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Global feedback: the battle for gapless playback, vol. 2

  • Fabric. Earlier this month, the iconic London club was forced to close by Islington Council in the wake of two drug-related deaths. Maintaining the club’s legacy is an close-to-peerless series of compilations that offer the finest dance/electronic music of the moment, mixed by some of the world’s best DJs.

    At time of writing, we’re up to volume 89 in each of the Fabric and FabricLive series. That’s 178 DJ mix albums since 2001, all from a single label. Further afield, there exists hundreds of other record labels doing much the same.

    For fans of electronic music, especially throughout the 90s and 00s, the mix CD was a way to get a taste of the DJ’s selections and mixing skills without attending an event. Others use the DJ mix as a way to carry the weekend’s party vibes into the working week.

    Skilfully mixed, the best mix CDs deliver more than the sum of their parts: Jimmy Van M’s Bedrock mix, James Holden’s At The Controls, 2ManyDJs’ As Heard On Radio Soulwax Vol. 2, Sasha & Digweed’s Northern Exposure Vol 1. (and 2!), Joris Voorn’s Balance and Function’s Sandwell District Fabric mix all rate highly.

    sandwell

    Irrespective of any intrinsic artistic value, the DJ mix is rendered unlistenable without the presence of gapless playback. Even the tiniest audible gap between tracks disturbs what is meant to be continuous mix; its flow is compromised.

    In the CD era, this wasn’t an issue. CDs are pressed as one track with the track segmentation applied virtually by the disc’s table of contents, as read by the CD player. But as owners have ripped those CDs to hard drives or purchased as a download, tracks arrive as separate entities.

    For proper gapless playback of digital files, the music playback software must read ahead and buffer the incoming track before the currently playing track comes to a close. This often requires two CPU threads: one to handle playback now and the other to pre-fetch file data that will soon require playback. (My technical understanding of the nuts and bolts of gapless playback extends no further than this).

    Nowadays, it’s not only locally stored files that require gapless handling. Streaming services are now very much part of the audiophile lexicon, especially Qobuz’s, Tidal’s and Deezer’s lossless tiers.

    Users might grumble that the Sonos ecosystem doesn’t yet support Spotify Connect (that changes soon) but the Santa Barbara-based company have ensured that gapless playback is present and correct for Tidal and Spotify (and other services) as well as all LAN-streamed content.

    Tidal’s desktop and smart device apps each play gaplessly but the Tidal playback engines coded into the Google Chromecast Audio, OPPO BDP-105 and Devialet Phantom/Dialog do not. It’s why I chose to connect an AURALiC Aries Mini to the Dialog’s single TOSLINK port – Lightning DS puts gaplessness back on the map, all of which might not be apparent to the casual observer who must get hands on him/herself to find out the hard way* [see footnote 1].

    It’s been three years since I last tackled this issue – catch up here. My beef back then wasn’t necessarily gapless playback’s absence but that many a hardware manufacturer shied away from declaring it. And if they did, we were encouraged not to sweat it – a firmware fix was apparently ‘just around the corner’.

    How long that wait was unknown – a reminder to never buy on the back of a promise. As many a PS Audio Bridge owner will recall. In 2011, Paul McGowan spent a good deal of time and money trying to erase the gaps heard from the first generation Bridge. He eventually threw in the towel and built more powerful hardware; the Bridge II offers no such intra-song limitations.

    dettmann

    Like many hardware companies, not all software houses see gapless playback as a nice to have extra. “It’s critical”, said Roon CEO Enno Vandermeer upon learning that his playback engine was splicing tiny gaps between each track on Marcel Dettmann’s Fabric mix when played on my Macbook Air. The ensuing Roon update fixed the issue pronto.

    The absence of gapless playback can really strip the shine from a new DAP or network streamer purchase. I now ask about a device’s gapless abilities BEFORE picking up a review assignment, just as a consumer might before dropping big coin.

    At CanJam SoCal in March, a pre-production HiFiMAN SuperMini caught me off guard. Its lack of audible treble glare (that I hear from the Sony NW-ZX2) primed me for a review when the time came. Before requesting a sample unit in the wake of HiFiMAN’s recent shipping announcement, I hit up the Chinese manufacturer via its Facebook page: “Does it [the SuperMini] do gapless?”. “YES!” came the resolute reply. Good-oh. Hit me.

    hifiman

    With the review unit’s arrival came trouble. My first impressions about its more organic sound were confirmed but the firmware saw the SuperMini ask if I wanted to format the microSD card (it reads FAT32 only) each and every time I inserted it anew. “It’s a bug with the current firmware. We will fix it with the next firmware update,” said HiFiMAN’s Riccardo Yeh.

    What couldn’t and wouldn’t be fixed apparently was the unit’s absence of gapless playback.

    “How do I enable gapless playback? Right now each song fades out quickly at the end before the next one fades in quickly when it starts – no good for DJ mixes,” I asked.

    On a related note, the SuperMini’s track start ramp-up robs any track announcing itself with a thwack of its initial attack. Think: Bob Dylan’s “Like A Rolling Stone”.

    Yeh’s reply retrospectively announced an 11th hour change: “They close the gapless function to make sure the CPU can work under single threaded mode and avoid the jitter as much as possible. Dr. Fang insists that this is a “must” sacrifice for superior sound quality.”

    “It’s a pity that we won’t develop the firmware featuring gapless playback for SuperMini in the future,” added Yeh 24 hours later.

    supermini_2

    A necessary sacrifice according to HiFimainMAN Dr Fang Bian but not one this listener is prepared to make. DJ mix CDs, live albums or any album where seamless track transitions are “as the artist intended” are pushed into the background. Review cancelled, unit returned to sender.

    Dr Fang’s functional sacrifice will also affect the freshly announced, crowdfunded MegaMini.

    It isn’t just HiFiMAN. The Chinese xDuoo X3 suffers the same gap-toothed look. Thankfully, this Rockbox port removes the holes.

    CDs are gapless. Ditto vinyl records. In moving forwards with digital audio, we are sometimes being asked to accept the backwards step of its implementation. Reasonable? For this techno fan, a lack of gapless playback signifies a refusal to acknowledge the artistic intentions that sit behind an enormously popular sub-genre of music.

    However, it is important to ask: is gapless playback a minority concern? Over to you then, dear reader, for the bigger picture. Have your say in the comments below after voting in the poll:

    [poll id=”7″]

    Please let us know of any other devices that don’t offer gapless playback.

    Footnote 1: Not my intention to single out Tidal here but it’s the lossless streaming service that I (and others) use most often.

    John Darko

    Written by John Darko

    John currently lives in Berlin where creates videos and podcasts and pens written pieces for Darko.Audio. He has also contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

    Follow John on YouTube or Instagram

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