BeePressor Manual

BeePressor is a graph-led multiband dynamics processor. The graph is not only a meter. It is the primary control surface for band topology, crossover placement, threshold, ratio or range, gain, filter character, sidechain focus, and selected band identity. The lower drawer then exposes the controls that require compact text, timing detail, transfer editing, or path-specific advanced operation.

Graph range

Frequency is read on a log axis from 20 Hz to 20 kHz. Threshold and gain overlays are level references in dB.

Signal convention

Positive makeup gain raises the processed band after gain calculation. Gain reduction is displayed as attenuation relative to the unprocessed band.

Path convention

Primary path means the stereo path in Stereo mode or the Mid path in M/S mode. Side path means the independent Side path in M/S mode.

Safety convention

Set processing first, match output second, and use Delta only as an inspection mode before returning to normal monitoring.

Read the page in layers. First identify the signal path and the control ownership. Then read the topology rules: what creates an audible band, what changes the gain law, what changes compressor character, and what changes filter character. Procedures are useful only after those ownership boundaries are clear; the tables at the end are for lookup after the terms have a working meaning.

Feature Inventory

BeePressor combines multiband topology editing, per-band dynamics selection, detector routing, character filtering, and technical monitoring in one control model. The complete public feature inventory is:

• One to twelve active compressor bands with graph crossovers, crossover slope chips, split/remove controls, band focus, and per-band inspector state.
• Per-band Stereo or M/S mode with independent Mid and Side path parameters.
• Per-band bypass, solo, threshold, ratio or range, makeup, attack, wait, release, attack shape, release shape, knee where applicable, and selected path state.
• Full Dynamics topology list: Classic compressor, Lookahead limiter-compressor, Upward/downward density, RMS leveler into peak limiter, Spectral compressor, Causal state-space compressor, Noise gate, Downward expander, Wavelet recruitment compressor, Modulation-domain compressor, SNR-aware compressor, Sliding-band compressor, and Channel-free compressor.
• Classic Comp character list: VCA, FET, OPTO, VARI-MU, Tape, Custom, and Soft Clip.
• Per-band filter character with Clean, Moog Ladder, SEM, MS-20, Roland OTA, CEM3320, Steiner-Parker, Twin Peak, CMOS, State Variable, Baxandall, Passive LC, Sallen-Key, and Diode Ladder options.
• Filter resonance handles and lower/upper filter-corner shifts on compatible filter characters.
• Detector source routing from Self, another active internal band, or External host sidechain.
• External sidechain split through the same active crossover layout, so a band listens to the corresponding external frequency region.
• Engine controls for detector mode, RMS window, stereo link, external blend, detector listen, ADAA, and focused-path oversampling or lookahead where supported.
• Five-band detector-only sidechain EQ with high-pass, three bell bands, and low-pass roles.
• Envelope editor for attack, wait, release, attack/release shapes, two-stage release behavior, auto-release timing, and envelope scale.
• Custom transfer editor for point and handle shaping when the selected band uses Custom compression.
• Auto/Apply workflow that captures pre-DSP input spectrum, proposes band layout and settings, and commits only when Apply is used.
• FFT analyzer, Hi-Res 121-band 1/12-octave visualizer, analyzer ballistics, brightness, smoothing, hold, peak readouts, centroid, tilt, and band-energy telemetry.
• Input, output, and gain-reduction meter rail with meter history and right-click meter modes.
• Delta monitor for hearing input minus processed output.
• Factory/user presets, preset link copy/paste, host automation compatibility, state restoration, and host sidechain behavior.

The feature inventory is grounded in the local BeePressor project Manual.md and public BeeAudioModules parameter contracts for names, ranges, visible labels, and supported or omitted controls. External references below are used only for general DSP terminology and documentation practice; they do not override product behavior.

The inventory is broad because BeePressor joins three tasks that are often separated: dividing the spectrum into useful regions, selecting the gain law for each region, and deciding what the detector should hear. A casual reading can stop at those three tasks. A deeper reading should follow the ownership chain from band layout to detector source, then from detector source to Dynamics, then from Dynamics to Comp, Filter, timing, and monitoring.

Gain staging rule

Set threshold, ratio/range, timing, detector source, and topology before using makeup. Makeup can make a band sound subjectively better while hiding excessive gain movement. Compare with the output meter and briefly inspect Delta before committing.

Scope and Terminology

BeePressor has four topology layers. The multiband topology layer defines band count, crossover frequency, crossover slope, split/remove state, and the legal frequency region for each active band. The Dynamics layer defines the gain-law family inside the focused band. The Classic Comp layer defines compressor model behavior only when Dynamics is Classic compressor. The Filter layer defines band-edge character, resonance, and shifted filter corners.

