Filming in small rooms. Mic options to reduce echo?

A

analog_addict

Well-known member
Hello all,

Like a lot of people I have a Rode NTG-2. I am struggling with echo in small rooms and yeah, it's true you can't do much in post.

I'm shooting my next short film soon which I'm putting money into so I want the sound to be excellent. Nearly all the dialogue happens outside which is fine but there is a very lengthy scene in a garage which takes up a large chunk of the film.

It's a narrow garage with very little room for anything so sound blankets etc are completely out of the question. The walls are already covered in shelving, paint tins etc so it's not possible.

Is there a better type of microphone I could be using instead of a shotgun for this scene? I have a bit of budget to rent equipment so getting another mic shouldn't be a problem.

I was thinking lav mics could reduce echo but due to the small room size most shots are going to be quite close to the talent so it would be very difficult to hide the mics correctly.

Thanks for any tips!
 
Lavs could help because they are so close to the talent, and can be hidden under clothing...but in a small live space, a lav (which is usually omnidirectional) can pick up a lot of reflected sound. Best bet is a hypercardiod mic on a boom, which is so directional it will tend to pick up the voice and reject the reflections. In any shot where the floor is not seen, throw down a room sized rug to cut down on the echo.
 
With all that stuff on the walls you probably won't have much of an echo problem. Shoot a test and see.
The key as always is getting close.

BTW "excellent" sound only starts with good production recordings.
 
Why can't you put sound blankets directly in front of the shelves? Take stuff off of the top shelf and then use it to weight down the sound blankets so they hang in front of the shelves.

Of course, you can always look for another roomier location.

Hiding lavs is not all that difficult.

 
Generally speaking, hypercardioid mics are used a majority of the time for indoor scenes. The pickup pattern is different than a shotgun and without getting too technical, it reduces the echoing you're getting (google it up to learn more). On the lower-end of things, the AKG 300b w/CK93 HC head, Audix SCX1-HC, and Oktava MK-012 (although these have a bit of handling noise- choose the other two first) can both be had for under $500 (Audio Technica AT4053b for $600), cheaper used or rented. On the higher-end of things, the Schoeps CMC641, Sennheiser MKH50, and Neumann KM series HC's are all over a grand but what are used often. Any of these microphones will yield significantly better results indoors than your NTG-2, especially in tight rooms with lots of reflection. Remember if you're buying or renting to get a good shockmount for it. The Rycote Invision systems work great and are pretty affordable, and don't forget a good softie for it.
 
mainstreetprod said:
...a hypercardiod mic on a boom... is so directional it will tend to pick up the voice and reject the reflections.
Click to expand...

This is very inaccurate.

The hypercardioid pattern is not "more directional" than a shotgun. And it's not a lack of "directionality" that causes a shotgun to behave poorly in some indoor situations.

The interference tube that gives the shotgun it's typical (very narrow) response pattern uses as principle of physics that is thwarted in reflective environments. In short, the tube takes sound coming from the sides and knocks it out of phase with itself, effectively canceling the sound out. But in reflective environments, the reflections are already slightly out of phase by the time they hit the mic, rendering the 180° phase cancellation improbable/impossible, and serving only to enhance the reflections and muddy the sound.

The hypercardioid may be the mic of choice in a more reflective interior not because it rejects reflections, but because it records them in a more natural-sounding proportion to the direct sound, assuming proper mic placement. The pattern is tighter in front than a regular cardioid, and it has a small lobe of response to the rear. Put it outdoors, and it cannot reject from the sides like a shotgun can.

A shotgun can work for interiors, however, in many situations. It just has to be used correctly. I have hit places where my NTG-3 just wouldn't behave and the hyper was a better choice, but I have shot many interviews in residential and office spaces that would seem less than ideal and have gotten great results from the shotgun. Personally, I tend to favor the hyper in most interiors for narrative work because the smaller mic gives me more liberty of movement in a place with low physical headroom.
 
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