency ranges to create a more balanced sound.
Level adjustment: Adjust the sound level for each speaker or channel.
Signal routing: Determine which input signals are sent to each output.
Phase adjustment: On models supporting this feature, adjust the phase to improve the interaction between different speakers.

Can I use a DSP with the car’s factory stereo?
Yes, many audio processors can be connected to the car’s factory stereo via high-level inputs.

This makes it possible to upgrade the sound system without replacing the car’s existing stereo or infotainment system.

In some cars, the factory signal may already be filtered or processed. It is then important to choose a DSP that can handle the signal correctly.

Do I need a DSP to improve my car audio?
Not necessarily. Many aftermarket stereos already have basic audio adjustment features, such as an equaliser and crossover filters.

A separate DSP is especially worth considering if you want to:

Build a more advanced sound system with several speakers and amplifiers.
Keep the car’s factory stereo but improve sound quality.
Control each speaker individually using active crossovers.
Optimise the soundstage with more precise time alignment and EQ.
Gain better control over signals, filters and levels in a powerful sound system.

Is it difficult to set up a DSP?
A DSP offers many possibilities, but it needs to be set up correctly to achieve a good result.

The most important thing is to start with the correct signal and channel settings, then adjust crossover filters and levels before fine-tuning time alignment and EQ.

Incorrect settings can worsen sound quality and, in some cases, damage the speakers.

At BRL Electronics, you can get help choosing an audio processor, as well as professional installation and audio tuning.

For more detail, we recommend our guide DSP in the car: from signal to finished sound, which covers the entire process from connection to final audio tuning.