DAD 310
Sound Design for Film

Editing and Cleaning Up Audio in REAPER

DAD 310 — Fall 2026

First work through LISTEN with the supplied files, including a finished export. Then open one of your own Assignment 3 recordings and work through the LISTEN checklist to finish and export it.

By the end of class, you should have one edited field-recorded take, a checked WAV export, and a short note explaining what you changed or left alone. This is practice for Assignment 4 , not an additional submission.

Have these ready

  • REAPER, headphones, and your Assignment 3 recordings.
  • A short detail recording to edit during the lab.
  • These demonstration files: clicky.wav , pops.wav , and low-freq-hum.wav .

Practice with the supplied files

L: Listen and mark the examples

  1. Use File > Save project as to create a project named Editing Practice. Enable Create subdirectory for project and Copy all media into project directory.
  2. Import clicky.wav, pops.wav, and low-freq-hum.wav onto separate tracks. Name each track after its file. Keep full-length copies on muted backup tracks, and label those tracks ORIGINAL.
  3. Solo each working track in turn and listen through it before editing. Identify the wanted sound and the click, pop, or low-frequency noise. Place the edit cursor at a problem and press M to add a marker. Double-click the marker to name it, such as click or pop.
  4. Keep only the example you are working on audible. Leave your Assignment 3 recordings closed until the next section, Edit your own recording.

Turn Ripple editing off and turn Snap off for these free-time SFX edits. You can use the toolbar buttons; hover over them to check their state. Removing an item should not unexpectedly move the rest of the session.

I: Repair clicks and pops

Solo the working clicky track. Select the item, place the cursor near the click, and zoom horizontally until you can see the brief disturbance. Increase the track height if the waveform is difficult to inspect.

  1. Listen across the suspected click to confirm its location. Place the cursor just before it and press S to split the selected item. Split again just after it.
  2. On the working copy, delete the tiny section containing the click. Listen to the gap. This shows why removing the waveform alone may leave an audible hole or a new boundary click.
  3. If the surrounding sound can tolerate a shorter duration, move the right item left so it slightly overlaps the left item. Enable Auto-crossfade on the toolbar and adjust the overlap until the join is unobtrusive.
  4. Alternatively, if duration or continuity must stay intact, undo any shortening and keep the original gap in place. Copy a clean piece of nearby background from the same recording onto a repair track, place it across the gap, and fade it in and out. Check that it does not repeat an obvious event or create a level bump at either end. Unsolo other tracks and solo both the working track and repair track to hear the complete edit together.
  5. Compare with the original. Undo the repair if it removes a wanted attack or draws more attention than the click.

Unsolo and mute clicky and any repair track, then solo the working pops track and locate the pop. If the pop overlaps wanted sound, do not cut away the entire event. Try a local level reduction by splitting around the problem and lowering that item’s volume in Item properties with F2, then check the new boundaries. For your own recordings, an alternate take may be better than repair. For speech-specific repair, see dialogue editing .

S: Compare processing on the hum example

Keep each example on its own track so one track’s processing does not affect the other practice files. Add one processor at a time through the track’s FX button. Use the effect’s checkbox in the FX chain to bypass it, and compare at similar listening loudness.

ReaEQ: reduce unwanted low frequencies

Unsolo and mute pops, then solo the working low-freq-hum track.

  1. Add ReaEQ. Select a band and change its type to High pass.
  2. Begin with the cutoff low, then raise it while listening. Stop when the unwanted low-frequency energy is reduced; back off if the wanted sound becomes thin.
  3. Bypass the band and compare. Describe what disappeared besides the noise.
  4. If the problem is a steady pitched hum, inspect the analyzer for a narrow peak. Try a narrow cut at that frequency instead of raising the high-pass cutoff through useful sound. Do not cut every visible peak.

There is no single cutoff setting for all your field recordings. Save the setting only if this recording sounds more useful with it.

ReaFIR: compare noise reduction on a fresh copy

Duplicate the original low-freq-hum item onto a new track with no FX. Unsolo and mute the ReaEQ version, then solo this new track. Look for a passage containing only the unwanted background. If the file has no suitable noise-only passage, skip this comparison; do not switch to your Assignment 3 recording yet.

  1. Add ReaFIR and set its mode to Subtract.
  2. Drag a time selection over the noise-only passage. Enable repeat playback and play that selection.
  3. Check Automatically build noise profile while the noise plays, then uncheck it before playing any wanted sound. Stop repeat playback and clear the time selection.
  4. Play the wanted event and its tail. Bypass ReaFIR and compare at similar loudness. Listen for missing texture or a metallic, watery decay.
  5. Use REAPER’s FX wet/dry control to blend some untreated signal back in if the fully processed result is too aggressive. Some noise will return too. Bypass the effect if the tradeoff is worse than the original.

Do not leave profiling enabled during the event: it would learn frequencies you wanted to keep. You do not need ReaFIR on every source for Assignment 4.

