Exterior Super cardiod, interior small diaphram?

B

Blutarski

Active member
I'm in the process of purchasing a shotgun mic. I understand a good super cardioid will be my main mic for exteriors with the windscreen. I was recently given information that a condenser type mic is preferable for interiors.
I've always wondered why I had echoes on some of my scenes. I was told that the use of a condenser type of mic would minimize this problem. My question is what is a good condenser mic for interiors? And for that matter a good super cardioid to minimize the ambient noises such as traffic wind etc.
 
There are quiet a few threads already up answering this question. Indoors you would want an Hypercardioid.


Nicole
 
Outdoors you normally need an interference tube (Gun) microphone and not a super-cardioid. You would use this in a Rycote.

Indoors, it depends on what you are doing. You could use a cardioid or super-cardioid here. A hyper-cardioid could also be used but the out-of-phase rear lobe can be rather large on a hyper, so be careful.
 
Blutarski said:
I'm in the process of purchasing a shotgun mic. I understand a good super cardioid will be my main mic for exteriors with the windscreen. I was recently given information that a condenser type mic is preferable for interiors.
I've always wondered why I had echoes on some of my scenes. I was told that the use of a condenser type of mic would minimize this problem. My question is what is a good condenser mic for interiors? And for that matter a good super cardioid to minimize the ambient noises such as traffic wind etc.
Click to expand...

You need to read up a bit on microphones in general so you'll understand what the terms mean. "Super-cardioid" describes the shape of the sensitivity pattern of the mic - how directional it is - that is, the shape of its "polar pattern." "Condenser" describes the technology that is used to convert the sound vibrations into electrical current, the other types being dynamic, ribbon, and ceramic. "Large-" and "small-diaphram" refers to the size of the vibrating disk that picks up the sound. Most modern super-cardioid mics ARE small-diaphram condensor mics.

The indoors/outdoors issue is one of how the mic goes about getting its directivity. A supercardioid shotgun such as the Rode NTG-3, technically a small-diaphram condensor mic, gets its directionality from a long, ported, interference tube that gives it its name. These are sensitive to reflections coming off of walls, ceilings, etc, and tend to sound 'echo'y' or 'ring'y' indoors and their directionality is dependent on the sound's frequency. A hypercardiod like tbe Schoeps CMC641, ALSO a small-diaphram condensor mic, does not use the interference tube but relys on a completely different physics to get its polar pattern. These mics do not have the same interaction of the desired sound with reflections that the 'gun does and so are better behaved indoors where there are a lot of reflections. The super cardioid and the hypercadioid patterns look almost exactly the same in the direction the main sound is coming from and a pretty much equally directional in the main direction - Schoeps even describes their mic as a super-cardioid pattern - but the shape of the pattern to sounds coming from the sides and rear directions are wildly different.

One of the primary causes of echos and that hollow sound like they were down in a well in your scenes is placing the mic too far away from the subject. For good clear pickup of dialog consisting of normal speech, a short shotgun such as the popular Rode NTG-2 or Sennheiser ME66, etc needs to be no farther away than about 22 inches from the speaker's mouth. Long shotguns can be a little farther out, 36 inches or so, hypercadioids need to be a little closer, around 18 inches, cardioids need to be a lot closer - 12 inches or so - and omnis even closer still, about 4 inches. Note that this doesn't depend much on the price or quality of the mic - whether you get a $200 Rode NTG-2, a $1200 Sennheiser MKH416, or a $2500 Schoeps CMIT for outdoors you'll need to keep it around 22 inches from the speaker for best results since these are all short interference tube shotguns
 
Last edited:
Remember that "shotgun" doesn't mean the traffic sound is completely eliminated.

It will be less... but never completely gone.

And as said by Steve 'go close enough"... just out of frame (like whoow, that was close) = out of frame. If it's out of frame, it's out of frame... That can be 0,00000001 inch
 
phudsontx said:
Microphone placement is like real estate. LOCATION, LOCATION, LOCATION.
Click to expand...

This is the distance rule:-

Imagine - An omni mic. 1-metre from the sound source.

The same sound will be picked up by:-
A cardioid at 1.7m
A super-cardioid at 1.9m
A hyper-cardioid at 2.0m
A short gun at 2.2m

So - your short gun mic. gets you just over double the distance of an omni.
 
You must log in or register to reply here.
Back
Top