It's been several years since Apple had the "courage" to get rid of the headphone jack. While the decision was quite controversial, other manufacturers eventually followed suit, and the 3.5 mm headphone jack has now been removed from most smartphones.

With the 3.5mm jack on its way out, the only options left for users are USB-C and Bluetooth. USB-C looks like a viable replacement for the headphone jack on paper, but how does it actually stack up in the real world? Let's examine the good and bad parts of USB-C Audio.

What Is USB-C Audio?

USB Type-C is the reversible USB connector that started appearing in devices since the USB Implementers Forum (USB-IF) finalized its specifications in 2014. USB-C has increased in popularity over the years, and most modern smartphones, laptops, and tablets have a USB-C port. USB Type-C is designed to make life easier for users (they only have to worry about one type of cable and port) and make production easier for manufacturers (as they don't have to support so many different connectors).

USB-IF published the specifications for USB Audio Device Class 3.0 in 2016 with the aim to "establish USB Audio over USB Type-C as the primary solution for all digital audio applications, including headsets, mobile devices, docking stations, gaming set-ups, and VR solutions."

USB Type-C Audio was created to standardize audio output using USB Type-C. This would allow the USB port to serve as a replacement for the 3.5mm audio jack, and device manufacturers would be able to send and receive power, transfer file data, output video, and output audio, all using one single port. According to USB-IF, this would allow thinner, longer-lasting, and potentially waterproof devices.

Although it serves the same purpose, USB-C audio works differently from a headphone jack. A 3.5mm headphone jack outputs only analog audio, with the processing achieved using a digital-to-analog converter (DAC) housed within the smartphone. USB Type-C will transmit digital audio instead, leaving it up to your headphones or other listening device to convert this data and amplify the sound. USB-C can also send analog audio output like the headphone jack, as long as it is implemented in the port and your phone has a DAC for wired audio.

What Are USB Audio Protocols?

Three USB-C audio protocols (or classes) allow a USB device to function as an audio peripheral. These classes work with all types of USB connectors.

• USB Audio Class 1.0 (or at least a subset of it) is supported natively by all major operating systems, including Android smartphones running 5.0 Lollipop or newer. UAC 1.0 is limited by USB 1.0 speeds (12Mbps) but supports high-resolution audio at a 96kHz sample rate.
• USB Audio Class 2.0 introduced faster transfer rates with support for High Speed USB 2.0 (480Mbps), allowing for low latency audio transfer, higher sample rates, and more bandwidth for multiple channels. It also increased audio resolution to 32-bit/384kHz at the cost of higher power consumption.
• USB Audio Class 3.0 mainly brought improvements in power usage and added support for features such as active noise cancelation, hot word detection, and user-defined EQ, to name a few.

UAC 1.0 is still the most common audio class by far, and most USB audio devices use this specification even though it is outdated. Android first introduced UAC support with Android 5, and most modern smartphones with a USB-C connector support the latest standards, while iOS supports UAC 2.0.

The Audio Adapter Accessory Mode is another protocol related to USB audio. This mode allows the connector to transfer analog signals similar to the 3.5mm jack. It works by repurposing pins on the port to accept passive audio signals. As mentioned earlier, this mode requires an internal DAC rather than an external one.

The Good Parts of USB Type-C Audio

Since USB-C audio doesn't require a DAC in the phone, manufacturers can remove the internal DAC and free up precious space inside devices. This also means that the DAC can now be moved to either a headphone or an adapter. Buyers can choose the product that offers the sound they want instead of being stuck with a generic and often inferior internal DAC. Another benefit of an external DAC over an internal one is that it potentially reduces the interference posed by power supplies and processing hardware inside the device.

Also, by ditching the internal DAC, there will be less processing for the phone, potentially improving battery life. However, any adapter for analog headphones must include a DAC, which will need to be powered by the phone.

The fact that USB Type-C can support multiple digital inputs at one time means that adding inline remotes that work with all devices will be a lot easier, too. It makes it possible to use hot words, such as "OK Google" or "Hey Siri," over a pair of USB-C headphones. Also, USB-C Audio supports features such as active noise cancellation, surround sound, and digital effects.

The Bad Parts of USB Type-C Audio

USB-C Audio isn't perfect by any means, and there are several issues with this new specification.

For one, using a USB-C headphone means that your charging port has to double as an audio listening port, making it prone to more wear and tear. This also brings up the issue of charging and using wired headphones simultaneously. This question first came up after the announcement of the iPhone 7, and there were solutions that allowed you to use your headphones and charge—but only in a setup involving three separate cables, which is far from pretty, clean, or convenient. You still need a similarly unwieldy setup to charge your phone and listen to music simultaneously with USB Type-C headphones.

Compatibility issues are another bad part of USB-C audio. There is no way to tell that a USB-C headphone will work with your phone just by looking at it. So, you may spend a lot of money on a new set of headphones to find out that they don't work with your phone or the volume buttons aren't functional. If you are buying USB-C headphones, buy a pair with a DAC to ensure compatibility with all your devices.

What about using adapters to connect your old analog headphones to your phone's USB-C port? In that case, you will need an adapter that includes a DAC, and those tend to vary dramatically in quality. The lower-quality adapters will be cheap, while a decent one may set you back almost as much as another pair of headphones.

The 3.5mm jack has been such a mainstay throughout the decades because it is simple. There is no charging or additional cables. You simply grab your headphones, plug in, and you are ready to listen. Simplicity was the key to its success. USB Type-C Audio complicated that process and ended up pushing people toward wireless headphones.

USB Type-C Audio vs. Bluetooth

Analog jack aside, the main competitor of USB Type-C Audio is Bluetooth. Bluetooth 5.0, released in July 2016, quadrupled the operating range, doubled the speed, and increased the data broadcasting capacity of Low Energy (LE) devices eight-fold. This makes it a worthy replacement for the abandoned 3.5mm jack, but it is not without its limitations.

Generally, Bluetooth headphones do not sound as good as similarly-priced wired headphones. They are also less durable and reliable. However, the pros still outweigh the cons, and anyone who isn't a strict audiophile would be well-served with a good pair of Bluetooth headphones.

You can find more detailed information in our comparison of USB, standard (3.5mm), and Bluetooth headphones.

USB-C Audio Is Not the 3.5mm Jack Replacement We Hoped For

While there are benefits to the technology, USB Type-C Audio is nowhere close to being the 3.5mm headphone jack replacement it was promoted to be. Factors such as compatibility issues, lack of substantial improvement over the 3.5mm jack, and the improvement of wireless audio over the years have resulted in minimal adoption by users and manufacturers.

However, the headphone jack doesn't seem to be coming back to smartphones anytime soon, so we're stuck with USB-C audio for better or worse. Hopefully, future upgrades to USB-C Audio bring much-needed improvement, and we could get cheaper and better headphones/adapters in this category.