Time to clear some misunderstanding about digital and analog audio

It all started with a rumor that Apple will ditch 3.5mm audio port in next iPhone. Then LeEco and Motorola ditched 3.5mm port on their phones (LeEco Le 2, Le Max 2, Motorola Moto Droid Z, Droid Z Force). The future is digital and there is no denying this fact. The time of traditional headphones with fat plugs and long cables is coming to an end and will be replaced by headphones that can do lot more and by wireless audio. There is some misunderstanding that I have noticed (on Facebook, Twitter etc) and in this post I explain some basic things that will help you understand why the world is moving to Digital Audio. Please do add your input by commenting on this post if you agree or if there is are any errors in the article.

Audio vs Sound

Sound is what our ear recognizes. Sound is a mechanical vibration/disturbance that passes through a medium. Audio is an electrical signal that is generated artificially. A musical instrument like a guitar or a drum makes sound, a recording instrument like microphone records audio by converting the mechanical vibration (sound) into electrical signal (audio). A phone generates electric signal (audio) and passes the signal to earphones/headphones/speakers. This signal is process and is converted into mechanical vibration by speaker’s diaphragm (sound). When it comes to sound, there is only one format (vibrations). When it comes to audio, there are various formats (digital, analogue, high definition blah blah) Now, you should know the difference between audio and sound.

Digital vs Analogue

Analogue audio signal is a continuous electronic signal. The reason why audiophiles have vowed for Analogue is that an analogue audio signal is closer to a natural sound in the sense that it is smooth and continuous and so an analogue signal captures the true form of sound. Digital audio signal is not continuous and is represented by 1s and 0s and audiophiles say that subtle changes are missed in digital form. Modern recording has advanced to an extent that this claim is now baseless. Also, given that most of the modern audio playback devices are ‘digital’, there is no point in saying that analogue output is better. The only way analogue can beat is when the recording, storage, processing and playback devices are all analogue. When you hear music over LPs (a.k.a vinyl records) that play lossless music and compare it to music played through iPod or whatever, the difference is noticeable, if not staggering (unless you use lossy mp3 audio file that removes certain parts of audio).

Digital audio playback has never been about superior audio quality, it has been about ‘ease of use’ and ‘follow the world’.  The world is not interested in carrying analogue audio material (cassettes, vinyl records, tapes etc) neither is the world interested in carrying CDs. What the world needs is audio playback devices that does not consume space (any). This is a simple reason why smartphones are killing every other audio playback device. Even for recording studios and artists, a digital format is much easier to store, process and distribute.

Cell phone audio

Lets take the common approach where users play an mp3 or streaming audio and connect headphones to the smartphone. The audio is now in ‘digital format’. The CPU parses the audio file/stream and sends it over to the Digital-to-Analogue (DAC) converter that processes the stream and sends over the ‘analogue electrical signal’ to the amplifier which well, amplifies the signal. The signal is then passed to the headphone/speaker connected to the 3.5mm port. The headphone then coverts the analogue audio signal to mechanical vibrations (by the diaphragm in the speaker) and the ear picks up these vibrations (succesfully recreating the sound).

The problem with this approach is that the quality of the audio is as good as the quality of the DAC. Do note that digital to analogue processing is not a simple task. If its a single note of speech, its easier but todays audio that contains so much of detail, various instruments and multiple voices makes audio processing a complex task. The LYF Wind 1 phone that I am using has a really bad audio processor and whatever high end speaker/headphones I use, the signal quality will not get better. When I compare the output to the same from my Apple iPhone 6, the difference is mindblowing. Even if I use ultra high end headset with LYF Wind 1 and use apple provided earphones with Apple iPhone 6, the quality of sound will be better for the latter. This does not mean that the headphone that Apple provides is better, it means that the LYF Wind 1 phone is really bad in producing sound.

USB and Lightning audio to the rescue

This is where the newer USB Type-C and Lightning ports come to the rescue. Take the LeEco Le 2 and Le Max 2 phones as an example. Both these phones come without a 3.5mm ‘Analogue’ audio jack and the audio output is by:

1. USB Type-C headphones
2. Type-C to 3.5mm adapter
3. Bluetooth headphones

There is no audio processing done on the phone when you use digital audio output via Type-C. The headphones will contain the DAC chip and the circuitry to do the magic of audio processing, apply noise cancellation and whatever gimmicks are necessary. This way, the quality of sound that your ears get is as good as the headphones that you use. Coming back to LeEco 2nd gen phones, both the phones will provide same audio quality so you do not have to buy an expensive phone if your only requirement is ‘quality audio output’.

Those who used to play with audio setups (home theatre etc) are well known with the term ‘audio passthrough’ where the audio is passed to the external amplifier unaltered and the better the amplifier and speakers are, the better the sound quality will be.

Do remember that USB Type-C allows analogue audio, audio processing is done on the phone only when you use a adapter to connect to traditional headphones/earphones. 

Not just about audio

The lightning port is used to carry data too so you can now have headset that can monitor your heartbeat, count steps etc and send the data back to the phone via the lightning port so that eliminates an extra device to carry. This is just an example of what can be done with the ‘one for all’ port. There can be superior controls that can be added to the headphones, speech processing can be done on the headset itself, you can have advanced noise cancellation, the signal interference from external noise will not be a problem anymore as digital to analogue conversion is done in the headset itself.

More space for phone makers

When we asked Smartron designer why the bezel around the tablet is so wide, he said that it is due to the USB port. The same applies to 3.5mm jack too. it may look like a small round hole but the depth and additional circuitry needed eats precious space inside a smartphone. This means that the makers can either make the phone lot thinner or bigger battery can be used or some other technology can be implemented.

Wireless audio as mainstream

If you are using Bluetooth for audio playback, you already know how much more comfortable it is. The problem with Bluetooth is that the speakers and headphones are still very expensive and still considered ‘premium’. With the advent of digital audio, the demand for Bluetooth audio playback devices increases and this will slowly bring the price down, makding them mainstream.

The problems

There are various issues that are making me uncomfortable. Type-C is a new technology and there were instances where the charging cables killed phones (due to lack of understanding by some cable manufacturers) and the same can happen with the headsets too. Moreover, the new type of headphones will cost a lot (due to the R&D costs involved) and this will definitely anger some consumers. Suddenly, you have to cough of 2000 or more just for basic headphones when the same were bundled for free earlier when phone had 3.5mm jack.

With a single port for everything, you cannot charge your phone while you are playing music on your headphones (well, unless you are using wireless audio or wireless charging). We do hope that split adapters (that create two type-c ports from one) are released soon but then again, with lack of knowledge, these things can do more damage than good.

Conclusion

Old things and technologies are discarded every once in a while and the analogue audio on phones is the only old piece of tech and whether you agree or disagree, the change is going to happen sooner than later. If Apple ditches 3.5mm jack on their next phone, this is going to accelerate. Motorola’s Moto Z is another phone that does not come with an analogue audio port. Be prepared for the change and you will be happy to move.