APT X is the newest bluetooth codec that improves wireless sound quality by improving methods of compression made possible by the higher bandwidth of bluetooth 4.0.
The first thing to know about APT X is that both ends of the bt communication must be capable of APT X in order to use the codec. The second thing to note is while the only apparent hardware requirement is a bluetooth 4.0 chip, the codec itself is liscensed by CSR so any manufacture who’d like to use the codec must pay for the license which is why budget devices, even meeting all hardware requirements (ahem Nexus 6P) may lack APT X.
A quick Google search for APT X brings up some comments from other reviews and blogs that really make me sad for the direction that the public’s understanding of audio quality. I can’t be angry becuase every person has their own personal preference for audio quality, but the introduction of APT X to bluetooth is as big an improvement in audio quality as the implementation of the Compact Disk and yet bloggers claim that most won’t be able to notice the difference in audio streamed with APT X enabled. The problem is these people have no idea how compression affects sound quality. The largest data that is affected by compression is Bass, so obviously your going to pay attention to the accuracy, timing, and frequency not just the level of the bass. Every other spectrum is improved as well as well as the whole resolution of the audio.
I tested this out by syncing some moderately priced apt x enables bt headphones to my wife’s nexus 6P (no APT X) and play in various mp3 files as well as spotify in both high and low quality streams. I then compared that response playing the spotify me files and songs on my APT X enabled Galaxy Note 4. The results we as expected, the largest area of improvement being the tightness and accuracy of lower end spectrum. Over all, it’s the same response you get when switching between low bit rate audio and standard mp3 bit rate (128 kbps or higher). The quality was immediately obvious to me despite admittedly often having difficulty hearing certain aspects of audio that audiophiles generally use to describe ideal sound. My point here is that it does make a difference, a huge one! The problem is suppose is that people who care about sound quality don’t use wireless headphones for that purpose. Even with Apt X, there’s no comparison to a solid pair of wired phones. So the consumers and “expert reviewers” for them will just continue to spread misleading and flat out wrong information without doing any A B comparison.
So here ends my rant on Apt X and the one thing to take away from this is: unless you have partial hearing loss, APT X is worth it for bluetooth headphones.
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