After 30 hours this weekend just fumbling around trying to get my Sennhieser mic system to work with my iPhone I spent A LOT of of time this week researching, testing, and finding out a way to get my Sennheiser wireless microphone bodypack to work with the iPhone.
Just plugging the bodypack in would cause the mic input on the iPhone to go crazy, so after seeing what the voltage dropped to with my new iPhone headphone test circuit board (See gallery Below) and one resistor and capacitor latter i got it working.
Now did i stop there, HELL NO, I decided to make a breakout box that allowed me to switch from a straight pass through to Mic/Line in mode. Another set of switches allowed me to switch between regualr mic mode and a mode that added the resistor and capacitor to let my sennheiser wireless mic work.
I also made a Breakout cable that splits the 4 pin iPhone connector to a headphone and a mic jack. The box also has a past through connector. All the parts were bought at Mouser or Radioshack.
The Breakout box took 7 hours to mod the box, wire up the switches, make sure i wasn’t making any mistakes and then finish it. I had 2 “uh-ohs” putting it together but i fixed them. I love this box, i think it came out VERY nice and is very clean and nice looking. Its some of my tightest and neatest wiring to date.
I’m going to edit this post sometime in the next week or so with a schematic of the breakout box and maybe part numbers.