WHEN ‘GOOD ENOUGH’ ISN’T GOOD ENOUGH
Among all the wonders of streaming smart amplifiers and LED projectors and OLED TVs this issue, there was one small but intriguing demonstration of the subtle but insidious effect that low bit-rate signal transmission can have on music.
Many of us have come to live with Bluetooth in one situation or another. All four of the smart amplifiers here include it so you can easily throw tunes wirelessly from your phone or tablet straight into your hi-fi. Little Bluetooth speakers are ubiquitous, and of course Bluetooth headphones are taking over the market last year was the first time their value exceeded that of wired headphones in some places; the trend is clear.
We know that Bluetooth is not CD quality. It never has been, and even now that Bluetooth 5 is rolling out with extended specs and improved speeds, there’s no guarantee those new abilities will be easily applied to higher audio quality (see avhub.com.au/blue5) audio seems a blind (or deaf) spot for the group responsible for Bluetooth, which concentrates on ways to improve efficiency and decrease power consumption for phones and computers, and more recently the nebulous Internet of Things.
It seems likely that any push to CD quality and beyond will be left to proprietary formats rather than standards. So as with aptX currently, you’ll need both your phone/tablet and your receiving device to support that particular technology. That’ll be slow to implement and too brand-specific for my liking. Does it matter? Isn’t Bluetooth ‘good enough’? Sometimes, yes. We’ve heard some great Bluetooth speakers and headphones where manufacturers have carefully tuned to the weaknesses of Bluetooth to give a good result. And it’s always interested to compare wired versus Bluetooth sound on headphones that offer both. Often the wired sound seems deliberately bright, perhaps so that things don’t get too softened when using the lower quality Bluetooth connection.
But I don’t recall anything quite as clear as the change in the Pioneer headphones this issue (p80). These are gorgeous-sounding over-ear designs which I used and loved as wired headphones for a couple of weeks without knowing their price or model number, and only realising they were also Bluetooth headphones when I spotted the power button on the headshell. Switching to Bluetooth, there wasn’t a vast change in frequency response, yet the sound quite drastically lost its magic. Where I had previously been drawn deeply into music and mixes and orchestras when using a cable, now things were nice enough, but just ‘nice enough’. Perfectly enjoyable for the daily commute, but back in a quiet environment they no longer transported us into the wonders of music as they did with a cable (when we had judged them to perform way way above their price).
There are several possible reasons the lower bit-rate, possible losses and inaccuracies incurred by the likely concatenation of codecs involved in Bluetooth transmission, the difference in DAC, amplification and audio circuits driving the headphones. The result was subtle information loss, the edges that deliver shape and presence, that old devil in the detail, which effected almost a dimensional difference, demonstrating the losses Bluetooth can incur. (I should mention that most of the comparison was made using what would have been the middle rung of available codecs, AAC rather than aptX, but certainly not the rock-bottom default SBC.)
The thing is, most people won’t know what they’re missing. We’ve just accepted Bluetooth for its ubiquity and ease of use when we could easily have something better, now that the technology has caught up. Bluetooth 5 is capable of CD-quality and more, but there’s no sign of a standard being offered for it. So for headphones, as with home networking, I’m inclined towards the confirmed maxim that for audio fans, if you can cable it, then do cable it.
A footnote before I go, to mention an alarming recent lyric from talented songstress Katy Perry. “Turn it up it’s your favourite song,” she sings in the lead single from her new album ‘Wasted’. Then “Dance dance dance to the distortion / Come on turn it up keep it on repeat / Stumble around like a wasted zombie / Chained to the rhythm.”
Now I have no objection to being chained to a rhythm, or indeed slaved, as any fellow owner of the Grace Jones 12-incher with its famous bass descent will attest (heard one summer’s day at Max Townshend’s apartment by the Thames through one of his floor-to-ceiling masterpieces of loudspeaker dom, this note descended yea, deep enough to warm one’s insides to the very cockles, thankfully stopping just short of the dreaded brown note). Nor do I have any particular objection to millennials being invited to stumble around like a wasted zombie, as they seem well enough practised in this already. No, it is her encouragement of dancing to distortion at which we audio lovers must all protest. I don’t want to incite a hate campaign or anything like that, but I would certainly encourage all self-respecting audiophiles to tweet something respectful and polite to Ms Perry (@katyperry) including the hashtag #pleasewarnyourfansthatdancingtodistortionmaybebadfortheirearsthankyouforlisteningandwelovedyouatthemanchestergig.
OK. With that off my chest, I hope to see many of you soon at the Australian Hi-Fi & AV Show in Sydney; we’ll have a NextMedia stand somewhere around the main reception area. Cheers!