It is often said that you can’t have your cake and eat it too. Fellow lovers of high-quality audio prepare to rejoice; our cake has arrived, and we shall be eating it. Long have we been forced to choose between having cabled headphones with all the frustration that goes with them, or no cable and lower quality audio. Now there is an option that lets us listen to superb high-fidelity audio without having to endure the tangle of frustration. This new all-encompassing option is aptX HD Bluetooth audio.
Introduce in 2016 by Qualcomm the aptx HD wireless wonder chip can transmit 24-bit 48Khz audio from your phone to a compatible Bluetooth device. Typically, most wireless devices are trapped in 16-bit audio land, an audio standard from the land that time forgot, otherwise known as the 80’s.
So, you may ask yourself if an extra 8 bits can make a difference? The answer is wholeheartedly YES. After using a set of basic Bluetooth headphones for a year I recently upgraded to a set of Sony CH700N over ear headphones. When combined with a top end phone, Sony Experia XZ Premium in this case, a magic little option is enabled within the Bluetooth settings, a magic little switch labelled aptX HD Enabled. With aptX HD turned on the richness of the audio was instantly noticeable. Clear, incredibly defined and so rich the quality was breathtaking. So great was the difference that I couldn’t help but force all those around me to try out my new high-fidelity headphones. Some phones will label the option differently but generally it will be described as HD audio.
Currently the phones that support aptX HD include LG (everything after the G5), Sony, OnePlus, Huawei and Google. Apple doesn’t support aptX or aptX HD, they instead use AAC (Advanced Audio Codec) to support near HD quality audio over Bluetooth. Only a handful of Samsung phones support aptX, none support aptX HD. If your phone doesn’t support one of the new codecs chances are it is using the original Bluetooth SBC codec (Sub-Band Compression). This simple codec is responsible for many believing Bluetooth can’t satisfy their high-fidelity needs, it really does sound very average after hearing aptX HD. I imagine the difference between SBC Bluetooth and high-quality USB-C cabled headphones with a 24-bit DAC is equally large.
Bluetooth can use many Codecs to compress/decompress audio for transmission, the family of aptX Codecs are one of the many attempts to improve the quality of audio above the standard SBC codec. Qualcomm is continuing to evolve aptX with new codecs that will continue to improve audio quality. aptX Adaptive has recently been introduced and provides the ability to vary the bit rate depending on the quality of the Bluetooth connection, which will elliminate drop outs. Qualcomm are also working on a 24-bit 96-Khz codec extension to aptX.
So far the only downside I have experienced with aptX HD are the drop outs. You need a strong connection between devices in order to support the transmission requirements, any interference can cause the audio to drop out. aptX Adaptive will address this by dropping the data rates to suite the connection. To be honest I haven’t found it to be a huge issue, I generally just move my phone to a spot that gets a better connection, strangely my front left pants pocket seems to work best.
So, if a high-quality listening experience is important to you and you don’t want to have to deal with the tangled frustration of headphone cables then hunt down aptX HD compatible devices. I will definitely be making sure my next phone is on the compatibility list. Till then if you see someone walking down the street grinning and tapping to the beat that is probably me enjoying the 24-bit goodness of aptX HD.