The redesigned 2021 MacBook Pro models mark the return of the HDMI port, SD card slot, and 3.5mm headphone jack. The company explains that the new and improved headphone jack is not just for regular wired headphones, it also supports high-impedance headphones.
High-impedance headphones require more power to deliver high-quality audio with less distortion at high volume. Discussing the new 2021 MacBook Pro models, Apple’s Product Manager Shruti Haldea detailed that the upgraded 3.5mm headphone jack support studio quality headphones and automatically detects the value ohms to modulate the current.
The headphone jack got an upgrade it’s not just a 3.5mm headphone jack anymore. It now has support for high impedance headphones. So the jack will automatically detect the impedance of the headphones when you plug it in and modulate the current delivered to the headphones based on the impedance and so you’ll get the right output on your headphones. So this is great for folks, for audio files using high impedance headphones they no longer have to have an external amplifier. – Haldea said in Same Brain podcast #50
2021 MacBook Pro users can directly connect high-impedance headphones in 14-inch and 16-inch models
On the dedicated support page, Apple details that the high-impedance headphones can be directly plugged in 14-inch and 16-inch M1 Pro/Max MacBook Pro models. The new headphone jack removes the need for an external headphone amplifier.
When you connect headphones with an impedance of less than 150 ohms, the headphone jack provides up to 1.25 volts RMS. For headphones with an impedance of 150 to 1k ohms, the headphone jack delivers 3 volts RMS. This may remove the need for an external headphone amplifier.
With impedance detection, adaptive voltage output, and a built-in digital-to-analog converter that supports sample rates of up to 96 kHz, you can enjoy high-fidelity, full-resolution audio directly from the headphone jack on your MacBook Pro. – Apple
The 2021 pro notebook also features new speakers and microphone systems which are called the best audio system in a Mac ever by Apple.