Assume Bluetooth piped AAC? Apple makes an ass out of you and me

  • The iPhone. With version 7 of Apple’s once revolutionary smartphone we lose the 3.5mm headphone socket (as expected) but gain a pair of Lightning-terminated EarPods and a Lightning-to-3.5mm adaptor for existing ear/headphones.

    As a direct result of this 3.5mm omission, the iPhone 7 becomes IP67 water- and dust-resistant. If you’re prone to dropping your phone in the ocean/pool/toilet then this is progress.

    For audioheads, a large/r question marks hangs over Apple’s other product announcement: Wireless EarPods aka Airpods (US$159/pair). Smartphone pairing is executed with a single tap. Optical sensors and an accelerometer detect each EarPod’s position and the corresponding audio actions. Handling these actions and keeping left and right channels in sync – a little like Devialet’s Dialog router – is Apple’s new W1 chip, reportedly backwards compatible with existing Bluetooth headphones and streamers.


    Similarly, the Airpods are also compatible with other Bluetooth-equipped smartphones. That’s because communication between the iPhone 7’s W1 chip and the Airpods utilises a more power-efficient version of Bluetooth. The Airpods’ 5-hour run-time is extended by a carry-case that doubles as the Airpods’ charger. Sounds like a winner, right?

    Perhaps not. Audiophiles know only too well where the devil resides. Missing entirely from Apple’s September 7th keynote was mention of the iPhone 7’s support for Qualcomm’s aptX codec.

    Filling that void we must assume that Bluetooth audio is still sent from iPhone 7 to Airpods, or any other Bluetooth headphone, using AAC – Apple’s ‘own’ lossy codec of choice. In theory and reality this diminishes the listening experience when directly compared to an aptX-piped Bluetooth pairing.

    Note: despite Qualcomm’s attempts to promote aptX as “CD-like”, it isn’t CD quality; it’s a lossy transmission codec.


    For those toting a pair of Sennheiser Momentum Wireless headphones, an Astell&Kern XB10 Bluetooth amplifier or a Wyred 4 Sound bLINK, better sound quality will more-than-likely result from pairing with an aptX-equipped smartphone – i.e. not the iPhone 7. Here the aptX-loaded Samsung Galaxy S7 betters its Apple rival.

    Only if/when Apple unleashes a) their own superior-sounding Bluetooth codec or b) offers lossless Bluetooth-like streaming is this likely to change.

    For a lossless listening experience with the iPhone 7, the hard-wired Lightning EarPods (or the Lightning adaptor) will likely net a less washed-out sound when streaming Tidal or ALAC. The iPhone 6’s audio output quality isn’t terrible and it’s doubtful that its successor’s SQ will be any weaker. Consequently, Apple’s cord-cutting has the Airpods outsmart their hard-wired cousins on functionality and functionality alone.

    Progress? What progress?

    Further information: Apple


    UPDATE September 9th: An earlier version of this article stated that the Lightning-to-USB adaptor executed its own D/A conversion. This is (possibly) not the case.

    John H. Darko

    Written by John H. 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


    1. So does the 3.5mm adaptor have a DAC and amplifier contained inside? Or does it tap into the DAC/amp within the phone? Same goes for the lightning EarPods, I suppose.

    2. What I’m failing to understand is the main reasoning behind Apple ditching the 3.5mm socket is so they could make it water/dust proof, however there are so may other devices out there with a 3.5mm socket and are still water/dust proof.

    3. Great post John!!!
      Clearly Apple does not care about outstanding playback quality as the focus is primarily on convenience and convenience only. It’s not a bad thing as most use iPhone to listen to music on the go and quite frankly in a 90dB+ travel environment who gives a shit – the music is a background to the journey. However how preposterous for Apple to assume that all folks will be happy with the umbilical cord adaptor or the supplied white buds. Also what is surprising is the price tag for the new wireless headphones – AirPods. Clearly a spinoff of the very non audiophile white buds we will have these poking our butts on every airplane as folks will be leaving these unintentionally behind. Since I have not dropped my iPhone in the toilet once I will surely miss the standard 3.5mm plug as the sound was fairly exceptional for the travel needs and even an occasional plug in into a proper hifi. Convenience kills sound, convenience kills music. Time to dust off the toblerone stick until we have a proper headphones with the direct lighting connector. Hello Audioquest!

