Smartphone Audio Technology Guide for Music Lovers

It is good news for music lovers that new smartphones are coming with latest new technologies to give better sound quality.

In a smartphone, digital to analog converter (DAC) hardware chips are used converting digital signals to analog. The music we have heard over the years, on vinyl records or cassettes, came from an analogue source. CDs and MP3 marked a shift to digital formats. Every phone has different DAC hardware. That is why the sound may vary even if you’re using the same app, music file, earphones or speakers. Some phones have a dedicated DAC chip, while others rely on the chip integrated with the rest of the processing hardware. If you are looking for a smartphone with great audio, look for one with a dedicated DAC chip.

Some examples of dedicated DAC hardware include the ES9218 Quad DAC in the LG V20, which has a built-in headphone amplifier to negate the audio-detailing loss during transmission. Similarly, the Samsung Galaxy Note 5 has the Wolfson DAC. 

However, two phones with the same audio chip don’t always have the same level of audio output either. How well a phone maker optimizes the audio chip’s software algorithm plays an important role.

Qualcomm Aqstic audio codec

While some phones use the audio codecs that come by default with the processing hardware, phones that are positioned for music lovers tend to use the overlay of better-tuned codecs. For example, phones based on the Qualcomm Snapdragon 820, such as Xiaomi Mi5 and HTC 10, take advantage of the Qualcomm Aqstic audio codec that supports up to 192-kHz/24-bit playback. The Qualcomm codec also comes with an Aqstic smart PA (power amplifier), which boosts the audio output in the phone’s speakers.

Codecs are designed to decode the data across different file formats and, over the years, the focus has been on keeping file sizes as small as possible without sacrificing quality. 

Hi-res Audio

Hi-res audio is a popular term for higher-quality audio formats, and codecs such as

·   ALAC (Apple Lossless Audio Codec)

ALAC is developed by apple supported on iPhone, most iPods, Mac and iTunes. ALAC is data compression method which reduces size of audio files with no loss of information. 

Decoded ALAC stream is bit-for-bit identical to the original uncompressed audio file.

·   DSD (Direct Digital Stream) 

DSD Records is the trademark used by Sony and Philips for their system of digitally recreating audible signals for the Super Audio CD ( SACD ).

DSD uses Pulse-Density Modulation Encoding - a technology to store audio signals on digital storage media that are used for the SACD.

·   MQA (Master Quality Authenticated) 

MQA is an audio codec using lossy compression and a form of file fingerprinting, intended for high fidelity digital audio internet streaming and file download. 

Launched in 2014 by Meridian Audio, it is now owned and licensed by MQA Ltd.

They offer better audio quality but at the cost of larger file size since it wouldn’t be compressed as much. 

Marshall London and LeEco Le Max 2 support these audio formats.  

Dolby Atmos

Uses head-related transfer functions (HRTF) to process binaural sound emanating from a particular point. For example, if a user is watching an action movie or a game with lots of gunshots, smartphones powered by Dolby Atmos will be better equipped to tell which side of the screen a gunshot was fired from. 

The Dolby Atmos feature has been used by phone makers such as Lenovo, HTC and LG.

CDLA (Continual Digital Lossless Audio)

LeEco’s CDLA (Continual Digital Lossless Audio) technology works with unique headphones that the company ships with its phones. In a traditional 3.5mm jack-based set-up, the decoder is located in a smartphone and the headphone itself just delivers sound. LeEco has moved the audio-processing chip to the headphone. This reduces audio-detailing loss and enables a more wholesome listening experience. 

Incidentally, LeEco was the first phone maker to do this; Apple and Motorola, among others, have followed. 

FLAC file (Free Lossless Audio Codec)

Very few users are musicians, audio engineers or connoisseurs of sound . Recorded audio takes up about a few 100 MBs. If MP3-like conversion didn’t exist, not more than one album could be carried on an average smartphone.

But when a song is converted, or rather compressed – from a lossless file to something much smaller in size – like an MP3, it loses information. The strumming of a guitar would sound exactly like it was recorded, for example, when you listen to lossless audio on a FLAC player; but dull out comparatively on a phone playing MP3 file.

Good headphones are also required to hear good quality music.

Wireless headphones are growing in popularity, especially for use with smartphones. The absence of wires does add an element of convenience. But with most kinds of Bluetooth implementation, there will be some loss of quality in wireless streaming, compared to wired audio playback. If you don’t really need the convenience of wireless, wired is still a better bet.