Sound for Video Session: Wireless Hop from Mixer/Recorder to Camera with Sennheiser G3
In this week’s sound for video session we had a chat with Gregg Palmer, one of our friends and fellow sound mixers from Oregon. Gregg explains his experience using Sennheiser G3 wireless systems to send audio from your recorder/mixer to the cameras so that they also record high quality production sound.
Greg discusses the following gear:
Sennheiser G3 Wireless Lavalier System (Be sure to research whether this frequency band can be used in your local area)
Cable to Adapt from G3 Receiver to XLR input for Camera (if your camera has an XLR input)
Cable to send audio from Zoom F8 or F4 to G3 Transmitter and from G3 to camera
Sennheiser AVX Wireless Lavalier Kit (MKE2 Microphone)
Ethics statement: Some of the links above are affiliate links which means that if you click on them and buy, I get a small commission. You don't pay more by clicking these links than if you just went to the retailer’s web site on your own. I use the proceeds to buy additional gear to review and help you improve your sound, lighting, and video. Thanks for your support!
*Added 2 Jan 2017*
Mark Kirchner added additional technical information for those who would like to use this method to optimize the signal from the mixer to the transmitter:
Your guest on your G3 hop video can optimize the signal with a custom cable to turn his transmitter into a hop-transmitter that will receive a "tape level -15 dB audio signal. The wiring on the TX side should not be soldered to the tip of the TRS plug. The transmitter want to "see" a mono "unbalanced" signal, not a L/R signal like your video guest was sending it using stock TRS to TRS mini 3.5 plugs. E.T. designed this cable for me to "sum" the left/right channel(left/right mix-bus) to the G3 transmitter. The audio signal leaves the mixer as L/R unbalanced signal (tape level -15 dB). To use this tape level signal correctly it must be sent (soldered) to the "ring" of the TRS plug. If you like I will make you one for free for your Sound Devices 633 and then you can try it with a G3 TX and RX yourself.
The following are notes from a conversation with E.T. He designed this cable. I know you are not a "soldering guy" and purchase your XLR cables. It will take awhile to understand what I have written. Unity Gain, Reference Level, Gain Staging and Unbalanced/Balanced are concepts that take time, but worth the struggle to put them into the old gray matter. You might find it helpful to draw a diagram of the 2 connectors, using colored pens and different colors for each conductor.
Last, my family roots come from Grantsville Utah. There was a film made about my second cousin Kimball Johnson called "Pigweed Philosopher." Check it out it is about film-making. If you have been to Grantsville, you may have seen the old Victorian house on main street. That's the Johnson house, our family house. I saw you have not been on this sight in a while, so this letter may find you in 2017.
Best,
Mark Kirchner mkirchnersound@gmail.com
PS Thank you for interviewing "The Senator" Mike Michaels!
WIRELESS HOP from the 442 MIXER w/ SENNHEISER G3
Set-up
1. Use the Sound Devices 442 Tape/Mix out (TA3) connector.
2. Tape/Mix Out = -10 dB *
3. Use Custom E.T. Mix-Out Hop Cable**
4. Connect 442 to the G3 Tx
5. Starting recommendations from E.T.; settings for the Tx –12 dB sensitivity.
6. Set the Rx about the same and test.
*The Tape/Mix out of the 442 sends both left and right signals at a –14 dB level if the mixer is set for a "0" dBu reference level. All left channel assignments (channels 1-4 on the 442 mixer) will be “mixed” and output as a discrete “mixed left channel.” The right channel will mix all right channel assignments.
**The E.T. Hop Cable sends a unbalanced, left and right signal to a TRS connector, assigning the left and right signals to a single terminal (ring) on the TRS connector making a “summed mono signal” that the Sennheiser G3 transmitter needs for the proper signal input.
Note; The Sound Devices manual for the 442 mixer lists the maximum output level for the Tape/Mix Out as follows.
Page 24 Tape/Mix Out +6 dBu
Page 26 Block Diagram Inputs and Outputs
The schematic diagram (page 26) displays the Mic / Tape / Line as 0/-14/-40 which should be written as Mic – 40 / Tape – 14 / Line “0” .
A “Tape Level Signal” is normally –10dBu. The designation of “tape level as –14” is based on an “0” dBu reference level. The Sound Devices schematic is based on a “0 dBu” reference level (-14 dBu @ “0” reference level = -10dBu @ +4 dBu reference level).
E.T. WIRELESS HOP CABLE (Sennheiser G3)
This cable was engineered for use with the Sound Devices 442* “mix/tape out” output on the TA3 output.
TA3f Connector
Redco TGS-1 Cable (2 conductors + shield and drain)
TRS 3.5 Mini locking connector
TA3f connector (output)
Pin 1 Ground (Eric used drain wire)
Pin 2 Signal (+) red conductor (Left)
Pin 3 Return (-) clear conductor (Right)
TRS 3.5 Mini Connector **
Tip No Connection
Ring Signal and Return (+ @ -)
Sleeve Ground (drain wire)
Notes:
*The Tape/Mix out of the 442 sends both left and right signals at a –14 dB level. All left channel assignments (channels 1-4 on the 442 mixer) will be “mixed” and output as a discrete “mixed left channel.” The right channel will mix all right channel assignments.
**The E.T. Hop Cable sends an unbalanced, left and right signal to a TRS connector, assigning both left and right channels to a single terminal (ring) on the TRS connector making a “summed mono signal” that the Sennheiser G3 transmitter needs for the proper signal input.
Sennheiser G3 Wireless Special Pricing
One of the first wireless lavalier systems I ever used was the Sennheiser G3. These kits are everywhere in the independent and documentary filmmaking world. And there's good reason for that: They're solid and reliable. Yes, you'll need to read the manual and learn how to use them and set up them up, but once you've got that down, they work reliably, are well built, and have some nice features like locking 3.5mm plugs.
These transmit an analogue signal. This is what most of the pro-level wireless systems do and there are some advantages to that. First, you're not sharing the rather overwhelmed 1.4GHz band with all the WiFi, Bluetooth, and other consumer electronics enabled devices out there (mobile, cordless phones, etc). Also, there are potentially distance benefits as well. But of course, you do need to buy a device with the right frequency band for your region so if you do look seriously at these, you'll want to research which band is suited for your region of the world. For those in the US, B&H is recommending models which transmit in frequencies below 600MHz. And the FCC has some FAQs here.
B&H has several kits at the regular price but with some bundled items which make for a good deal: a $100 B&H gift certificate and a case similar to a Pelican for the kit. I'm told that these bundle deals last through the end of September.
There's a dizzying array of model numbers, but here's the basic G3 kit with the ME2 lavalier microphone and a coldshoe mount receiver.
And here's the same G3 kit with the ME2 lavalier but which also includes an XLR plugon transmitter for handheld mics.
