What it is and how it works
Normal compression is downward: it lowers what exceeds the threshold. Upward compression raises what lies below the threshold, leaving the peaks unchanged. The result is always reduced dynamics, but with a different character: the transients stay intact, while tails, details, reverbs, noise and breaths rise. It is the logic of parallel compression brought inside the processor.
Formula: below the threshold, with an upward ratio of 2:1, a signal 20 dB below the threshold is brought to 10 dB below. You always need a range (how much it can be raised at most, e.g. 6–12 dB) and often a lower threshold below which nothing is raised any more, otherwise the background noise would be brought up.
Tools
- OTT (Xfer, free): recreates the “Over The Top” preset of Ableton's Multiband Dynamics: 3 bands, simultaneous and very strong downward and upward compression. Parameters: Depth (overall amount, the main dosing control), Time (timings), In/Out gain, Upwd/Dnwd (upward/downward balance), gain per band. It has become a standard of EDM, future bass, dubstep and hyperpop sound design.
- Multiband Dynamics (Ableton), Pro-MB (FabFilter, supports compression and expansion above and below the threshold), Waves MV2 (two knobs: Low Level = upward, High Level = downward; simple and useful on vocals and bass), Ozone Dynamics and Ozone Low End Focus, Kilohearts Multipass.
- In FL Studio: Maximus has a drawable compression curve for each band and for the Master band: by drawing the below-threshold part higher than the diagonal you get upward compression. Transient Processor with the Release raised brings up the decay of the transients (similar in result). Parallel compression with mix (dry + heavily compressed) is the simplest upward.
Parameters one by one
- Threshold (upward): everything below it gets raised. Set it just below the level of the sound's body.
- Upward ratio: 1.5–3:1 natural; very high = “flat”, dense sound.
- Range / max gain: 3–6 dB discreet, 10–20 dB effect (OTT).
- Lower threshold / gate: avoids raising noise and silence (−50/−60 dB).
- Attack/Release: for upward, the attack decides how quickly the signal is “pushed up” when it falls below the threshold; long releases create a “sucking” effect. In OTT the Time control scales all the timings.
- Bands: in multiband (OTT) the upward works separately on lows, mids, highs: it makes every band full and “shimmering”.
- Depth / Mix: the most important dosing. OTT on synths: 20–50%; on the master: never high (5–15% or nothing).
When to use it and on what
- Synth sound design (supersaw, pluck, growl, chord stab): OTT 30–100% for a dense, bright, “in your face” sound. After OTT you often need EQ to remove 3–8 kHz harshness.
- Vocal: MV2 Low Level 20–40% to bring out consonants and details in whispered phrases without squashing the loud notes. Watch out for breaths and noises.
- Drums: bring up tails and room (alternative to parallel).
- Bass: constant sustain without touching the attack.
- Pads and ambient: light upward to bring out the textures.
- Mastering: light, multiband upward (Ozone, Pro-MB) for density in quiet passages; with caution.
Starting settings
| Source | Tool | Setting | Notes |
|---|---|---|---|
| Supersaw / EDM chord | OTT | Depth 40–70%, Time 30–50%, Upwd 100%, Dnwd 50–100% | EQ after: −2/−4 dB 3–6 kHz if harsh |
| Future bass pluck/lead | OTT | Depth 30–50% | Then reverb |
| Dubstep growl/bass | OTT (even several instances in series) | Depth 60–100% | Control the bass below 100 Hz (often HP after and a separate sub) |
| Vocal | MV2 or Pro-MB | Low Level +20–40% / upward 2:1, range 4–6 dB | De-esser after |
| Drums | Maximus / Pro-MB | Upward 2:1 on mids and highs, range 6 dB | Brings up ghost notes and room |
| Master | Ozone / Pro-MB | Range 1–2 dB, ratio 1.2–1.5:1 | Only if the mix asks for it |
By genre
- EDM, future bass, dubstep, hyperpop, phonk: OTT is almost a signature of the sound.
- Pop: upward on vocals and backing vocals for intimacy and detail.
- Hip hop: upward on sampled drums for “dirt” and tails.
- Acoustic/jazz: rare, only to bring out very weak passages.
Common mistakes
- OTT at 100% on everything: noise, harshness, a flat and fatiguing mix.
- Upward on tracks with background noise (home-recorded vocal): hiss and room become obvious.
- Forgetting that upward raises tails and reverbs: the mix's space changes.
- OTT on the master: loss of transients and harsh highs; if you want it, a very low mix.
How to hear it
- On a synth: listen with OTT at 0%, 30%, 100% at equal volume: the instrument becomes “closer” and brighter, and the decay stays high.
- On a vocal with MV2: listen to the word endings and breaths that come up; if the breaths bother you, lower it or add an expander before.
Starting settings
| Parameter | Value | Why |
|---|---|---|
| OTT depth on synths | 30–70% | Density without destroying the sound. |
| OTT depth on master | 0–15% | Otherwise you lose transients and dynamics. |
| Natural upward ratio | 1.5–3:1 | Details up without a pumped effect. |
| Range | 3–6 dB discreet, 10–20 dB effect | Limits how much the weak signal is raised. |
| Lower threshold | −50/−60 dB | Don't bring up noise and silence. |
| Waves MV2 vocal | Low Level 20–40% | Simple and musical upward. |
Frequencies to watch
| Range | What to do |
|---|---|
| Below 100 Hz | OTT raises the bass a lot: often HP after OTT on synths and a separate sub. |
| 3–8 kHz | Harshness appears after upward/OTT: bell EQ −2/−4 dB or de-esser. |
| 10–16 kHz | Upward on the highs brings up hiss and noise: check the noise floor. |
Example chain
| Step | Tool | Settings | Why |
|---|---|---|---|
| Source / synth | Sytrus, Harmor, Serum, Vital | Basic sound | OTT amplifies everything: start from a clean sound. |
| Upward/OTT | Xfer OTT / Maximus (curve) / Pro-MB / Waves MV2 | Depth 30–70% (synth), range 4–6 dB (vocal) | Density and detail. |
| Corrective EQ after | Fruity Parametric EQ 2 / Pro-Q | −2/−4 dB 3–6 kHz, HP if needed | Removes the introduced harshness. |
| Light limiter or clipper | Fruity Limiter / Fruity Soft Clipper | −0.5/−1 dB on the peaks | OTT can create peaks; the sound design stays controlled. |
| Space | Fruity Reeverb 2 / LuxeVerb / Valhalla | Send | Reverb after the density. |
How to check the result
- Track crest factor after OTT: synth 4–8 dB (very dense); if it drops below 4 dB the sound becomes flat and fatiguing.
- Noise floor in the silences: it must not rise above −60 dBFS after the upward.
- Spectrum: no new peak of more than 3 dB in the 3–8 kHz range compared with before the upward (otherwise corrective EQ).
- Equal loudness in the comparison with bypass (OTT raises the perceived volume a lot).