T: Check whether trimming is needed

Return to the working clicky track and any repair track it uses. Unsolo and mute the other examples; solo the working track and its repair track together. Keep the repairs you decided to retain. Use this same example through T, E, and N.

  1. Listen to the beginning and end. Is there a slate, excess silence, or unwanted material outside the sound you want to keep? clicky.wav is already trimmed; keep its existing boundaries if they still work after your repair.
  2. Only if needed, split with S or drag the item’s edges to remove unwanted material. Preserve the quiet beginning, full attack, and complete decay, with enough room for any needed fades. Leave the original track intact.
  3. If extending an edge makes the item repeat its contents, open Item properties with F2 and disable Loop source. Listen to the complete result and confirm that any boundary change helped.

Checking the boundaries satisfies this step. You do not need to shorten a recording that is already edited well.

E: Check every fade and join

  1. Listen to the existing boundaries first. Keep fades that already work. To add or adjust one, drag inward from an item’s upper-left or upper-right corner. Zoom in if the handle is hard to grab.
  2. If a boundary clicks, try a short fade and extend it only as far as needed. Right-click the fade to compare curve shapes.
  3. Check internal joins, including any repair patch. Where adjoining items can overlap, enable Auto-crossfade and adjust the overlap and curves by ear. Keep fixed-duration edits in place.
  4. Listen once close up, then again with several seconds of surrounding audio. Check for a softened attack, a missing tail, a dip, or a sudden texture change.

Keep the impact and decay intact. Do not add a long fade simply because it makes the waveform look tidy.

N: Normalize, name, and check the example

Export the repaired clicky example. Save this practice export separately from your Assignment 4 deliverables.

  1. Drag a time selection around the complete repaired example, including all its edited pieces and any repair patch. Include the full decay. Solo the working clicky track and its repair track, if used; keep originals and other examples muted. Play the selection to check what will be exported.
  2. Open File > Render. Set Source: Master mix and Bounds: Time selection. This combines the edited pieces and any repair track into one file and includes their processing.
  3. Set File name to ClickRepair_Practice and the destination to a Practice-Exports folder inside this practice project. Choose WAV, 24-bit, and match the source file’s sample rate and channel count.
  4. Open the render window’s Normalize/Limit/Fade settings and use peak normalization with a target of -0.5 dBFS for this practice export. Do not substitute a LUFS target or add a limiter to meet the peak target.
  5. Check the output filename and render statistics, then import the exported WAV onto a fresh track with no FX. Solo that track, listen from beginning to end, and verify its peak, channel count, start, and decay. Do not play it through the cleanup chain again.

Edit your own recording

Save and close the practice project. Open a separate editing project for one short detail from your Assignment 3 recordings, then repeat LISTEN:

  1. Listen: Save the new project with Copy all media into project directory enabled. Keep the full recording on a muted ORIGINAL track and a working copy on an EDIT track. Listen through it and mark what to preserve or repair.
  2. Identify: Locate any clicks, pops, or other unwanted sounds. Use the repair methods above only where they fit the problem.
  3. Signal process: Try EQ or noise reduction only if needed. Compare with the original at similar listening loudness; a clean take can stay unprocessed.
  4. Trim: Check the start and end. Remove a slate or unwanted material only if present, preserving the full attack and decay. Keep existing boundaries when they already work.
  5. Examine: Check fades and joins by ear, including several seconds around each edit.
  6. Normalize and name: Use the UCS naming and export workflow and Assignment 4’s WAV format and sample rate. Export this detail as mono to FINAL-SFX, with a final peak of -0.5 dBFS. Reimport it onto a clean track and listen to the entire file. If your finished sound spans several items or tracks, use the complete time-selection export above with the UCS filename, or a named-region export from the UCS guide, so it remains one WAV.

Play the result for a partner. Switch between the original and edit at similar listening loudness, and ask them to listen without watching the screen.

Before you leave, have:

  • A saved session containing the original and the working edit.
  • One checked export with a complete attack and decay and clean boundaries.
  • A sentence identifying the source, the problem, and the result, or explaining why no processing was needed. This can become one of Assignment 4’s five notes.

For an optional comparison, audition a similar sound in Soundly or SoundQ. Compare its boundaries and usable tail with yours. This is a reference check, not another export requirement.

When you edit an ambience bed

Use the same workflow on your Assignment 3 ambience recordings when preparing Assignment 4’s two beds.

For an Assignment 4 ambience bed, make a time selection exactly 1:00 long using the selection start/end or length fields. Choose a usable stretch and trim the working items to those boundaries. Keep the stereo bed on its own track. Internal edits must preserve the one-minute duration; keep ripple editing off. Finish assembling the bed before preparing its export.

Listen to both stereo channels across every join. A clean-looking cut in one waveform does not prove the other channel is clean. Export each bed as stereo with a peak target between -18 and -6 dBFS, then check its duration and continuity in the rendered WAV.

REAPER references

  • REAPER User Guide : item editing, fades, render settings, and the ReaEffects guide.
  • ReaPlugs reference : ReaEQ filters and ReaFIR’s Subtract mode. These effects are included in REAPER.