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Review of Apple and Amazon Music service audio quality.

Posted: Fri Feb 24, 2017 12:51 am
by embleton
Apple Music streams its own service through its use of Advanced Audio Coding (AAC), its a relatively good sound at a fixed bit rate of 256Kbps. Whereas Amazon Music streaming service is through the open audio compression MP3 format at an average 256Kbps variable bit rate (VBR), which when the streaming was done through a DacMagic Plus via a Bluetooth Cambridge BT-100 receiver the music fidelity seems better by miles.

I was unsure why the music fidelity seems more bouncy, dynamic and responsive from the Echo Dot, as both were played through the DacMagic Plus. Further tests were done to ascertain the reason for this disparity; but my assumption is that the Apple TV 4th generation 44.1 KHz to 44 KHz oversampling maybe the culprit through my TV. As I’ve an iPhone 7 Plus and iPad Pro further investigation was warranted using AirPlay and Bluetooth through the Cambridge BT-100 Bluetooth receiver.

After several tests my engineer ears ascertained quantization noise was causing some of the issues through the stages from my Apple TV DAC PCM decoder and then resampling done by the Samsung JU6445 UHD TV PCM to its optical stage or Bluetooth output.

A simple reconfiguration of the Samsung JU6445 UHD TV solved the majority of the issues, by stepping through the settings and changing the HDMI audio input to bitstream on the Samsung, something I’d not considered until purchasing the Amazon Echo Dot and Cambridge BT-100 Bluetooth receiver for the DacMagic Plus, was done.

It was going to be a long night to choose a winner in the audio quality between the two with my engineer ears, but the American artist Melody Gardot would steer the direction to its eventually winner by my ears.

It was Amazon’s choose of MP3 encoding for the source, for this young singers yonger years vocals from the song Baby I'm a Fool were clearly heard with the Amazon’s music collection MP3 encoding rather then Apple’s music AAC encoding. A lesson Apple should learn, is to ensure before implementing its own format on us, is, it shouldn’t be inferior to one in production and in use.

Primary audio test environment; Apple TV 4th generation (Apple Music) or Amazon Echo Dot (Amazon Music) through Bluetooth to Cambridge DacMagic Plus via a Cambridge BT-100 Bluetooth receiver, to an Onkyo A-9010 stereo amplifier that is bi-wired to a pair of Tannoy special edition speakers.

Winner in audio test Amazon Music from Amazon Echo Dot, which is a real surprise!