Acoustic Bounce (page 2)

Don't Kill the Reverb

You can go overboard with acoustic treatment, killing reverb in a room almost entirely. If you want to capture the feel of real-world locations, this type of acoustically sterile environment is not the way to go.

studios of the '60s and '70s used this type of acoustically "dead" room, created by piling shag carpet and egg crates on the walls. Today's audio engineers recognize the added realism of natural ambience when recording sounds or music.

Still, sometimes an acoustically dead room is exactly what the videomaker needs. When doing voiceovers, any reverb with the voice can prove distracting. If you're trying to simulate someone whispering in the viewer's ear, less ambience makes for a more convincing effect.

Pros often use small, foam-lined rooms called iso (isolation) or voiceover booths for recording narration.

Free-standing iso booths turn any room into a controlled acoustic environment. They're available in a wide range of sizes, and break down quickly for transport. WhisperRoom of Morristown, Tennessee markets portable iso booths on wheels, complete with ventilation systems.

If you plan to add ambient effects during editing or dubbing, you can get away with recording dialogue or sound effects in a reverb-free room. This will give you added control over the final sound, but requires more equipment and time in the end. When you add reverb during post-production, be careful to choose an effect that matches the visuals. If a group of people are chatting in a small room, adding coliseum-sized reverb will ruin the illusion.

For good examples of ambience not matching the accompanying images, catch a couple re-runs of The Brady Bunch. Listen closely to scenes supposedly shot in the Brady backyard. If you concentrate, you'll hear that they have a definite "indoor" ambience to them. You can't miss the telltale acoustic signature mingling faintly with the voices.

This is because the sound from the actors bounced around an indoor sound stage, one that needed more acoustic treatment. The resulting ambience isn't really reverb; it's more like a handful of very short echoes. The effect is subtle, but realism does suffer.

If these scenes truly had been shot outside, sound would have radiated away unhindered. A clever set may fool your eyes, but your ears know the difference between indoor and outdoor acou…