New Filmmaker needs audio advice
 

I recently posted a few questions on here for advice on what camera to purchase for my needs. I am a U.S. Soldier serving in Afghanistan and making a documentary of my deployment. I am looking at purchasing a wireless system and a boom mic. When it comes to recording what are some of the Basic things I need to be aware of when using an external mic? I am looking at getting a Sony PD170 or a Panasonic DVX100B which ever comes first within my budget. How can I used the other audio channels for this project? What do I need to know? Any other advice would be great.

Chris

There's a lot of information you need to answer those questions, more than can be done in a discussion group message or two. Jay Rose's book "Producing Great Sound for Film and Video" just came out in a new third edition a couple of weeks ago and if you can get a copy it would be a great start for your audio education.

Christopher...

The general rule is that the closer the mic, the better the sound. But there are practical limits as expected.

For wireless, there's interference issues and battery life.

Placement of the mic, and protecting it from wind noise are things to be aware of. And monitoring sound as you're recording is also as essential as looking through the viewfinder.

It takes a few minutes to properly rig a wireless mic & lav, and that could be a problem without an assistant or if you're interviewing several people in a single session. If you're wiring yourself, that's not a problem at all.

You might consider a good camera-mounted mic, depending on circumstances.

I use an AT-4051a and it has given me outstanding results. I've used chatter from people up to 6 feet away without any problems. Of course the ambient noise wasn't too high. I have it set up with a LightWave wind fur. If that's not available, then there are other sources that provide good wind protection for mics.

I chose a cardioid pickup rather than the commonly used shotgun mic. Cardioids have better rejection to the rear, and a more inclusive pickup pattern for two-shots at close range.

Hope this helps, and good luck in Afghanistan.

Hello Chris;

There's a lot to know, that's for sure. Job #1 for you is finding out if the wireless frequencies of the system you intend to buy are legal to operate in Afghanistan. You may be buffered from legal action by the US military, you may not.

I would opt for the DVX100B or Canon XL2 rather than the PD170, but that's my preference. I've just seen more of them in pro use and I own an XL2. It's bigger than the DVX100B, so maybe the DVX100B.

If you will be "run and gun" shooting there, having luxuries such as a boom and boom mic, or even a mixer won't do you much good unless you have someone to operate them for you. Hard-wired or wireless lavs and your camera mic are easier to keep track of. Maybe toss a hand held mic in the kit. The EV RE50 is industry standard.

You'll need a good supply of batteries for the wireless. You'll also need spare batteries and a battery charger for the camera batteries.

I have a small book about location audio that covers a lot of practical info. I wrote it for normal people with as little engineerese as possible. A number of people on this forum have found it helpful.

Regards,

Ty Ford

Hello Chris,
 

Pay more for UHF (Ultra High Frequency) than VHF (Very High Frequency).
UHF systems generally can transmit over a longer distance and are less subject to interference and can even detect a signal through walls since they are no limited to line of sight.
Receivers with two or more antennas (also called diversity systems) provide stronger reception for cleaner sound.
Hope this help.

Actually Sam,

Watt per watt, VHF transmits farther than UHF. (Lower frequencies transmit further than higher frequencies).

I think the "VHF Bad, UHF Good" vibe started when the VHF band got really crowded a number of years ago. Less interference in the more open UHF band was a great thing. Times have changed. UHF can be at least as crowded. You may actually find open VHF spectrum that works as well or better than UHF.

Regards,

Ty Ford

Mostly correct. VHF & UHF are both limited to line-of sight. Either one will transmit through some walls, depending on the material (why would you want to?). VHF spectrum frequently has more transmitters (interference), but that varies, depending on the area. With a clear channel, both VHF & UHF will work equally as well, and are subject to the same limitations, including range.

we obviously went to different engineering schools. :)

Ty Ford

I'm guessing that's a true statement, based on probability. :-)

Subject to the applicable math, there are some formulas that take frequency into consideration. From a *practical* standpoint, and considering how wireless audio systems are used, however, the differences in propagation properties between the VHF & UHF bands can be considered irrelevant; they're both subject to the same basic limitations. Other factors, such as band congestion and channel availability play a far more significant role.

For other examples, when siting our FAA radar & UHF/VHF communications facilities, the equations for radar range, minimum discernible signal (MDS), power density per sq. cm., etc. do not include a factor for frequency other than bandwidth; other factors play a more important role.

It just depends on how deep one wishes to go. When choosing wireless audio systems, keep it simple; the power density between VHF & UHF systems should not be the determining factor.

'prolly so. :)

Ty Ford

about those cameras - I think you need to reconsider. there are several HD cameras available in the same price range - canon and sony in particular. I couldn't tell anyone these days to buy a SD camera, especially since your footage will likely have value in the future. at the very least, shoot 16:9, don't even think of shooting 4:3.

if you were looking at a used camera, thats another story. Even then, there are consumer level HD cameras in the $1k range these days, which shoot to hard disc or memory card. either should prove more reliable then a tape based camera in the dust and vibration you are likely going to encounter.


as for the VX100B ( which shoots real 16:9 btw ) it would be my choice. pretty clean audio preamps. PD-170 not so great, its really a dated camera at this point.