Bringing pro-audio high-fidelity features to mobile devices
The future is sounding good for smartphones, tablets and other mobile devices, as a number of technology breakthroughs and new streaming music services are converging to help bring pro audio high fidelity (hi-fi) features to mobile devices. Just as high-definition TV transformed how people viewed television, hi-fi audio is lining up to be the next big thing for portables, especially smartphones.
In fact, there are a number of changes on the way that will improve sound quality for mobile devices. Hi-fi audio features can reduce the effects of noise, distortion or other digital irregularities - such as pre-ringing in your ears - that listeners may not realize are there, but impact their listening experience nonetheless. So let’s have a look at the drivers and enhancements that will, in essence, bring that “vinyl feeling” to your mobile sound quality, without draining your battery.
Where does the groundswell begin?
The first indicators that a move toward hi-fi audio is in the works, is the increase in streaming music subscriptions. According to a MIDiA Research Global Streaming Music Subscribers, December 2016 report, the number of streaming music subscribers more than doubled from 2014 to 2016, from 41 million subscribers to 100 million respectively, and is forecasted to reach 277 million by 2020. In addition, the BuzzAngle 2016 U.S. Music Industry Report noted there were more streams on any given day in the U.S. during 2016 (daily average of 1.2 billion) than there were song downloads for the entire year (734 million.)
The MIDiA data showed that streaming services such as Spotify (43 million subscribers), Tidal (approximately 1 million), Deezer (6.9 million), and Apple Music (20.9 million) are leading the way. Currently, only Tidal and Qobuz are offering hi-fi streaming, while Deezer, Soundcloud and Joox offer partial hi-fi streaming. The big growth is expected to come of course, should big players like Spotify, Apple and Amazon start offering hi-fi streaming. According to SAR Insight & Consulting1 predicts High Resolution Audio (HRA) downloads will increase to 11 percent of the total global market for music downloads by 2020 from only 1 percent in 2016.
Figure 1 SAR Insight & Consulting predicts high-resolution audio downloads to increase to 11 percent of total global music downloads by 2020.
With the early adopters leading the way, these services will awaken users to the vastly different music experience they are missing on their current smartphone devices. But why is there poorer sound quality on a smartphone or other mobile device currently? This has to do with the typical physical constraints in mobile: size, weight and battery life. Until now, the confluence of technical restraints has prohibited cost-effective hi-fi audio on portables, but that is beginning to change.
Bringing pro audio sound to mobile devices
First, what defines “high-fidelity” audio? Simply put, it is low noise and distortion audio that is as close to the original source music as possible. In more technical terms, high-fidelity audio refers to bit rates that allow “lossless” sound transfer. In order to compress the music, the system will “lose” sounds in data bits that it believes the human ear cannot hear, in order to save storage space. However, this “lossy” compression, in say MP3, does result in lower quality audio, because the human ear can actually detect a difference.
This can help explain why the average user “can hear a difference” when listening to compressed music on certain portable devices, but doesn’t know why. There are additional challenges created when bringing hi-fi audio to mobile devices. For example, only now do smartphones have enough storage to keep up with higher-resolution audio. In fact, storage capacity on mobile products has grown exponentially over the last few years, so storing large lossless audio files, such as Free Lossless Audio Codec (FLAC) files, is less of an issue. This means the user doesn’t have to compromise on audio quality just to be able to fit more than a few albums on their phone. Plus, many online music storage companies now allow the user to download, then delete songs and albums easily, eliminating the need to store your entire music collection on your phone.
Audio chip designers are in constant development to try and package high-performance features into tinier and tinier parts. These components are not only becoming smaller, but they are also being engineered to be ultra-low power, in order to maximize battery life. These are just the physical form factor constraints of lightweight smartphones or wearables. Then there are the technical audio design elements that go into play with compressed music and streaming.