iPhone 4 - feed external audio into it for video recording ???

Both the audio jack and the dock connector on the iPhone can handle both audio input and output, but whether it's compatible with the video recording function is anyone's guess.

Matt

There are a number of options on the 3GS. Blue Mikey makes a very nice stereo mic that plugs into the doc connector. They're coming out with a new improved model in August that has a stereo audio input and USB connector for charging while recording. This one also has improved preamps to handle higher signal levels without distortion. Belkin TuneTalk is a similar design, but the mic isn't as good.

But there appears to be no option for the iPhone 4. The stereo audio inputs were removed and replaced with USB inputs. But the iPad camera connector doesn't work on the iPhone, so current USB mics (like the Blue Yeti) do not work on the iPhone. This is likely due to the power required by USB devices and the limited battery capacity in the iPhone. A real pitty.

See my Post at: http://www.centrance.com/forum/viewtopic.php?f=15&t=291

See info on MicPort Pro at: http://centrance.com/products/mp/

REQUIREMENT & PROBLEM -1 Get a high quality analog or digital audio signal into the iPhone 4 via a MicPortPro & XLR Mic.
1a.The analog audio feeds in to the TRRS 3.5mm jack on the iPhone 4. This can be done now.
1b.The digital audio feeds into the iPhone 4 dock connector. This cannot be done now.

POSSIBLE 1ST GENERATION ANALOG SOLUTION -2:
1a. Possible "Non-official"/"Not-tested" Analog Solution.
The idea is to bring an analog mic signal into an iPhone 4 and simultaneously bring a digital mic signal into a laptop such as the Apple MacBook Pro 15. The MicPort Pro headphone signal is split 2 ways with a TRS Y stereo adapter to the iPhone 4 and to also use a pair of headphones for realtime monitoring. Component 1 is an Adapter from KV Connection (with -22db attenuation) used to interface an Apple iPhone 4 3.5mm female TRRS connector to a Line Level Signal source (i.e. 3.5 mm Analog Headphone TRS Female Jack on the CEntrance DAC MicPort Pro XLR to USB - Component 2 . The MicPort Pro is connected by an USB cable to a laptop such as the Apple MacBook Pro 15 – Component 3. The MicPort Pro is connected to an XLR Microphone such as the Rode NTG-2 (requires phantom power or internal battery power) or similar XLR Mic – Component 4) If the MicPort Pro was self powered / rechargable we could take the laptop out of this equation which also provides power to the MicPort Pro via the USB cable.

In addition to the $149 MicPort Pro, here are the cables required:

* A Y ADAPTER SHORT CABLE WHICH PLUGS INTO THE iPHONE 4: The $24.38 KV Connector. iPhone 4 Adapter 3.5mm 4 conductor TRRS MALE Jack (into iPhone 4) splits to (a) a 3.5mm TRS FEMALE Headphone Jack (to monitor iPhone 4 audio playback via headphones) and (b) a 3.5mm TRS FEMALE iPhone 4 Microphone Jack with built-in -22 dB Line-Level Attenuator. This is a -22 dB attenuated LINE LEVEL connection that takes analog audio output from the MicPort Pro headphone Jack. You can also use this Line level connector to import music or sound from a recorder like a Zoom or a Laptop or other line out device from a stereo. http://www.kvconnection.com/product-p/k ... rs-a22.htm

* A Y ADAPTER SHORT CABLE WHICH PLUGS INTO THE FEMALE HEADPHONE JACK ON THE MICPORT PRO: The $7.90 KV Connection Y Cable is a 3.5mm Mini Stereo MALE Jack (into headphone jack on MicPort Pro) split to Dual Mini Mono FEMALE Y-Cable 6 Inch long ... one can be used to realtime monitor realtime ( 0 latency) the analog mic signal and the other connector connects via a cable (with 2 male jacks) to the line level female connector in 3 above. http://www.kvconnection.com/product-p/t-y-mps-2mf.htm

Hoprefully forum readers can try this out and report their results back here.

First, buy the $20 KM-IPHONE-2TRS iPhone 4 Y adapter to plug in an external Mic and Headphone. http://www.kvconnection.com/product-p/km-iphone-2trs.htm

Second, I would use Dual System Audio. Record Scratch audio via iPhone 4 internal mic & record Production audio via a Zoom H2 or Zoom H4n portable audio recorder.

You would sync up the Scratch and Production audio channels via PluralEyes http://www.singularsoftware.com/pluraleyes.html The mono analaog audio recorded on the iPhone 4 internal Mic / external Mic input cuts off below 200 Hz and has other fidelity issues.

Third, I would invest in a battery powered Rode NTG-2 Mic Kit with the excellent Pearston LMT00 Shockmount (to reduce handling noise) versus the lower end Rode VideoMic with flimsy Shockmount. The NTG-2 / Shockmount Kit is $269 at B&H. http://www.bhphotovideo.com/c/product/481528-REG/RodeNTG_2_Condenser_ShotgunMicrophone.html

Fourth, You should also invest in a good deadcat fuzzy to reduce wind noise and a boom pole when shooting outside.

Personally, I use a Zoom H2 with a $25 ATR-3350 Lav Mic and a $50 ECZ-990 Zoom Mic feeding into a Y cable on the H2 for 2 channel audio and sync in PluralEyes with the scratch audio off my iPhone 4. The 2 battery powered Mics mentioned above are real “portable” also.

None of the solutions are adequate. Getting a mic into the iphone4 3.5mm jack works, but is significantly inferior to what is already supported on the 3GS for two reasons: its mono, and it has a steep 200hz bass roll-off which makes it pretty useless for music recording (although fine for voice).

Apple - we want the audio inputs on the 3GS back - please. I would really love to be able to use the new Blue Mikey with my new iphone4, and bought them assuming I could only to have to find out through discussion forums like this that I wasted my money. I have numerous audio recording apps on the iphone4 that are really great - but can't get any input into them - so those are a waste too. This is very disappointing.

I also have a Zoom H4n, but would prefer to use the iphone4 and Blue Mikey because, 1) the recording software on the iphone is much better (e.g., Multi-track), 2) the new Blue Mikey is a better mic, 3) I have my phone with me all the time, I don't want to have to carry the Zoom H4n around too.

I suppose eventually someone will come up with a USB stereo mic that works with the iPad and provides its own power through a battery. Maybe Apple will approve such a mic and enable the USB inputs for some supporting application. But this will never be as simple, economical or as good as the combination of the Blue Mikey with the iphone 3GS.