How to use dual Sennheiser G3’s with a DSLR

A reader had these questions about using 
dual wireless mics with a DSLR:

I am interested in purchasing two of the Sennheiser G3 mic systems. I have done so much research and it seems if I need quality audio then they are the cheapest I can get for excellent quality.

I will be conducting interviews with these two systems but I am a bit confused to how I set up two systems into one DSLR (I have a Canon T3i) camera.

Is there some type of audio splitter I need to purchase that plugs into the camera?

Also, is there a shoe mount that will let you mount two transmitters. I don't want to spend all this money and then have one transmitter fall and break.

Thanks for your help!

Here's my reply:

Many people would agree with your choice of the Sennheiser G3 wireless systems – they provide great audio and are very durable so they should be a good investment for years. Just be sure that you actually need to be wireless. You can get better quality for less cost with wired microphones. 

Assuming you do need to mount two wireless systems, there are several cages that will give you many mounting locations. Here's a link to a review I did for the one that I use. 

However, I would not recommend plugging the output of the G3's directly into your T3i. There's no way to monitor the audio in the T3i other than to see if the meter is bouncing.

If you're going to the expense of a double G3 system you need to record the audio with a decent recorder.

While Zoom recorders are the choice of many DSLR producers, I've been using the Tascam DR-40 lately and it's an amazing recorder for the price.

The G3's will come with an XLR cable so you can plug them directly into the DR-40 and record each mic to its own track.

The Sescom LN2MIC-ZMH4-MON 3.5mm Line to Mic 25dB Attenuation Cable will split the headphone output of the DR-40 perfectly for monitoring and feeding the T3i.

Plug the male 1/8" stereo connector into your T3i and plug your headphones into the female 1/8" connector. Now you can monitor both mics while feeding clean signal to your camera for a backup track – and each mic will still be on its own track.

Set the level on your T3i 6db below the level on the recorder and it will act as a safety track in case there's a sudden extra loud peak from one of the G3's.

So, the signal flow would be G3 > DR-40 > Sescom splitter > T3i. The end result will make the most of those beautiful G3's and give you great tracks to work with in post production.