View Full Version : Need sound advice for my first HD project please!


Shawn Whiting
October 11th, 2009, 02:58 AM
Hey everyone,

So this project will be a promotional video for a local college, lots of shooting, in terms of audio probably lots of interviews, classroom situations, walking and talking shots, etc. Its also important to know that I will likely be solo shooting this most of the time, although i could call on some friends to hold the mics or monitor levels for harder days.

The audio equipment i currently have:
The Azden SGM-PDII short shotgun that came with my HMC150 from B&H
Azden | SGM-PDII On-Camera Short Shotgun Microphone | SGM-PDII (http://www.bhphotovideo.com/c/product/497310-REG/Azden_SGM_PDII_SGM_PDII_On_Camera_Short_Shotgun.html#reviews)

A H4N zoom recorder. and the on board mic's of the HMC150.


Seems to me that some wireless lavs would work best to round out my beginners package. But since i will be filming around a college perhaps this may not be a great idea as there could be a lot of interference? I really know nothing about wireless sound, or maybe i want wired lavs? If someone could run me through the key elements and options i should look into when checking out wireless or wired lavs that would be great. Or perhaps there is something even better?

I have very limited experience in sound, so please feel free to explain things as if speaking to a total beginner. Thanks!

- Shawn

Nathan Moody
October 11th, 2009, 10:55 AM
Shawn, welcome to a deep and confusing world. :) The list of preferences for audio quality are usually, but not always:

- Boom mic from above
- Boom mic from below
- Wired lav
- Wireless lav
- Mic on camera

My experience, which will probably sync with many others':

- Wireless never sounds good as a boom mic aimed at the throat or chest, due to where you put the lav.
- Don't overlook the possibility of using WIRED lavs. Good step from standard mics without needing to go wireless. WAAAAY cheaper, no dropout/interference issues.
- Just because they're called boom mics doesn't mean they need to be held by a person, if you have control over shooting conditions. Mic stands and boom arms are your friend if you're a one-man show. this advice doesn't hold for walk-n-talks, of course.
- If you don't care if the lav is visible, using them are easy: mount them in the middle of the sternum, if possible. Otherwise, stick with a mic on a boom or search for "lav rigging" or "hiding lavs" online. A few videos are out there with solid advice. If you want to go deep, check RAMPS (rec.arts.movies.production.sound), where film sound pros discuss similar issues. Hiding lav mics requires a lot of practice and special lavs that won't sound muffled under clothing
- Lavs are harder to shield from wind, generally, as you can buy zeppelins/blimps as windscreens for std. mics.
- If you want to go wireless, do a video search for "Lectrosonics." They are the defacto standard (along with the even more pricey Zaxcom) in TV and film, and I'm not suggesting you buy a set. Instead, there's a series of Lectrosonics execs discussing the main considerations of wireless in a workshop. Good content, if dense! YouTube - Lectrosonics Wireless Seminar #1 (http://www.youtube.com/watch?v=YWcxS1rY--U) is the first one in the series.
- Interference comes in several flavors, from intermodulation (freq's interacting with each other), GSM (the dreaded cell phone chatter), and radio broadcasts (TV's are now digital). Working in enclosed spaces also can cause issues unless you use a "diversity" receiver - again, search for that online and you'll learn a ton. Cost in transmitters usually indicates how much interference they can resist - my Lectrosonics UCR401 receiver isn't the highest-highest end unit but I've never had a dropout, ever, period.
- Broadly, for those on a tight budget, the Sennheiser G2 and G3 units are pretty much the standard. Many folks love 'em.
- Don't use shotguns indoors, generally speaking, unless the room is REALLY acoustically dead. Go cardioid or hypercardioid. The interference tube design of shotgun mics makes for very tubby sound when soundwaves reflect off walls and hit the sides of the mic.

That's about the shortest answer I could offer... :)

Adam Gold
October 11th, 2009, 10:59 AM
In some situations you could consider going direct from a wired lav into the Zoom, which can easily be clipped to a belt or slid into a pocket. Okay, a big pocket.

