Users are most likely to come across the term “digital signal processing” (DSP) while looking for a new pair of earbuds, home theatre systems or other audio electronics products. Some might think of it as a casual term used for marketing, but DSP is a very complicated subject. Digital signal processing involves taking an audio signal (it can be any signal but in this case it’s audio)and digitally manipulating it to achieve the desired result. It may sound simple, however, the actual processing and the algorithms used can be highly complex. Here we will discuss what DSP means and how it can improve your audio products.
What are digital signal processors?
Whenever you see an audio product like headphones described as having “a DSP,” it means that the device has a built-in digital signal processor. This dedicated chip is used to process audio signals in specific ways. These chips are more common in devices that wouldn’t necessarily have built-in processing prowess, like — headphones and earbuds.
Can DSP be used in devices other than audio products?
Digital signal processing can be used in multiple other devices including — smartphones and computers. Since these devices are already packed with built-in powerful processors, a separate chip dedicated to digital signal processing is often unnecessary. However, DSP-specific chips are often included in systems with traditional CPUs. This happens when audio signal processing has to be done in real-time and the optimised circuits can enhance this type of performance.
How are they used?
Digital signal processing is mainly used for complicated tasks, but it can also perform some simple ones. For example, several audio players use DSP to monitor massive volume jumps between songs, while users are listening to a particular music playlist.
Another common use case for DSPs is analog to digital conversion and vice-versa. The conversion usually happens in specialised DSP chips — known as a DAC or AD/DA converter — that are designed specifically for this purpose. Some of the expensive converters that are available on the market can also transform real-world audio signals into digital signals.
The most important and probably the most common use case of DSP is noise cancellation. Digital signal processing combined with external microphones on the audio device cancels out the noise around the users to improve their audio experience.
Apple uses DSP to do the opposite thing. Transparency Mode, as the tech giant calls this feature, uses the same microphones to amplify the sound instead of cancelling it out, which allows users to hear their surroundings more easily.
Digital signal processing is also used in digital equalisers. Whenever a music app on your phone or computer allows you to adjust the equalisers, it is responsible for digital signal processing. DSP digitally amplifies or lowers the amplitude of certain frequencies as users adjust a slider.
Several modern home theatre systems include a system that automatically adjusts various settings to ensure that the sound is optimised for the size and shape of the user’s room. DSP even sets the timing for each speaker for sound to reach the user in perfect sync.
How important is it for users?
Digital signal processing can turn out to be essential in some cases. Users should pay close attention to certain aspects of the audio products like — the type of digital signal processing or the manufacturer of the DSP chip present inside before buying a device. In the case of headphone amplifiers or A/V receivers, users will experience better sounds if the device has better quality AD/DA converters. However, the difference between the components used in the device will only be noticeable for audio enthusiasts.
The quality of both the DSP chip and the algorithms running on them makes a huge difference in noise cancellation. Not all noise cancellations are equally efficient so users need to pay attention while buying earbuds or headphones. Moreover, if you fancy some novelty features like — onboard EQ in headphones or various sound modes on Bluetooth speakers and A/V receivers you should be well aware of the DSP used inside before making purchasing decisions.
