Jon Bentley compares the sound quality of aptX against Bluetooth
26 Apr 2016
I’ve long regarded wireless headphones as inferior to the wired variety when it comes to sound quality, something I’ve attributed to the extra compression required when streaming music over the Bluetooth connection they normally use. As a result, in spite of getting rather cross when, for example, my cable gets tangled up on a door handle when I’m listening to my music player round the house, my current headphone collection is completely wired.
But there’s a new form of Bluetooth compression that claims to offer the sound quality of wired headphones with the cable-free convenience of wireless. It’s called aptX. And in this week’s show I attempted to answer the question “Should we all buy aptX headphones?” Helping me were esteemed drum and bass duo Sigma, otherwise known as Joe Lenzie and Cameron Edwards, who agreed to test conventional Bluetooth, aptX, and wired headphones head to head.
For the first part of the test I met them on a party bus where it soon became apparent that the biggest problem with Bluetooth headphones for them wasn’t sound quality, but the significant processing delay they introduce when DJ-ing. This ‘lag’ between cueing a sound and hearing it was marginally better with aptX, but both would be useless in a profession where precise timing is so crucial. Certainly the wired headphones used in this part of the test were easily the most responsive and, tellingly, the Sigma boys have no plans to change their trusty wired Sennheiser HD25s any time soon.
To concentrate on sound quality we moved to a nearby recording studio. There we listened to the same track - Sigma’s engrossing Stay - on the same type of high quality headphones - Bowers and Wilkins P5s - using them wired, wireless over conventional Bluetooth, and wireless via aptX. All tests were blind and in a random order.
One thing was immediately obvious. They didn’t sound hugely different. Joe marginally preferred the aptX and the wired headphones, and felt the standard Bluetooth was poorer, which supported aptX’s claims. But Cameron actually rated the standard Bluetooth as slightly better than the wired or aptX.
The results of our sound quality testing were therefore somewhat inconclusive. One couldn’t say categorically that aptX, wired, or even standard Bluetooth sounded best. My question as to whether to buy aptX headphones therefore remained unanswered.
But there was one bit of good news from the day. Whether aptX or not, Bluetooth in itself doesn’t appear to degrade sound quality as much as you might expect. So, while wireless headphones may often be poor I now strongly suspect this isn’t down to Bluetooth itself.
Maybe the shortcomings I’ve experienced with wireless headphones are due to weaknesses in their electronics that have to re-amplify the Bluetooth signal to play it back at an acceptable level. Or perhaps the quality shortfall comes from cramming this circuitry, and the batteries needed to power it, into the earcups, leaving less room for the drivers, the small speakers that produce the actual sound. Whatever, Bluetooth doesn’t necessarily lead to bad sound.
As for aptX versus standard Bluetooth, though, if even professional musicians can’t agree on aptX’s superiority the jury’s still out.