Shawn Whiting
October 11th, 2009, 01:21 PM
Thanks for the great post Nathan. Ill have to read up on some things, but that gives me a good start.

only thing i didnt really understand was why a shotgun mic is bad to use indoors? how does the narrowness of its signal produce distortion inside?

also, in response to Adam, if i did go with wired lavs, wouldent they come with a pack that attaches to the person anyways? running a chord dragging along the floor to my camera while they walk and talk seems pretty risky, although i guess i could just work around that and have them stand in front of their students and speak, or slowly walk backwards through their labs.

- Shawn

Nathan Moody
October 11th, 2009, 06:10 PM
(While unorthodox. I think Adam's idea of planting an H4n on someone isn't a bad one at all, although that's recording double-system and will require syncing in post, but it's totally feasible and pretty low budget!)

Shawn, shotgun mics use a different kind of design known as an "interference tube." Their directionality is based on phase cancellation of off-axis sound that enters through the slots you'll see on the sides of the mic. When the sound coming into those slots are reflections of the sound you're recording on-axis (right in front), you'll get a weird sound that many refer to as "tubby" or "roomy." It's generally unpleasant to listen to. Other mic designs, even "traditional" supercardioids, don't generally have this problem. I've totally used shotgun mics inside, but only in specific, purposefully-dampened rooms for sound effects gathering. If I were in a hallway of any regular building, or a room I didn't have control over, the shottie would stay in the case for that shoot. :)

So, walk-n-talks with wired lavs are probably a non-starter for you. Wired lavs do NOT always have body packs on the talent/subject, although some need power modules that are clippable. In such cases, if you can scrounge up some help, having a friend boom might sound better with a lav. But remember that the boom op will be tethered to the camera (unless you instead get a wireless system to "camera hop" from the boom op to your camera).

But all these things are just guidelines. A boom operator with little skill and a cruddy mic will sound worse than a good lav (say, a Tram or Countryman) rigged well, and a great boom op with a nice mic will sound WORLDS better than a low-end lav...and a lot better than even most decent lavs.

If you're only going to have one person interviewed at a time, you'll just need a wireless receiver (Rx), a wireless transmitter (Tx), a lav specifically wired for the transmitter you're using, and an audio cable to go from the Tx to your camera.

The people in the industry who have the most wireless expertise, at this point, seem to be those involved in reality TV shows, where there are no rehearsals and pre-planned blocking, which makes booming practically impossible. Searching out comments from such pro's (many are on RAMPS, but Google appropriate terms as well) may help you to get the landscape better.

Believe me, I'm relatively new to wireless too, and I've not found a good single primer online yet. Hmm, maybe I should start one... ;-)

Best of luck!

Mark Boyer
October 12th, 2009, 01:18 PM
I do alot of trade show interviews and prefer to use a lav mic, it has a shorter range and is less likely to pick up room noise. I prefer a hard wired lav mic when shooting at the noisy trade show, a wired system is more relable and easier to quickly clip to the subject than trying to hook up a wireless system.

Adam Gold
October 12th, 2009, 08:10 PM
... if i did go with wired lavs, wouldent they come with a pack that attaches to the person anyways? running a chord dragging along the floor to my camera while they walk and talk seems pretty risky, although i guess i could just work around that and have them stand in front of their students and speak, or slowly walk backwards through their labs.Nathan answered this sooner and better than I could, but no, wired lavs don't have packs. They go right into your recording device, be it cam or Zoom. But since you said you had the Zoom, yes, I did mean to put the recorder on the subject, not on you or your cam, so no cables dragging.

And adding to the confusion over shotguns, hypers and supers is that many manufacturers use these terms interchangeably. The Senn ME66/67 are both referred to as Super-Cardioid shotguns, while a search at B&H shows a few Hypercardioid shotguns as well. So they're not mutually exclusive.

Mark Boyer
October 13th, 2009, 10:25 AM
Adam, some wired lavs have a box or pack that holds a battery for providing phantom power. My Trams have a transformer module about the size of a lifesavers roll.

Adam Gold
October 13th, 2009, 04:26 PM
Ah, good to know. Mine have the same barrel-shaped roll but I thought he meant something more like a transmitter box the size of a deck of cards.

Nathan Moody
October 13th, 2009, 05:42 PM
...and I wrote "chord" instead of "cord" and used "clippable" in terms of having a clip, not being clipped in terms of audio >0dB. Nice once, Nathan, you'll speak well someday. :-\