Chapter 15 — Quiz

Twenty-nine questions to check that the discipline of location sound has stuck: double-system and sync, booming, monitoring, levels and headroom, taming the room, and room tone. Answer from memory, then check the key at the end — it includes a one-line explanation for each and a "topics to review" map so you know exactly where to go back.

Notation reminder: audio levels are in dBFS (with 0 dBFS the hard ceiling); headroom is a gap in dB.

Part 1 — Multiple choice

1. Double-system sound means: - (a) recording with two microphones for safety - (b) recording picture on the camera and audio on a separate device - (c) recording in stereo - (d) recording the same take twice

2. The main reason you still record the camera's own (thin-sounding) mic on a double-system shoot is: - (a) it sounds better than you'd expect - (b) to have a scratch/reference track for sync and as a backup - (c) it's required by the camera - (d) to record room tone

3. A hand clap works as a sync marker because it creates: - (a) a loud average level - (b) a sharp transient spike that lands at the same instant in both files - (c) a timecode stamp - (d) a change in white balance

4. The default, best boom position is: - (a) from below, pointing up at the chest - (b) overhead, aimed down at the mouth - (c) beside the subject at ear height - (d) clipped to the subject's collar

5. You'd choose to boom from below instead of overhead when: - (a) the subject is speaking quietly - (b) a wide shot, a low ceiling, or a boom shadow makes overhead impossible - (c) you want the most natural sound - (d) you're recording room tone

6. Monitoring on a shoot means: - (a) watching the level meters carefully - (b) checking the camera's screen - (c) listening to the recorder's output on closed-back headphones while you record - (d) recording a test and reviewing it at home

7. A level meter is blind to which of these? - (a) how loud the signal is - (b) whether the signal is clipping the ceiling - (c) hum, reverb, and clothing rustle - (d) the peak value

8. The recommended average level for location dialogue is about: - (a) -3 dBFS - (b) 0 dBFS - (c) -12 dBFS - (d) -40 dBFS

9. Headroom is: - (a) the space above the subject's head in frame - (b) the gap in dB between your peaks and 0 dBFS - (c) the quietest sound a system can record - (d) the reverb tail of a room

10. You should turn off automatic gain control (AGC) for dialogue because: - (a) it makes the signal too quiet - (b) it pumps the noise floor up in the pauses between sentences - (c) it disables the meters - (d) it prevents clipping

11. The single strongest weapon against room reverb is: - (a) turning up the gain - (b) a high-pass filter - (c) getting the mic closer, plus absorption - (d) a furry windscreen

12. Wind protection for real outdoor wind means: - (a) a foam windscreen - (b) a furry "dead cat" cover - (c) a high-pass filter alone - (d) turning the gain down

13. Room tone is: - (a) the musical key of a scene - (b) the unique ambient sound of a space with no one talking - (c) the tone control on a mixer - (d) true silence

14. You should record room tone: - (a) once, at the start of the shoot day - (b) only in noisy locations - (c) at every location and setup, with the same mic, position, and levels - (d) only if the editor asks for it

15. A high-pass (low-cut) filter helps on location by: - (a) boosting the voice - (b) rolling off low-frequency rumble and handling noise below ~80 Hz - (c) removing reverb - (d) adding headroom

Part 2 — True / False (justify your answer in one line)

16. Clipped audio can be repaired in post by lowering the level.

17. On a controlled seated interview, "set and forget" the level is usually better than constantly riding the gain.

18. A room tone recorded in the kitchen can be safely used under dialogue shot in the living room.

19. In double-system recording, if you have a good external recorder you should turn the camera's microphone off.

20. Reverb is generally harder to fix in post than a steady background hum.

Part 3 — Short answer

21. In one sentence each, explain the on-set fix for two of these faults: room echo, clothing rustle on a lav, wind roar outdoors.

22. Describe the three-second ritual you run before every double-system take, and say what each part gives the editor.

23. Give the target average level, the peak ceiling, and the amount of headroom for location dialogue, and explain in one sentence why the safe direction in digital audio is "too quiet," not "too loud."

24. List three of the nine faults you monitor for on headphones that a level meter would not catch.

Part 4 — What's wrong here? (perception)

25. A crew shoots a beautiful window-lit interview double-system. In the edit they discover: the good recorder's files are gorgeous but drift out of sync with the picture and can't be auto-aligned; every third take has a faint refrigerator hum; there is a hard silence between every dialogue take; and one laugh crackles. For each of the four problems, name the specific on-set discipline from this chapter that was skipped and would have prevented it.

Part 5 — Applying it

26. A safety (backup) track is most valuable when: - (a) you have plenty of time to re-record - (b) you're capturing an unrepeatable moment (an event, a speech) where a surprise peak might clip the main track - (c) the room is very quiet - (d) you're using a single-system setup

27. Short answer. You're booming a two-person conversation with one mic. Describe what you do with the boom as the two people trade lines, and why parking it in the middle is wrong.

28. True / False (justify). The high-pass (low-cut) filter should be left on for every recording.

29. What's wrong here? A shooter records an interview in a tiled kitchen. They set the level so speech peaks at -3 dBFS "to keep it strong," watch the meters instead of wearing headphones, leave the dishwasher running because "it's quiet," and pack up as soon as the subject finishes the last answer. Name four separate mistakes and the fix for each.

