Am I screwing myself?

[Mike P.]

I believe 192kHz sampling-rate is gross overkill for motion picture work, except in very unusual sound effects situations. 48K is what nearly every movie & TV show sound crew uses, and that goes for anywhere from $200 million movies to $50 web videos.

Why would the sounds need "heavy equalization work"?

You actually said what I wanted to hear; the only time I'd need 24/192 would be for sfx which is rare for me. 9 times out of 10, I'll be using the pre-synced audio that's fed to the camera from the 702 (which I think is recorded at 24/96 on most cameras). The only time I plan on having to manually sync (assuming I don't get a timecode-capable recorder) is when I couldn't be tethered to the camera, which is somewhat rare as well.

Similarly, if I find I'm constantly needing more than 2 channels and having to rent a mixer, I'll most likely buy one at that time (or sell the 702 and look more closely at the 744t). I know recorders aren't that well layed out for doing on-the-fly adjustments, but I don't plan on riding the levels all that much on location simply because I'm not that good yet.

A used 744t is roughly three times the cost of the used 702 I'm looking at... Maybe I should rent a 702 to see how well it plays the way I intend to use it.

UPDATE: Passing the 702's audio through the TA3-to-CameraXLR is gonna be mono, isn't it? Like even if I fade one of the 702's channels 100% left and the other 100% right, they're gonna be combined when I go out the 702's TA3 to the camera's XLR, aren't they? That's kind of bogus... Which means I'd need to use the 1/8"/Tape-Out if I wanted to keep the channels separate, but how long can an 1/8" cable run for before interference and just general robustness starts to decline? 10ft? Lame.

...Are TA3's mono or is there a Y-cable that goes from TA3 to XLR-left and XLR-right cable?

 

[Marc Wielage]

Passing the 702's audio through the TA3-to-CameraXLR is gonna be mono, isn't it? Like even if I fade one of the 702's channels 100% left and the other 100% right, they're gonna be combined when I go out the 702's TA3 to the camera's XLR, aren't they?

No -- there's two TA3 outs, left and right (channels 1 & 2). Manual available at this link.

Which means I'd need to use the 1/8"/Tape-Out if I wanted to keep the channels separate, but how long can an 1/8" cable run for before interference and just general robustness starts to decline?

The 1/8" output is stereo, but I think it's a -10dB line level out intended for short runs to wireless transmitters and so on. I wouldn't run a cable longer than 6 feet or so. Better yet, use the mini-XLR outs and run those directly into your camera. If your camera doesn't have XLR ins, then get an adapter like the Beachtek to step it down to the right level.

Be warned that without timecode, there's a chance the sound sync will drift with picture. As long as you can manually pull it up in editing, you're OK, but it's dicey.

 

[Mike P.]

Thanks Marc, I'm re-reading everything now.

Do you think going from A/D conversion, then D/A conversion to TA3/miniXLR outs will make a noticeable sound quality difference? Bare in mind the camera will only be recording at 16/48 (or whatever it's max is... definitely not 24/192 though).

Also, isn't line-level (-10db) ideal? Like it wouldn't use the camera's pre-amps and audio levels could be adjust to keep it from peaking (on both the 702's outputs AND the camera's inputs.)

Sidenote/rant: How is audio drifting still a problem? If I record audio for 10mins and record video for 10mins what would cause them to drift apart? And wouldn't drift be less likely if I were pumping it directly into the camera from the recorder? I'm not a sound guy and really don't understand how this issue happens... And would would be the difference between going through a mixer (non-timecode, but still doesn't drift) and going through a recorder (without timecode)?

 

[Marc Wielage]

Do you think going from A/D conversion, then D/A conversion to TA3/miniXLR outs will make a noticeable sound quality difference?

Real world? No. There's going to be far more noise on location then there will be to worry about an additional A/D -> D/A stage.

Also, isn't line-level (-10db) ideal?

With a pro system, you'd want real line level -- +4 balanced. -10 unbalanced leads to hum and noise, especially on a cable more than 10 feet.

Sidenote/rant: How is audio drifting still a problem? If I record audio for 10mins and record video for 10mins what would cause them to drift apart?

If camera and sound recorder don't have a common reference, then the sync for sound recorder and camera are coming from a different clock crystal. Without timecode and accurate sync, drift will happen. It's just a question of how long before it happens. With short takes, it shouldn't be a gigantic issue, assuming common frame rates.

If you're just doing audio on the camera alone, there's no issue. But the audio sections of most cameras are pretty piss-poor. You're almost better off recording on a separate recorder and then marrying them together in editorial. I would only use the camera sound as a scratch track.

When in doubt, do a ten minute test prior to your production, do a sync clap at the head and tail of the scene, then load the files into your edit system and make sure the sync is good all the way through. Workflow tests are very important with new gear, especially if you can't use timecode.

 

[Mike P.]

More answers, more questions.

Could I use an external timecode generator with the 702 and RED1/Epic/Scarlet?

Conversely, does RED1/Epic/Scarlet have a built-in TC generator and if so couldn't that be pump to the 702 non-T to maintain sync?

The manuals I got seem to use "702" and "702T" interchangeably (as in, one manual for both devices), so I'm unsure whether the 702 can accept TC from an external source and I'd rather know for sure rather than assume.

 

[Marc Wielage]

Could I use an external timecode generator with the 702 and RED1/Epic/Scarlet?

No timecode input on the 702. There's a good one on the 702t (the "t" standing for timecode), but it also has an extremely good Ambient timecode generator built in.