Yes, the iPhone has limitations when it comes to recording professional audio, but even still, an iPhone with the right apps and hardware is fully capable of making suitable tracks for an album. After all, how many albums were recorded on 16-bit/48kHz ADATS that found their way into so many studios?
Unfortunately Apple doesn’t post very much technical data, however we do know the following iPhone Audio specs:
- Apple claims frequency response: 20Hz to 20,000Hz
- Studio Six Digital tested low frequency roll-off or 24dB/octave @ 250 Hz for wind/pop reduction on microphone (dock connector line input remains flat)
- 3.5mm 4-point TRRS jack for headphone and microphone
- Support for MP3, MP3 VBR, AAC, Protected AAC, Audible (format 2,3 and 4), Apple Lossless, AIFF, and WAV
- Various bit depths are supported by iOS, the bit depth supported by hardware is unknown, probably 16 bits
- Audio line in supports up to 48kHz (1st gen was 8kHz)
- Up/Down volume control button
- One speaker
- One microphone
- Stereo audio line in pinned out on dock connector (iPhone 3GS and below only)
- Stereo audio line out pinned out on dock connector
- Dock connector USB pins do not support USB Audio Class devices (unlike iPad with Camera Connection Kit)
As you can see, this leaves questions like SNR, hardware bit-depth, crosstalk, actual frequency response and noise unanswered. For high quality audio using the line-in on the dock connector, an iPhone 3GS or below must be used. This poses questions about the future of high quality audio recording on iPhone 4 and subsequent models. If Apple plans on supporting USB Class Audio devices (like iPAD), we see this as an excellent opportunity for hardware developers to use higher quality 24-bit audio codecs.
- iPhone (1G, 3G and 3GS as well many other Apple producst) Dock Connector pinout)
- iPhone headset TRRS pinout
- Studio Six Digital
- Faber Acoustical Audio Input Options (WITH FREQUENCY RESPONSE PLOT)
NOTE: THIS POST WILL BE UPDATED AS SPECIFICATIONS CHANGE/BECOME KNOWN.