      • We already have ‘proper’ headphones with direct Lightning connection, Jerry: Audeze SINE and EL-8 both come with optional Lightning cables.

        • If my experience is anything to go by, the SINE isn’t a proper headphone in the least. Use the Cypher cable and plug it into your iDevice and you get a reasonably balanced sound, but then you swap to the analog cable and plug it into a Mojo (superior compared to the Cypher whichever way you look at it) and you’ll get “midrange city”, with anemic bass and grainy treble. It’s clearly the DSP in the Cypher cable compensating for a mediocre transducer, almost as if the SINE was made as a posterchild for Lightning audio, in order to misinform Joe/Jane Public.

        • Thanks John but these are definitely too big to travel with. I am also bit skeptical about the actual longevity of this type of connector as it is far less secure.

      • Hi, Jerry. Apple is a business and cares about what is relevant to it’s broad customer base; I think we can take it as read that it has done it’s homework and worked all that out.
        Until that ‘broad customer base’ demands higher sound quality, it will continue to provide an auditory experience that will satisfy the majority of it’s consumers. And, actually, that experience is not too shabby last time I checked.
        Meanwhile all the whining and sniping is little more than p*ssing in the wind; Lightning connector, any one? And, yes, we do have alternatives, don’t we?

        • Hi Graham, big companies massage masses into what they think is “good” for them. Remember bass heavy and muddy midrange headphones bought by Apple? While iPhone is a great device with travel sufficient sound fidelity – white bud headphones are not. Removing the worldwide standard forces other manufacturers to expensive retooling. Enjoy the white buds!

    4. Essentially agree, but just don’t say that AAC is “Apple’s ‘own’ lossy codec”. The “A” stands for Advanced, not for “Apple”. AAC is widely used for plenty of reasons. (see AAC is also an evolving family of standard codecs and profiles, including high quality levels (for a lossy codec). Apple cannot change Bluetooth on its own, but it can push for the Bluetooth SIG to work faster, making sure the new BT5 spec solves current hurdles. And it will. When it does, devices based on those standards will benefit. Licensing aptX from Qualcomm? They would have done already if they felt there was a reason to do it.

      • Hence “own” being applied in invert commas – they were the first to take AAC and really run with it in to the mass market.

    5. Any idea about how external DAC/amps will go with 7? Products like Herus, Geek Out, Dragonfly and other USB connected products? And is CCK still the only connector to these?

    6. I’m not sure there’s a dac chip and amp in the dongle or even the Lightning ear pods. Would have to be really really small?

      There still must be a dac in the phone for the speakers, maybe via some software magic they can route the analog audio out through the Lightning port? I have no idea if it’s possible though

      The removal of the 3.5mm jack is as normal with Apple, they can see a future where it’s not needed, saves space, so get rid of it as soon as viable and make everyone catch up.

      • From Wikipedia: “Lightning is an 8-pin connector which carries a digital signal.” Digital. And yet the adaptor’s other end terminates with analgue 3.5mm, therefore it MUST contain a DAC. And yes, it’s really small, just like those that sit inside older iPhone models.

        Yes, one would correctly assume the existence of a DAC inside the iPhone 7 to run the speakers.

        • There is a lot on this that makes a bunch of assumptions. We will have to wait until some can actually tear apart and inspect the W1 chip to actually make a real determination.

          The W1 chip is a System On Chip that clearly has at least the following: bluetooth receiver, AAC Decoder, DAC, and AMP. It also must have some form of communication for synchronizing the left and right ear buds. We have no idea on the quality of each of those components at this points. From the reviews I’ve read they sound better than the default EarPods they are derived from (which isn’t saying much for $29 ear buds). The W1 chip could also include a DSP similar to the DSP included in the Audeze Cypher cable, which could be how they have been able to improve the sound over the previous EarPods.

