What is AptX?
As more and more device manufacturers have the courage (read: stupidity) to remove the traditional headphone jack from their phones, more and more consumers are going to be drawn towards using wireless headphones. I’ve been using different pairs or wireless earbuds and headphones for over three years, and although I do like the convenience, there are definite downsides. My first pair of wireless earbuds was a pair of Jaybird Bluebuds X, and within a year of owning them the (already not great) 8 hour playing time was reduced to less than two hours. Jaybird was kind enough to replace them with another set, but that’s something I wouldn’t have ever worried about with a set of wired earbuds.
Another big issue is sound quality. Bluetooth still cannot transfer data as quickly as a wire can, so sound quality takes a hit over a wired connection. In practical terms, this means you wouldn’t be able to hear a background instrument or vocal track that could be discerned if you were using a pair of wired headphones. AptX is a technology now owned by Qualcomm to solve this.
AptX requires both the device playing music (your phone, computer or other audio device) and the receiving device (your headphones or car stereo) to have the AptX functionality to work. In simple terms, the audio is compressed on the host device, sent over the Bluetooth stream, then decompressed by the receiving device. Because the compressing and decompressing allows more total data to go over the Bluetooth stream, the songs will have more detail like the background instruments.
Whether you’ll be able to tell is another thing. When I was doing my headphone trials last year, I sat down with the Bose QC-35, Sennheiser Momentum Wireless and Sony MDR-100ABN headphones. The QC-35’s do not have AptX, while the other two do. I was using a friend’s HTC 10 for the test, and that phone is pretty well regarded within the audiophile community. I don’t have the greatest hearing — some run ins with some helicopters did that — but I was still able to tell a bit of a difference between songs played to the QC-35 and the same songs played to their other two headphones. I had to sit and focus on nothing else besides listening to the music to tell a difference though. In my day to day life — listening to music while I type out homework or an article — I wouldn’t focus enough on the music to tell a difference. In the end, I stuck with the QC-35’s since they were more comfortable anyway.
Standard AptX promises CD-like quality over the wireless connection, which is much better than the standard Bluetooth protocols. There are two newer variants of AptX that focus on solving different problems. The first was AptX Low Latency, aimed at synchronizing wireless audio better for video watching and game playing. AptX Low Latency promises less than a 40 millisecond delay time so the mouth movements of characters on screen don’t look out of sync with what you hear. There are quite a few headphones with AptX Low Latency, but I wasn’t able to find many products with the technology built in. Fortunately there are USB adapters to upgrade systems.
The newest AptX version is AptX HD. AptX HD supports audio up to 96 kHz sampling rates and resolutions up to 24 bits. While standard AptX promises CD quality, AptX HD promises lossless quality: the sounds quality you hear should be the same as the original studio masters. It will also be virtually indistinguishable from listening to music over a wire. In addition to having a host and receiver that both feature AptX HD, you’ll need to have high quality music files as well. There are a few sites such as HDTracks that sell lossless files, they don’t have anywhere near the catalog that iTunes or Google Play have. TIDAL is an option for streaming music fans, and while they do have an extensive catalog, most of the catalog is the same quality as other streaming services. Another option is to buy a vinyl record and rip the files to your computer, but that’s very time consuming. As of right now, it’s better to wait anyway: the only AptX HD headphones are two new (and expensive) pairs from Audio Technica, and the only phones that feature AptX HD are the LG G5 and V20. If you’re an Apple or Google fan, you’re out of luck: neither the iPhone nor the Pixel feature AptX.
AptX doesn’t solve all of the problems with wireless headphones: they are still susceptible to signal degradation and interference, they are still one more battery to charge and the batteries will eventually degrade. However, they greatly improve the sound quality. If you’re curious what products support AptX, there is a handy list on the AptX site.