Answer Key

Show answers, explanations, and the review map **1. (b)** — Double-system = picture on the camera, audio on a separate device, married in the edit. *(§15.1)* **2. (b)** — The camera mic is the **scratch track**: it carries the sync clap and is a backup. You never use it in the final mix. *(§15.1)* **3. (b)** — A clap is a sharp **transient** whose spike appears at the same instant in both recordings, so you stack the spikes to sync. *(§15.1)* **4. (b)** — Overhead aimed down at the mouth is the default: on-axis voice, and the mic's dead side rejects floor/foot noise. *(§15.2)* **5. (b)** — Go low only when forced: a wide shot, a low ceiling, or a hard key that would throw a boom shadow. *(§15.2)* **6. (c)** — Monitoring = actively listening to the recorder's output on closed-back headphones *while recording*. *(§15.3)* **7. (c)** — A meter shows loudness, not quality: hum, reverb, and rustle can all hide inside a "healthy" level. *(§15.3)* **8. (c)** — Aim for dialogue averaging around `-12 dBFS`. *(§15.4)* **9. (b)** — Headroom is the dB gap between your loudest peaks and the `0 dBFS` ceiling — your safety margin. *(§15.4)* **10. (b)** — AGC cranks gain up in pauses, dragging noise/hiss up into an audible "pumping." Set gain manually. *(§15.4)* **11. (c)** — Proximity plus absorption beats reverb; getting closer raises the direct voice over the room's reflected sound. *(§15.5)* **12. (b)** — A furry cover (windjammer/"dead cat") is for real outdoor wind; foam is for indoor air and breath. *(§15.5)* **13. (b)** — Room tone is the specific ambient signature of a space with no one talking — not true silence. *(§15.6)* **14. (c)** — Every location and setup gets its own room tone, recorded with matching mic/position/levels. *(§15.6)* **15. (b)** — The high-pass/low-cut rolls off rumble and handling noise below ~`80 Hz`, where the voice mostly isn't. *(§15.5)* **16. False** — Lowering the level just makes the distortion quieter; clipping chops the top off the wave permanently and cannot be rebuilt. *(§15.4)* **17. True** — On a controlled shoot consistency is the goal; fiddling introduces level jumps. Ride the fader only when the situation is unpredictable (events, moving subjects). *(§15.4)* **18. False** — Each space has a different acoustic fingerprint; a mismatched tone is audible under the dialogue. Every setup needs its own. *(§15.6)* **19. False** — Keep the camera mic on as a scratch/reference track for sync and backup; turning it off leaves nothing to align against. *(§15.1)* **20. True** — Reverb is the voice itself, delayed and smeared, so it resists clean removal; a *steady* hum is consistent and can often be reduced by noise reduction (Chapter 33). *(§15.5, §15.6)* **21.** Any two: **room echo** → get the mic closer and add soft absorption (blankets/curtains/rugs); **lav rustle** → re-mount the capsule away from moving/synthetic fabric, with a cable loop for strain relief; **wind roar** → a furry cover plus your body between the wind and the mic. *(§15.5)* **22.** With camera and recorder both rolling, hold a hand (or clapper) *in frame*, say the take number aloud, and clap once sharply. The clap gives the editor a sync spike in both files; the spoken take number labels the audio; keeping the camera mic rolling gives a scratch/backup. *(§15.1)* **23.** Average `~-12 dBFS`, peaks under `~-6 dBFS`, `6–12 dB` of headroom. Safe direction is "too quiet" because a clean quiet signal is trivially raised in post, while a clipped one is destroyed forever — `0 dBFS` is a hard wall. *(§15.4)* **24.** Any three of: clipping/distortion, hum/buzz, HVAC/fridge, wind/rumble, clothing rustle, plosives, echo/room, off-mic drift, intermittent hits, wireless dropouts. *(§15.3)* **25.** (1) Out-of-sync, un-alignable files → no **scratch track and/or no clap** was recorded (§15.1). (2) Refrigerator hum → the **motor wasn't killed** and no one was **monitoring** on headphones (§15.3, §15.5). (3) Hard silence between takes → **room tone was never recorded** (§15.6). (4) Crackling laugh → levels were too **hot with no headroom** (and no safety track); should have set to `-12`/tested the loudest line (§15.4). *(synthesis)* **26. (b)** — A safety track (recording the same mic ~12 dB lower) exists to survive a surprise clip on an unrepeatable moment; if the main track blows out, the editor swaps to the clean safety. *(§15.4)* **27.** You **favor the talker** — swing/rotate the mic so its on-axis line lands on whoever is currently speaking, and anticipate the next line by leading the swing a beat early. Parking it dead-center leaves *both* voices off-axis and distant, so both sound weaker and roomier than they should. *(§15.2)* **28. False** — The high-pass rolls off lows below ~`80 Hz` to kill rumble/handling noise, but it can thin a deep voice; turn it off when you hear it hollowing out the low end. It's a scalpel, not a default. *(§15.5)* **29.** Four mistakes: (1) **peaks at `-3 dBFS`** → almost no headroom, will clip on any loud word → aim `-12` average, peaks under `-6`. (2) **watching meters, no headphones** → misses hum/echo/rustle → monitor on closed-back headphones. (3) **dishwasher running** → steady motor noise under everything → kill the motor before rolling. (4) **packed up with no room tone** → the edit has no bed to fill gaps → record 30–60 s before leaving. Bonus: the **tiled kitchen rings** → get closer and deaden it. *(synthesis)* --- ### Topics to review by question | If you missed… | Review | |---|---| | 1, 2, 3, 19, 22 | §15.1 Double-system sound and syncing | | 4, 5, 27 | §15.2 Booming technique | | 6, 7, 24 | §15.3 Monitoring | | 8, 9, 10, 16, 17, 23, 26 | §15.4 Levels and headroom | | 11, 12, 15, 20, 21, 28 | §15.5 Taming the room, wind, and noise | | 13, 14, 18 | §15.6 Room tone | | 25, 29 | whole-chapter synthesis |