[Richard Crowley]

Yes. Regardless of whether it is a female (input) or male (output) connector, all the connectors are wired with the shield going to pin 1. And then all the pin 2 wired together. And all the pin 3 wired together. That is exactly the same whether the next connector is 1 inch away or 100 feet away. It really is that simple. Quite similar to wiring hot, neutral and safety ground to electrical mains outlets.

Note that pin 1 (and pin 3) appears to be on the “opposite” side of a male vs. a female connector. Always double-check the pin numbers when wiring. There is typically a very small number molded into the plastic insulator to identify pin 1 and 2 and 3.

Of course, you want to use shielded twisted pair cable for this. I would use something like this:
https://www.redco.com/West-Penn-291.html 10¢/ft

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

Likely none of the little plastic “shaver” Zoom recorders are really notable for recording “ambient” sound. Because that requires quite above-average noise floor/dynamic range performance, and none of those little recorders are noted for having very quiet mic preamps. Perhaps the Zoom F4 (4 channel) or F8 (8 channel) recorders have better than average mic preamp performance. But then you also need an exceptionally quiet microphone(s).

You are correct that in general, DSLR cameras have quite marginal audio performance. Perhaps good enough only for a “scratch track” or a “sync track”.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

Yes. Wire the outer shield to pin 1 of all the connectors (male and female).
And pick a color to wire to all the pin 2, and the other wire to all pin 3.
Simple as that.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

It depends of what you are shooting/recording. Are you doing interviews? Concerts? Ambience?

And it depends on what camera(s?) you are using. Why do you think you need double-system sound (separate recorder)? Is whatever you are recording on not adequate for what you plan on recording? Too many unknowns to answer your question properly.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

Yes, typically you can “daisy-chain” the line-level output from a mixer to multiple powered speakers.

You could install a standard wall plate with a male and a female XLR connector at each spot. All wired in parallel with the daisy-chain feed incoming and outgoing. That way you could position the mixer (source) and speakers (destinations) anywhere in the hall with complete flexibility.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

Everything drifts. Every camera, every recorder, every “reference clock”. It is a matter of SYNCHRONIZING the different clocks together so that they are all “on the same page”. Most higher-end pro cameras have internal clocks that are typically accurate enough to go for 4 hours or even 8 hours before drifting too far (more than perhaps 3-4 frames). So it is a matter of taking the reference (in your case your SD 633) and jam-syncing each camera to it before you start shooting for the morning (or afternoon).

It would certainly be advisable to set up all the cameras and jam sync them to the SD 633 and let them run for as long as your recording media holds out. Then go back and analyze the recorded video tracks and see how much drift each camera has. That will give you a reference point how often you need to jam sync the cameras.

The length of the BNC cable is of no significance. It doesn’t matter whether you use a 6-inch cable or a 60-foot cable. And especially when you are using the same cable to sync all the cameras. If you had a cable length of several MILES you might even be a whole frame off. But, of course, the timecode signal wouldn’t survive several miles of cable losses. Electricity travels through cables typically at 70% ~ 80% the speed of light.

You did not disclose what kind of production you are preparing for? Is it “reality” where you are shooting unscripted, unrehearsed, reacting to real-world events? Or do you have the luxury of “slating” each “take”. Even with timecode the slate (and the clap-stick reference) make breaking down and cataloging the clips and editing ever so much easier.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

If you want advice on pro sync gear, ask a vendor who specializes in that kind of equipment. Your “local local pro audio store” does not have the credibility of an industry expert like Trew Audio, et.al.

Furthermore, it is not clear that you need anything more. How do you know that simply jam-syncing each camera to your SD633 each morning won’t do the job simply and easily? Why do you think you need genlock? Why do you think you need wired timecode? People who produce prime-time TV shows with budgets of millions don’t find they need all that. You may be looking for a solution to a problem that you don’t have. Or at least you have not demonstrated a need for.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

What does “multi-cam shoot” mean here? Are you doing on-the-fly, real-time switching between the cameras (as for a live broadcast event or a “live-to-tape” program episode)? Or are you shooting a bunch of cameras in “iso” (where the video from each camera is recorded separately (ISOlated), and then all the camera clips are edited together after-the-fact in post-production processing?

Genlock is more important for live-switching where the cameras must all be in lock-step with each other so that you can switch between them seamlessly. OTOH, timecode is more important for multi-camera, iso production because then the editor knows how all the camera clips correlate with each other.

Some cameras are known to hold their time-sync better than others. Some productions can “jam-sync” each camera to the reference once in the morning and they are good for the rest of the day. Many productions will jam-sync at the start of the day, and then again at the lunch-break (and supper-break for long days). Some makes/models of cameras are notorious for having poor internal clocks and must be synced more often.

This is rather a high-end question and there are many discussions about your very question (and the kind of high-end cameras you are asking about) over on the JWsoundGroup web forum. For example: https://jwsoundgroup.net/index.php?/topic/28186-sound-devices-633-mixerrecorder-timecode-drift/

If you are hiring a professional sound mixer and/or cinematographer, they likely already know the gear and how to sync it together. If you are DIY, you might want to hire a professional for your first few sessions and learn how to use your gear.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

How do you know that the speakers are 2.5 ohm? As you note, that is an extraordinarily low impedance.
What speakers? Make and model.
What is the nameplate rating for impedance? for power?

What kind of speakers are they? What were they designed to be driven from?
If they really are 2.5 ohm, then they are extremely odd-ball

Remember that measuring speakers with a DC ohm-meter is not valid. It wouldn’t be unusual to measure 2.5 ohms DC resistance on a 4 ohm speaker.

Since we know almost nothing about the speakers, we don’t know whether throwing 2 to 4 ohm resistors in series might be a reasonable work-around or not. And we don’t know what the power handling or sensitivity of the speakers are, either.

I agree with you that putting such a very low impedance load on a chip amplifier like the TDA7294 is not advisable.

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Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.

[Richard Crowley]

Neither the Rode Video Mic nor the Zoom H4n are notable for being particularly quiet. Recording ambient sounds typically takes low-noise gear because of the relatively low sound levels being so close to the noise floor of the microphone, and the mic preamp. You didn’t mention what kind of “landscape” you are talking about, but if it is relatively quiet, you may find that neither your Rode Video Mic nor a recorder like the Zoom H4n are quiet enough for that kind of application.

Of course if you could borrow, rent, or buy with option of return, there is no discussion on the internet that can substitute for actually trying it in YOUR situation(s). I would certainly choose the “worst case” (most quiet) situations to test it with. But be prepared to search for microphone and recorder with a lower noise-floor depending on what you are recording.

———————————————————————————
Recording audio without metering and monitoring is exactly like framing and focusing without looking at the viewfinder.