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The inconvenient truth about MQA on iOS

  • The email that read “Stream Tidal Masters everywhere: iPhone now supports MQA” called for immediate care. This wasn’t Apple embracing MQA technology directly but an extension of Tidal’s existing MQA support.

    Two years ago, Tidal made its repository of MQA ‘Masters’ streamable to anyone subscribing to the company’s ‘Hifi’ tier — and at no extra cost. Nice. The announcement covered Tidal’s MacOS and Windows apps.

    Last year, Tidal rolled out MQA support to Android devices and earlier this week, per the aforementioned email, iOS app users were now being invited to the MQA party. They too could now stream Tidal’s MQA Masters directly to their iPhone (or iPad).

    Anyone doubting the need for reducing hi-res audio streaming’s data usage in an age of 4G/5G connections has probably never been forced to rely on a smartphone as their only Internet hookup. Making a monthly data allowance go the distance takes skill and organisation.

    MQA isn’t only posited as a bandwidth-efficient delivery mechanism for hi-res audio streaming. Any folding and unfolding of sample rates above 48kHz are, as asserted by MQA the company, bookended by correction of time-smear wrought by the recording studio’s A/D converter and the end user’s D/A converter.

    However, for many users, MQA’s hi-res audio delivery mechanism is its main drawcard. Tidal’s iOS app will now ‘unfold’ any 24bit/48kHz MQA stream to 24bit/96kHz – and any 24bit/44.1kHz MQA stream to 24bit/88.2kHz – and pass the result on to the downstream DAC. MQA call this the ‘Core Decoder’. Many audio enthusiasts call this ‘the first unfold’.

    Now we ask ourselves: which DAC?

    Using the DAC inside your Bluetooth headphones? Forget about MQA. Forget about CD quality audio too. Bluetooth doesn’t yet support lossless audio transmission.

    There is a DAC inside every iPhone but for the iPhone 7 and beyond it talks only to the in-built speakers. For hard-wired headphones, we look to Apple’s Lightning to 3.5mm audio adapter.

    Here comes the rub. This dongle’s internal DAC resamples all incoming audio to 48kHz before decoding it to analogue. CD-quality audio handling is possible (if not bit-perfectly handled) but any hi-res (MQA) audio unpacked by Tidal app’s is immediately downsampled to 48kHz.

    This doesn’t rule out iPhone users hearing MQA’s pre-emptive A/D time-smear correction. It simply means the Apple dongle doesn’t support hi-res audio. Similarly, this 48kHz ceiling kneecaps hi-res audio streams spilling from Qobuz’s iOS app.

    TL:DR. Apple’s iPhone simply doesn’t do hi-res audio.

    Here, MQA or not, an external DAC is required. Bulky, mains-powered DACs leave the spirit of the iPhone’s portability at the front door. iFi’s Micro and Nano DSD BL support MQA and come pre-loaded with battery power for go-anywhere usage that doubles up on the iPhone’s in-pocket intrusion.

    Going smaller still, the AudioQuest DragonFly Red and Black complete the portable MQA picture with minimal added bulk and without asking us to monitor/recharge a second battery. Connected to an iPhone using Apple’s Lightning to USB dongle, the iOS app Tidal will execute the first unfold to squirt the resulting hi-res digital stream directly into the DragonFly. The AudioQuest dongle DAC will then execute any second unfold and handle MQA rendering (DAC correction). Look for the purple light.

    Two years ago, the inconvenient truth about MQA was that Bob Stuart and Peter Craven’s audio technology sounded better. That we are able to stream studio masters directly to our home hi-fi systems in 2019 is a modern miracle, but the inconvenient truth about MQA on iOS is that Apple’s refusal to embrace hi-res audio means iPhone users can only “Stream Tidal Masters everywhere” with third-party hardware intervention.

    Tidal + MQA + iPhone = 24/96? No, sir.

    Tidal + MQA + iPhone + external DAC = 24/96 (and beyond). Yessir.

    Further information: MQA

    John H. Darko

    Written by John H. Darko

    John is the editor of Darko.Audio, from whose ad revenues he derives an income. He is an occasional contributor to 6moons but has previously written pieces for TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

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