          I also have never seen anything conclusive that aptX over bluetooth is actually superior than AAC over bluetooth other than aptX’s marketing material. At the end of the day they are both lossy codecs. I’m not saying it is not superior it may be, but I don’t think that is something that we can assume.

          • I’m not *assuming* aptX is superior to AAC, I’ve heard as much. With several devices. As detailed in the article.

            Moreover, the AirPods’ specs clearly state Bluetooth as the transmission medium – see last pic above. As aptX isn’t specified, the connection will either fall back to one of the other codecs supported by A2DP which…

            “… includes mandatory support for the low-complexity SBC codec…and supports optionally MPEG-1 Part 3/MPEG-2 Part 3 (MP2 and MP3), MPEG-2 Part 7/MPEG-4 Part 3 (AAC and HE-AAC), and ATRAC, and is extensible to support manufacturer-defined codecs, such as aptX.[3]”

            • Even if aptX is superior to AAC encoding. Which I will take your word for for now. It still makes zero sense for Apple to adopt aptX encoding.

              Easily 95%+ of music played on an iPhone is 256 kbit/s AAC encoded from the iTunes store. If they adopt aptX all those songs will be first encoded to AAC (loss of fidelity) then re-encoded to aptX (a second loss of fidelity). So by adopting aptX they would have a lower fidelity for the overwhelming majority of music played from the device.

              With AAC they can encode once on the iTunes servers, the data is copied byte-for-byte to the AirPods and decoded there. If they want higher fidelity they can increase the bitrate, or release a software update to support the Apple Lossless Codec as a manufacturer defined codec. Either way supporting aptX doesn’t make any sense for them.

              It would also take more battery to decode then re-encode on the device. End to end AAC makes a whole lot of sense.

              Maybe someone should release an aptX music store to get the optimal end to end music fidelity for bluetooth headphones. If your going to be listening to over bluetooth anyways what is the point wasting the space on your device by storing HiRes lossless tracks on your device and then encoding prior to transmission.

            • For me, this isn’t even about hi-res; if I stream Spotify, which uses OGG, from my Windows Lumia 550 via aptX to the Sennheiser Momentum Wireless, it sounds better than if I stream Spotify from my iPhone 6S Plus to those same headphones. It would seem the streaming service codec isn’t as critical as you suggest.

              Then there’s a related question: if it makes ‘no sense’ for Apple to adopt aptX, why do they include support for it on their Macbooks and iMacs?

            • @John – maybe because of the fact that Sennheiser Momentum Wireless does not support ACC codec. So it just fall backs to SBC

    7. to try to answer the closing question, the direction of progress is clear, and not only to Apple: like it or not, we are heading into a wireless world. For that brave new world not to be too ugly, someone has to improve on existing technologies. Apple, some of their rhetoric notwithstanding, is an evolutionary company; they do things step-by-step, usually starting with what they believe to be the essentials. For a mass-market co that would put ergonomics and functionality first. So, no alarms and no surprises. If more niche-manufacturers, like Devialet, B&O or Naim, push audio-related aspects of wireless transmission further, someday they may end up on smartphones as well. For now, the catchword is just ‘wireless’

    8. “If you’re prone to dropping your phone in the ocean/pool/toilet then this is progress.”

      “The Airpods’ 5-hour run-time is extended by a carry-case that doubles as the Airpods’ charger. Sounds like a winner, right?”

      John, you’re shooting the pearls like machinegun-man!

    9. Removing the headphone jack is a step in the right direction.
      As we have seen with Audeze and the sine cable. Big things to come, technology has to move on, so keep up.

    10. I would imagine that there will be audiophile lightning adapters with their own dacs soon enough. The end result would be superior sound quality with wired headphones for those of us who care.

      • The Dragonflies from Audioquest are almost exactly that; they’re so small, they are a true ‘in-line’ solution.

