Pertaining to audio, aptX is
advertised as the means of achieving CD quality sound, wirelessly! What is
AptX? Get to start to understand aptX, you’ll need to know how digital audio
works.
Digital audio is a compilation of
audio signals encoded in a digital format that can be used to record, store,
generate, and/or reproduce sound. As CNET so eloquently explains, a sample of
the collection shows what a sound wave looks like at a specific moment, like a
freeze frame. With enough of these freeze frames put together these frames can
be converted back into a smooth sound wave by a device designed for digital
playback. CD-quality refers to rate of 16 bit/44kHz which accounts for 44,100
samples every second and where each sample has a value between 0 and
65,535 (referred to as "16-bit").
Digital playback devices can play
16 bit/44kHz though this rate isn’t easily streamed via web or say wireless
device as it’s about 10MB in size. MP3 files are much smaller (at about 1MB)
and easier to stream because they are compressed. Bluetooth is a global
wireless communication standard that allows for the easy exchange of data over
short distances. Translation, only so much data can be transferred at one time
down the tiny Bluetooth pipeline. Wi-Fi would allot for much more. So
if you’re sporting over ear Bluetooth headphones but want to hear the best in audio quality, your
device is going to need some help.
This is where aptX comes into play.
It is a codec algorithm that compresses the digital audio signal by removing
parts of the audio that aren’t noticeable by the listener and cause the least
amount of impact on the fidelity of the audio.
AptX Director of Sales and
Marketing, Johnny McClintock explained more to LifeWire, “AptX runs at 354 kilobits per second, and it’s a fixed
4:1 compression ratio so the performance is guaranteed… SBC and MP3 and AAC
have more aggressive compression and are thus far more efficient than aptX. But
if you have the capability of addressing more bits it’s going to sound better.”
There are two types of aptX you’ll
see on most devices today. There is Qualcomm aptX HD and aptX low-latency.
The HD version supports 24bit/48kHz LPCM audio data which is better than
CD-quality (44kHz/16bit) to better enhance audio quality. As for low latency Bluetooth headphones, this version is best suited when watching movies and
playing games as it reduces delay and ensures the audio is synchronized with
the video. It supports a latency of less than 40ms and 48kHz / 16bit
LPCM audio data.
For example, our new HD601 and
MS301 are equipped with the aptX low-latency technology, which are definitely
perfect for watching videos or playing mobile games.
The Wall