"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Some 2018 MacBook Pro Owners Experiencing Crackling Speakers
The crackling appears to occur spontaneously during audio playback on both 13-inch and 15-inch models, based on a handful of videos shared by customers. As with many crowdsourced issues, there are a lot of variables involved, making it difficult to pinpoint exactly what may be causing the problem.
Some customers appear to experience the issue while playing music in iTunes, while others are affected when using GarageBand, or playing a YouTube video. Some users also hear the crackling when running Windows via Boot Camp. It's unclear if the crackling is limited to specific volumes or frequencies.
MacRumors forum members have speculated about possible causes, including radio interference due to a lack of shielding, audio drivers, and the T2 chip.
A few years ago, some customers experienced similar crackling from the built-in speakers on the 2016 MacBook Pro, oftentimes when running Windows via Boot Camp. The crackling was so loud that it often permanently damaged the speakers, resulting in the MacBook Pro needing to be repaired or replaced.
Within days, Apple acknowledged the issues in a support document, and released updated audio drivers for Boot Camp with a fix:
If you installed Windows 10 using Boot Camp Assistant before November 25, 2016 on a MacBook Pro introduced in October 2016, it's important that you install the Audio Driver Update for Boot Camp using Apple Software Update for Windows to avoid issues with your speakers.The speaker issues with the 2018 MacBook Pro don't appear to be as dire, or nearly as widespread, but enough complaints have surfaced that we wanted to bring some attention to the matter in the interest of those affected.
At least one user claims the issue may have been fixed in the latest macOS Mojave betas, which is unconfirmed. Another user claimed that Apple engineers are looking into the matter. Apple did not respond to a request for comment.
Of course, in a production run of millions of new MacBook Pro units, a small percentage may have defective speakers, but this does appear to be an actual issue that hopefully can be or has been addressed in a future software update.
If you are affected by this issue, we recommend contacting Apple Support. In the meantime, some users have shared potential workarounds, such as resetting the System Management Controller and NVRAM, disabling Hey Siri, or simply rebooting, but these solutions may not be ideal or work for everyone.