        • agree…love my dragonfly red to ipod touch 6….when i finally get the chord mojo extender in a few weeks i will swap them out…but while i will probably enjoy the better sound of the mojo, i will miss the small footprint, lightweight form factor of my beloved dragonfly….give technology 2-4 yrs…no doubt we will have a mojo (plus) sound in the size of a dragonfly …or look at the new lg v20 phone…has 32 bit dac….good times we are in

    11. I’ve actually got a great (imho) idea for an iPhone DAC/Amp case, but it’s kind of hard to describe.

      Imagine a case with an DAC stuck to it’s back, something around the size of a Dragonfly. Now imagine someone making a case and Dragonfly-like unit separately, but with the case having slits to slide the DAC into it’s back. The connection from Lightning port to DAC will be done internally within the case, connection routed from the bottom round the back to a “connector” that pipes the signal to the DAC you slide in. Switching to a newer iPhone with different form factor, of have a Nexus or Galaxy? Keep the DAC and get the case made for your specific model, and slide the DAC back in again. All the case will do is act as a conduit for your Lightning/USB signal to the DAC. No external battery.

      Brilliant idea right? …. Oh crap, I’ve just run out of gin….

        • Except that one has it’s own battery and isn’t modular like mine. It’s useless the day you decide to switch phones. With mine, the case and DAC unit are separate units. You just replace the case part for when you get a new phone, detach the DAC from the old case and attach it to the new one.

    12. Sometimes you gotta take a step back to move forward. Cut cord first to satisfy the many; improve dac second (or fourth or fifth) to satisfy the (very) few. Even if the iphone had an excellent dac, many who even care would still prefer to use a dac of their own choosing. And after all, how many features does one expect a company to pack into this tiny device? I actually wish my iphone didn’t even have a camera. Think of how much money one could save not having to have a dual lens in the 7 plus. Those are my individual interests but I understand my needs (or wants) take a backseat to those of the masses. As far as wireless mobile music listening is concerned, how good are most wireless speakers compared to most wired ones? Do we all of a sudden expect wireless phone listening to be amazing!?

    13. The ultimate reason for the move is that Apple’s lightning connector provides a direct digital audio feed. A device that connects to the lightning connecter must contain its own independent DAC and, in the case of an adapter to connect your traditional headphones, a headphone amplifier chip.

      Many audiophiles choose to opt for an external headphone amplifier to drive higher quality headphones. Such devices are typically battery powered and take their audio output from the comparatively low quality 3.5MM output of the iPhone. Apple’s decision to remove that output paves the way for devices which interface directly with the digital lightning connector, resulting in superior sound quality for the end user.

      Such devices can also be powered directly from the iPhone itself which, with the advantage of modern digital amplification could result in some tiny and efficient devices able to easily outperform the bulky portable amplifiers on the market today.

    14. Could somebody generate a competitor for audiophiles – may Samsung Note with that amazing internal dac chip is not it. Love my IPOD.

      • Sony has a few smartphones that have inherent Hi-res support and expandable storage…. And they’ve already got a couple few with some level of water resistance. Not sure about meeting Milspec or Ingress Protection standards though. But they got headphone JACKS! Not sure if their UI is up to snuff, but it’s Sony so… probably.

    15. I have just bought a £400 Bluetooth soundbar with aptX connectivity…..does this mean if i buy the iPhone 7, i won’t be able to connect to it?

    16. For the moment I know only 2 so called “audiophile smartphones” – Meizu 5 Pro and Highscreen Boost 3. Despite on sweet price of last one I never will buy it.

    17. How about having wireless receivers plugged into your ears? How much different is that from holding two smartphones on either side of the head for some nice microwave cooking of your brain? Does that sound like a terribly good idea from a health and radiation perspective? For hours on end? Not to me. And there people are wondering why Altzheimers and related diseases are on the rise…

      • Hi, Srajan. There is a broad consensus that Altzheimers and related diseases are on the increase because we are all living longer…longer…longer…*pfut*

      • I’m also concerned about this. I have a metal retainer and I feel it tingle slightly when I am near Bluetooth/4G or a cell tower. I typically switch off wireless or keep a reasonable distance.

        It’s worth pointing out that earphones alone generate EMF through the magnetic fields even if they aren’t wireless.

