Quick-reference limits and options. Values are for the Really Mean Sub at app version 0.1.3. Some ranges are set by the device and may differ on other hardware.
DSP block limits (per output)
| Block | Control | Range / options | Step | Default |
|---|---|---|---|---|
| Gain | Level (dB) | device-set (−90 … +24 dB) | 0.1 dB | 0 dB |
| Mute | On / off | — | — | unmuted |
| Polarity | Normal / inverted | — | — | normal |
| Delay | Time / distance | 0 – 8.5 ms (≈ 410 samples / 2.8 m) | see below | 0 |
| Crossover | Frequency | 20 – 200 Hz | 1 Hz | 90 Hz |
| Crossover | Alignment | Butterworth (BW), Linkwitz-Riley (LR) | — | — |
Delay units
| Unit | Max | Step |
|---|---|---|
| ms | 8.5 | 0.1 |
| m | 2.8 | 0.01 |
| samples | 410 | 1 |
| cm | 280 | 0.1 |
| in | 110 | 0.1 |
| ft | 9 | 0.01 |
Unit cycle order: ms → m → samples → cm → in → ft. Engine sample rate for conversions: 48,000 Hz. Speed of sound: 343 m/s.
The Gain and Delay cards also have − / + stepper buttons: a click moves one step, holding glides the value in steps (see Appendix C — Mouse & keyboard interactions).
Parametric EQ
| Item | Value |
|---|---|
| Bands per speaker output | up to 8 |
| Bands on the sub output | 4 |
| Frequency | 20 – 20,000 Hz |
| Gain | −18 … +18 dB |
| Q | 0.1 – 10 |
| Filter types | Low Pass · High Pass · Peaking · Notch · Low Shelf · High Shelf · All Pass |
Target curve
| Item | Value |
|---|---|
| Chart scale | ±12 dB |
| Control-point frequency | 20 – 20,000 Hz (step 1) |
| Control-point gain | −12 … +12 dB (step 0.5) |
| Minimum points | 2 |
| Presets | Tantrum Flat (recommended), Absolute Flat, N Curve, H Curve, D Curve, Custom |
Audio engine (Settings → Audio)
| Setting | Options | Default |
|---|---|---|
| Sample Rate | 44.1 / 48 / 88.2 / 96 / 176.4 / 192 kHz | matches your output device |
| Buffer Size | Auto (diagnostic) / 64 / 128 / 256 / 512 / 1024 / 2048 samples | 512 samples |
Auto (diagnostic) lets the audio device pick its own buffer size. It's there for troubleshooting only. Leave the fixed default unless we ask you to change it.
Measurement settings
| Setting | Options | Default |
|---|---|---|
| Averaging | Slow / Fast / Ultra-Fast / FIFO4 / FIFO8 / FIFO16 / FIFO32 | Slow |
| Smoothing | None, 1/48, 1/24, 1/12, 1/6, 1/3, 1/1 Oct | 1/6 Oct |
| Coherence (hide below) | Low / Medium / High / Very High | Low |
| Graph Scale | Full Scale / ±24dB Norm / Custom… | Full Scale |
| Clock Drift Correction | Enable / Disable | Disable |
Averaging speeds
Slow, Fast and Ultra-Fast are smooth “meter-style” averages settling in roughly 1.5 s / 0.5 s / 0.25 s. The FIFO modes average exactly the last 4, 8, 16 or 32 measurement frames, so the trace settles in a fixed, predictable time.
Custom… graph scale
Custom… lets you set your own ±dB window (1 – 60 dB) and visible frequency range (10 – 24,000 Hz).
Calibration / room-correction options (Settings → Calibration)
| Setting | Options | Default |
|---|---|---|
| Quick Positions | 1 / 3 / 5 / 7 | 1 |
| Full Positions | 3 / 5 / 7 / 9 | 3 |
| Clock Drift Correction | Enable / Disable | Disable |
| Gain Estimation | Target Level Match · Minimum Summed Error (Least Squares) · Matched Amplitude (RMS) | Target Level Match |
| Delay Estimation | Minimum Phase Error (Least Squares) · Cross Correlation Peak (GCC-PHAT) | Minimum Phase Error (Least Squares) |
| Time-Align Tops | Subwoofer only / All speakers | Subwoofer only |
| Phase Correction | Off / On | Off |
| Max Generations | Overkill (80) · Best (50) · Balanced (30) · Fastest (15) | Balanced (30) |
| Fitness Threshold | Best (10%) · Balanced (20%) · Fastest (30%) | Best (10%) |
| Confidence Weighting | 95% Strict · 70% Balanced · 50% Relaxed · 10% Permissive | 70% Balanced |
| Correction Filters | 1 – 48 filters per channel | 24 |
| Boost Trust | Off · Slight (80%) · Moderate (65%) · Maximum (50%) | Slight (80%) |
| Cut Trust | Slight (80%) · Moderate (65%) · Standard (50%) · Widest (30%) | Standard (50%) |
| Boost Restraint | Off · Gentle · Strong | Gentle |
These defaults are read from the app's saved configuration and may be refreshed by app updates. Your saved choices are kept across updates.
Correction Filters
Correction Filters caps how many EQ filters room correction may use per channel. The device's own slot count always applies too. On the Really Mean Sub that's 8 per speaker output (4 on the sub), so higher settings mean “use every slot the device offers”.
