After this chapter you'll be able to set the level, timing, crossover and EQ on any output by hand. This is the manual counterpart to automatic room correction — useful for quick tweaks, or for adjusting a result the app produced.
The control surface
Select an output in the sidebar (Chapter 6 — Outputs & channel setup), then click Control. You'll see the control surface for that output:
- a header with the output name, a Link button, and Load / Save;
- three cards side by side — Gain, Delay, Crossover;
- a full-width EQ section below.
Every control is a number you type or step — there are no sliders, so you can dial in an exact value. The Gain and Delay cards also have − / + buttons: click one to step once, or hold it to glide the value in fine steps. A card that isn't doing anything (for example, Gain while the output is muted) dims to show it's inactive.
Changes take effect on the device immediately — there's no separate "apply" step.
Save writes this output's current settings to a .params file on your computer (named after the output), so you can keep a snapshot of a setup you like. Load opens a .params file and applies it to the output. If a file doesn't fit this output — say it holds more EQ bands than the output has, or a value out of range — nothing is changed and a message explains why.
Gain, Mute & Polarity
The Gain card holds three things: the level itself, plus Polarity and Mute buttons in its header.
Gain
- Type a level in dB, or use the − / + buttons — one click is 0.1 dB; hold a button to glide the level smoothly by ear.
- 0 dB is unity (no change); negative values make the output quieter.
- The available range is set by the device.
Use Gain to balance your speakers with the subwoofer — but the level-setting pass in room correction (Chapter 9 — Room correction & calibration) does this for you automatically.
Mute
Click the Mute button (speaker icon) to silence the output; it turns red and the header shows a MUTED pill. Click again (Unmute) to restore it.
Polarity
Click the Polarity button to flip the output's polarity (also called phase invert). It turns amber and reads Polarity: inverted; click again for Polarity: normal.
Inverting polarity flips the waveform. It can fix a subwoofer that's fighting the mains at the crossover (bass sounds thin when they're out of polarity). Room correction sets polarity for you when it aligns your speakers.
Delay
Delay holds an output back in time so all your speakers reach your ears together — essential when the sub and mains are different distances away.
- Type a delay value; the unit button cycles through units each time you click it: ms → m → samples → cm → in → ft.
- The − / + buttons step by one step of the unit currently shown (see the table below); hold one to glide the delay in fine steps.
- The maximum delay is about 8.5 ms (≈ 410 samples, ≈ 2.8 m).
- Reset sets the delay back to 0.
| Unit | Max | Step |
|---|---|---|
| ms (milliseconds) | 8.5 | 0.1 |
| m (metres) | 2.8 | 0.01 |
| samples | 410 | 1 |
| cm | 280 | 0.1 |
| in (inches) | 110 | 0.1 |
| ft (feet) | 9 | 0.01 |
The distance units (m, cm, in, ft) let you dial in delay as the extra distance to a speaker — e.g. if the sub is 1 m closer than the mains, add about 1 m of delay to the sub. Room correction (Chapter 9 — Room correction & calibration) measures and sets this for you.
Crossover
The crossover decides which frequencies each output plays. On the Really Mean Sub, the subwoofer output is low-passed (only bass) and the speaker outputs are high-passed (everything above the crossover) — the two meet at the crossover frequency.
- Type a crossover frequency in Hz. The range is 20–200 Hz; the Reset button returns it to 90 Hz.
- Choose an alignment from the dropdown: BW — Butterworth, or LR — Linkwitz-Riley.
The crossover slope is fixed (a steep 4th-order-class filter) and set for you — there's no slope control. Whether an output is high- or low-passed is a property of the output, not something you switch here.
Linkwitz-Riley (LR) is the usual choice for sub-to-speaker crossovers because the two sides sum flat through the crossover region. Set the same crossover frequency on the sub and the speakers so they hand over cleanly.
Parametric EQ
Parametric EQ (PEQ) lets you cut peaks and lift dips at specific frequencies. Each output has several bands; on the Really Mean Sub the speaker outputs have up to 8 bands and the sub output has 4.
There are two ways to edit — a graph at the top and control cards below — and they stay in sync.
The control cards
Each band card has four fields:
| Field | Unit | Range |
|---|---|---|
| Freq | Hz | 20 – 20,000 |
| Gain | dB | −18 – +18 |
| Q | — | 0.1 – 10 |
| Type | — | dropdown (below) |
Q is the width of the filter: low Q is wide and gentle, high Q is narrow and surgical.
Type offers seven filter shapes:
- 1Low Pass — passes lows, rolls off highs.
- 2High Pass — passes highs, rolls off lows.
- 3Peaking — a boost or cut around a centre frequency (the everyday EQ shape).
- 4Notch — a deep, narrow cut (to kill a resonance).
- 5Low Shelf — lifts or lowers everything below a frequency.
- 6High Shelf — lifts or lowers everything above a frequency.
- 7All Pass — changes phase without changing level (advanced).
Each band also has:
- a Bypass (power) button — switches the band off; it dims and turns grey;
- a Reset button — returns that band to its defaults (asks "Are you sure you want to reset this band?").
The graph — dragging nodes
The graph shows a numbered node per band and the combined response curve.
- Drag a node left/right to change its frequency, up/down to change its gain.
- Double-click a node (or Shift-click it) to reset it.
- Hover a node to see its Band number, Q, Freq and Gain.
- To change a band's Q, use the Q field on its control card.
The graph is hidden on very narrow windows — widen the window to bring it back, or use the number fields.
Bypass all & Flatten
Two buttons sit at the top-right of the graph:
- Bypass all — switches every band off in one click, keeping all your settings. The button becomes Enable all; click it to switch the bands back on, restoring exactly which bands were on before. Great for a quick with/without comparison of your EQ.
- Flatten — resets all bands to their defaults after a confirmation ("Are you sure you want to flatten the EQ?"). Use it to start clean.
Use Bypass all to listen without your EQ (settings kept); use Flatten to throw it away and start over.
Big EQ boosts eat headroom and can push the output into distortion. Prefer cutting peaks over boosting dips, and keep an eye on level. Deep room dips usually can't be EQ'd away at all — see the diagnostics in Chapter 15 — Diagnostics.