    18. Will I still be able to use my dragonfly black with the Lightning to USB adaptor with the iPhone 7?

    19. Srajan Ebaen –
      “How about having wireless receivers plugged into your ears? How much different is that from holding two smartphones on either side of the head for some nice microwave cooking of your brain? Does that sound like a terribly good idea from a health and radiation perspective? For hours on end? Not to me. And there people are wondering why Altzheimers and related diseases are on the rise…”

      Very different. Phones TRANSMIT as well as receive. And that transmission is quite powerful.

      Wireless headphones are just RECEIVERS. And your entire body, head included, is constantly bathed in radio waves, even before you are born. From cellphone towers, radio, TV, radar, etc. etc. And the range of your phone Bluetooth transmitter is only a few yards at most, so its signal is weak, whereas your switched on phone’s main ‘cell’ antenna transmits for miles whether you are making a call or not, as to the things above..

      It’s like the weather – always there. You cant change it so don’t worry about it 🙂

      • This is not exactly true. Bluetooth is not “broadcast” signal, it is a two way communication. True, handsfree/headphones will transmit much less than the audio source, but it still transmits something.

        That said, worrying about microwave radiation with bluetooth/wifi/gsm is silly and no (credible) studies exist confirming any adverse effects from exposure.
        You’re more likely to get cancer from the rubber resting on your head than from the radiowaves 🙂

    20. Apple using AAC does not “diminish” anything. It’s headphone manufacturers supporting only aptX and not AAC who diminish the listening experience.

      See, phone (iPhone at least) will normally store it’s music in AAC format, so transcoding it to aptX will not do any good, transmitting it to headphone as it is (in AAC), will.

      If you want to use wireless studio headphones, or high end wireless listening at home, aptX might be the right solution, but what does it have to do with phone?
      On the other hand, related to phones, aptX is an over-hyped unnecessary rubbish. “CD quality” from AAC source on the go? Let me laugh.

    21. I know for a fact that my iPhone 6S supports aptX (because my headphones produce artifacts in a test with aptX and not with SBC).
      Also, most (all) of the music you play from your iPhone is already AAC. In theory it can be streamed without recompressing, thus producing higher quality sound than aptX even can.
      If you carry only FLAC/ALAC then you’re likely not using bluetooth headphones anyway…

        • I don’t. But I can experimentaly confirm it with my Momentum Wireless + Mac + iPhone 6S.
          I use to test the Frequency Response.
          When using SBC codec, there’s no distortion over the whole frequency range on my Mac. Using aptX there is clearly audible distortion (15K, 12K, most prominent at 10K).
          When I repeat the same test using my iPhone, the distortion is there as well and this to me confirms that iPhone uses aptX.
          It seems to be a bug in the software stack, not in hardware, because there’s no distortion on Windows when using aptX.
          iPhone and macOS have a lot of common, bluetoothaudiod will likely be almost the same code-wise.

          Maybe someone with different headphones can confirm this? But it also may be limited to Momentum Wireless (i.e. caused by some artefacting in combination with ANC).

          Btw there’s a list of supported products on, but they don’t list Macs either – and Macs clearly have aptX support. It’s just a matter of software stack.

          • Macs definitely have aptX support – an option-click on the Bluetooth logo in the system bar can confirm as much. With iOS devices, aptX support not to be included. I went deep into Google and turned up nothing and even a Bluetooth “expert” I spoke to in the USA last month said iOS devices don’t do aptX. So I’m left in the middle, not knowing which is the truth.

            • I stand corrected! Look like my experiment is flawed somehow.
              I looked into log on my iPhone when streaming to the headphones:

              Bitpool: 53, bitrate: 325 kb/s, SBC frame len: 118 bytes, num frames: 7, latency 81269

              But I can still reproduce the artefacting (with aptX on Mac, not with SBC) – no idea what’s going on then…

              But with Bitpool: 53 my ears can’t distinguish between wired/aptx/SBC, so I’m happy nonetheless 🙂

              Sorry for the confusion!

    KIH #35 – Tensegrity

    Bring the bass back with DEQX and Dynaudio