Having been around for less time than the iPhone and iPod, audio specifications remain somewhat blurry.  What we do know about USB and digital audio is promising for future developments.  Here are the Audio specification:


  • Apple claims frequency response: 20Hz to 20,000Hz
  • 3.5mm 4-point TRRS jack for headphone and microphone
  • Audio formats supported: HE-AAC (V1 and V2), AAC (8 to 320 Kbps), Protected AAC (from iTunes Store), MP3 (8 to 320 Kbps), MP3 VBR, Audible (formats 2, 3, and 4, Audible Enhanced Audio, AAX, and AAX+), Apple Lossless, AIFF, and WAV
  • Various bit depths are supported by iOS
  • 16 bit audio supported over USB
  • User-configurable maximum volume limit
  • Stereo speakers (with mono accessibility feature)
  • One microphone
  • Up/Down volume control button
  • Supports some USB Audio Class Devices (depending on current draw) with Apple iPad Camera Connection Kit
  • Dolby Digital 5.1 surround sound pass-through over HDMI with Apple Digital AV Adapter


Digital audio in and out via the dock connector will be vital to professional quality audio on the iPad as well as other future iOS devices.  Being able to attach USB class audio devices via the Camera Connection Kit is exciting news, but is only the first step towards high quality audio.  We hope that Apple will add a highly configurable digital port to the dock connector (who knows, maybe it’s already there) that supports clocking and protocols like I2S.  That way hardware developers would be able to implement high end audio converters without the problems associated with USB audio, like clocking.   There are some rumors going around about adding Thunderbolt technology to the 30-pin connector but we will have to wait and see.


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One Response to “Tech Notes: iPad Audio Specifications”

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