Bluetooth Music Part 2
aptX and aptX HD
Qualcomm’s aptX codec brings wireless audio quality closer to that of CDs. Unlike SBC and AAC, advanced codec is based on compression and stream optimization, final compression is 4 to 1. Bit rate is 352 kbps at 44.1 kHz sample rate and 16 bits.
The upgraded version of aptX HD is superior in quality to audio CD. The sampling frequency reaches 48 kHz with a bit depth of 24 bits and the bit rate is 576 kbps. The compression ratio is preserved: 4 to 1.
Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs
The main disadvantage of aptX and aptX HD is the need to obtain a license from Qualcomm, which is why the number of supported devices is limited. The smartphones include devices based on Qualcomm’s flagship Snapdragon chips. Compatible smartphones and tablets on other platforms are rare, with the latest Huawei and Meizu flagships being the best examples. On the other hand, Apple smartphones and tablets do not support the codec.
Meizu EP52
Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs
The list of aptX compatible headsets and audio systems is much broader. One of the interesting models is the Meizu EP52 headphones with aptX on board. For 2,500 rubles or $ 36.99, the company offers headphones with a flexible head collar. Optimal form factor for sports training and daily use. The back of the case is equipped with Hall sensor magnets. When you don’t need music, just plug in headphones and playback will stop automatically.
Ausdom M05
Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs
There aren’t as many cheap on-ear headphones with aptX support, but the Ausdom M05 model stands out. For a modest $ 43.39 or 2700 rubles, ergonomic carbon-look earbuds are offered. Unlike its competitors, Ausdom is created out of the stereotype of “more bass, cooler sound”. The engineers worked hard to find the right balance. The aptX codec provides high-quality audio over Bluetooth, but if desired, the headphones can be connected via an AUX cable.
Levn receiver
Bluetooth Music: Understanding Wireless Audio Codecs
One of the few devices with aptX HD on board is the Levn receiver / transmitter. The compact accessory adds Bluetooth to any headphone or audio system. A similar device can also be used in an AUX-only equipped car. The audio system connects to the receiver’s 3.5mm jack, which, in turn, connects to the smartphone via Bluetooth. The second function is to stream sound from a smartphone or tablet directly to two pairs of headphones via Bluetooth. The cost of the accessory is quite large – $ 30.48 or 1950 rubles. The additional distribution of aptX HD is questionable, mainly due to the appearance of an even more sophisticated LDAC codec.
LDAC
Bluetooth Music: Understanding Wireless Audio Codecs
The most innovative Bluetooth codec is LDAC. It is developed by Sony. The transmission bit rate reaches up to 990 kbps at 96000 Hz sampling rate and 24-bit depth, the numbers for audio recorded on DVD. Overall the quality is high resolution, but LDAC is still a lossy algorithm, despite the complex encoding and lack of clumsiness inherent in early SBCs. The compression ratio is on the aptX level.
Bluetooth Music: Understanding Wireless Audio Codecs
With the release of Android 8.0 Oreo, the LDAC codec has become part of the Android Open Source Project and is available to all manufacturers of smartphones and tablets based on the Google operating system. For example, LDAC is already compatible with Google Pixel, OnePlus, Samsung Galaxy, Xiaomi and other smartphones that have been released or upgraded to Android 8.0 Oreo and earlier versions.
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Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs Bluetooth Music – Understanding Wireless Audio Codecs
