About audio and USB-C
Is the switch to USB-C good or bad? Why is it happening and what does it mean for those who like to listen to music from their mobile device?
The next smartphone you buy may be compatible with USB-C audio, even if it retains the “normal” 3.5mm jack. Which means more USB-C wired headsets are coming soon, because that’s how it works: Add support for something and companies will start making it. However, the use of the new audio jack raises many doubts and questions, how this experience will differ from the one we have had over the years.
The port is new, the details are the same.
Any type of audio content can be played on our smartphones thanks to the well-coordinated work of a number of special details. Going from 3.5mm to USB-C won’t change anything in this regard. However, the details themselves can change dramatically.
To convert your smartphone files into sound, you need a D / A converter, an amplifier, and speakers. The speakers vibrate to create a wave that affects our eardrums, and the work of their moving parts is possible due to electromagnetism. This wave corresponds to what is called an analog signal, and the varieties of this signal are sounds of different pitches. Then, the wave nature of the signal makes the speaker vibrate, this vibration generates waves that are sent to our eardrums, which, in turn, vibrate in our head, producing sound.
Files on your smartphone or files transferred over the internet are digital in nature. This means it’s just a bunch of ones and zeros put together so the computer can read them and know what to do with them. Digital files, by themselves, do not have any wave nature that allows speakers to produce sound. Therefore, we need something to turn one into another.
Complex algorithms are used to take audio recorded in analog format, convert it to a digital format, such as an .mp3 file, for storage on a computer, and then convert it back to analog for playback. The data has to go to a DAC to convert to the desired waveform and then to an amplifier that makes the wave strong enough to work in headphones. Scientists and engineers use a variety of tricks to “create sound,” but the process described is necessary for all phones, portable audio players, and all speakers.
There are two ways to send audio through the USB port, you guessed it: digital and analog. Analog audio can be converted to your smartphone’s onboard amplifier and DAC and then routed through the port to passive headphones or an adapter. For this to happen, the device must support what is called analog audio operation, in which case the headphones or adapter are just one signal conductor.
If you are using powered headphones or an adapter, the audio signal sent through the USB port is still digital. This means that the DAC and amplifier are inside the headphones or dongle and the conversion is done there and not on the smartphone.
This can cause certain problems. You must ensure that you are using the correct combination of devices. If you have passive headphones or an adapter, your smartphone must support analog audio, and many do not. And the problem is that most dongles, adapters and headphones are not marked in any way for their “activity” or “passivity”, nowhere is it indicated how they are made.
