Jump to content

Powering a Zaxcom QRX or RS900S from a Red One


Mark Orusa
 Share

Recommended Posts

I'm doing sound for a documentary and I'm considering using a QRX or RS900 on a Red One as camera hops. I would like to know if anyone has experience powering them from a Red One specifically. How well does it work (if at all), how do the camera batteries fare, and what do camera operators think about it?

 

Are there better options than camera powering? Or should I just go with a scratch track from an IFB like a Lectro IFB-R1a or Zaxcom ERX? I'd like to provide my two track mix to camera for editorial and there will be situations where I don't want to tether.

 

I've read the thread about externally powering a QRX:  I don't do wireless hops very often so I don't know if it's worth my time and money to invest in a dedicated external power solution for the QRX.

 

Mark O.

Link to comment
Share on other sites

When I used to tether from my Sound Devices 442 into Red One I got great results. Ever since I bought my Nomad the camera clips at -4 to -6 below 0 dbFS. I've interfaced my Nomad with other cameras like the Sony EX-3 without issues, so I assume it's the Red.

 

Unfortunately, the XLR outs on Nomad are only adjustable from 0 dBu line to -10 dbu consumer to -35 dbu mic. If I could lower it by 6 db or so maybe I'd get a decent track into camera. The camera jumps in 10 db steps, so that doesn't help either.

 

Mark O.

Link to comment
Share on other sites

This is off thread a bit, but any thoughts as to why I'm getting distortion when cable-tethered to Red One from Nomad? It's only when I'm within 6 db of the max in. I can hear it clip in the 5 pin return and headphone jack, and it's not the camera output. It's audible on the camera's audio tracks when you ingest to editing software.

 

I'm guessing that it's because the camera only allows +18dbu in and Nomad can do +20dbu out. Page 132 of the Red One Manual:

Reference signal level for Line inputs is 0dBu / 0.775 volts RMS / -20dBFS when operating at 0dB Input Level. The maximum input signal that can be applied before the onset of input signal clipping is +18dBu / 6.5 volts RMS / - 2dBFS. This provides a guaranteed minimum of 18dB of input signal headroom above reference, in combination with maximum Signal to Noise Ratio for the resulting 24-bit digital recording. 

 

Mark O.

Link to comment
Share on other sites

I would suggest using an ERXTCD and feeding one track of audio for reference (mono mix of everything) and timecode. The RED One loses timecode every time the battery is swapped so always having timecode being fed to it is a huge time saver for production. Personally, I wouldn't bother with a 900S or QRX seeing as how it is simply a reference.

Production Sound Mixing for Television, Film, and Commercials.

www.matthewfreed.com

Link to comment
Share on other sites

I think the Red One, and cameras with similarly unreliable TC, was part of the motivation for the ERXTC. I have not done it because I just have not shot on a red one since I got my ERXTC. When the ERXTC was first announced, that was what immediately popped in my head. On scripted drama I normally put a G2 scratch hop and a SB-3 on the red. The ERXTC is half the size, lighter and gives better results. As for powering off the camera, no problem. I had a power cable made because the Red uses a DC out that is not the more common Hirose (surprise). I put a RX900S on there, before the QRX100 was out. I did it sending 2 tracks of audio, and I made a cable coming out of the RX900S that was one track of audio, and TC (over the 2nd Zaxcom audio channel). Most of the jobs that really wanted primary audio on the Red were tamer interviews on sticks, so I cable in and monitor the camera. It is true that the Red will clip sooner than most other cameras out there, so you have to be careful. That's why a lot of people prefer to put a reference track and some way to keep TC locked. I like providing some sort of scratch audio for playback, and it may help post sync everything.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...