The four topology layers are a guardrail against false diagnosis. If a band clamps too much high-mid energy, a crossover move changes the audio region, a detector-key change changes what is measured, a Dynamics change changes the law that converts measurement to movement, a Comp change changes the Classic compressor character, and a Filter change changes the edge tone. Those edits may sound related, but they answer different questions.

These layers are independent in normal operation. A band can keep the same crossover placement while changing Dynamics. It can keep the same Dynamics while changing VCA to FET or OPTO. It can keep the same compression behavior while changing a Clean band edge into a resonant SEM or diode ladder edge. This separation is important because the visible graph can show topology, detector, gain law, and character without pretending they are the same parameter.

The word band means an audible crossover region in BeePressor. This differs from BeeDyn, where Band means an EQ node inside a full-band cascade. In BeePressor, reducing band count changes the active split/recombine topology. Inactive band settings can remain stored for compatibility, but they are not part of the audible topology until the band count expands again.

Notation

Threshold is a detector-level reference in dB. Ratio describes ordinary compression steepness where supported. Range describes the maximum downward movement for gate and expander topologies. Wait is a pre-attack delay for gain movement away from neutral; it is not a detector freeze. ADAA means antiderivative anti-aliasing for compatible nonlinear or static transfer stages.

System Description

BeePressor applies input trim, splits the program into active bands, processes each band, recombines the bands, applies mix and output trim, and publishes telemetry for graph, analyzer, meters, and preset state. Each active band owns its detector source, selected path, dynamics topology, compression model where applicable, filter character, timing, transfer behavior, and meter history.

Signal path and detector path should be read separately. The signal path answers what audio is processed. The detector path answers what level, spectrum, channel, or sidechain signal causes movement. Self keying makes those paths match. Internal and External keying deliberately make them differ.

Input trim Crossover split Per-band dynamics and filter character Band recombine Mix and output trim

Detector routing is independent from the audio region being processed. Self keying reads the focused band. Internal keying lets one band drive another band's gain movement. External keying uses the host sidechain input and splits that sidechain through the same crossover layout so the focused band listens to the corresponding external frequency range.

SelfFocused band audio -> detector -> focused band gain

Internal keySelected band audio -> detector -> focused band gain

ExternalHost sidechain -> crossover split -> detector -> focused band gain

M/S mode converts the selected band into Mid and Side paths, applies path-specific settings, then converts back to stereo before recombination. The primary path uses the Mid parameter set in M/S mode. The Side path has its own threshold, ratio/range, makeup, timing, model, filter, and advanced path state.

Focused band M/S encode Mid path parameters Side path parameters M/S decode

The live analyzer is an input visualizer. It is not a promise that the drawn curve is post-compression output. The meter rail and gain-reduction history show processing state. Delta auditions the difference between input and processed output. Use all three views together when the question is whether a setting is changing tone, envelope, or only level.

Detector measurement is separate from audio ownership. A high band can compress because its own high-band detector crossed threshold, because another internal band crossed threshold, or because the corresponding External sidechain split crossed threshold. This is why a correct diagnosis starts with Key and detector listen before attack, release, or makeup.

Control Surface

The main graph carries the information that needs continuous spatial editing: spectrum, active band regions, crossovers, split/remove controls, slope chips, focused threshold overlay, focused makeup lane, resonance handles, shifted filter-corner guides, Auto capture spectrum, and meter history. It is a frequency editor and a dynamics reference at the same time.

The focused drawer follows the selected band and selected path. It contains Mode, path focus, Key, Dynamics, Comp, Filter, On/Off, Solo, threshold, ratio or range, makeup, envelope timing, custom transfer where applicable, and advanced operation where the current band and model support those controls.

The Engine tab belongs to detector and quality behavior. It contains detector mode, RMS window, stereo link, external blend, detector listen, ADAA, and supported oversampling or lookahead controls. Detector mode changes the measurement law. RMS window changes averaging only when RMS-style detection is active. Stereo link changes how strongly stereo channels share detector movement. External blend changes how the external key combines with local detection when external routing is present.

The SC EQ tab is detector-only sidechain EQ. Its five fixed roles are high-pass, three bells, and low-pass. It changes the signal used for detection and detector listen. It does not directly equalize band output. The same band may sound brighter or darker only because the detector starts moving differently.

The Timing tab contains curve law, wait, auto-release, envelope scale, and transfer shape/depth where the selected topology supports those controls. Timing controls affect gain movement. They do not move crossovers, filter corners, or analyzer ballistics.

The visualizer drawer controls display and capture behavior. FFT controls include Bin and Ov. Hi-Res uses a 121-band 1/12-octave filter-bank estimate. Hold freezes analyzer display and prevents Auto ingestion. Analyzer controls do not directly change audio processing.

Table 1 is a control-ownership map. Use it when a visible result is ambiguous: a graph gesture may change topology, a drawer control may change only the focused path, and a visualizer control may change display without changing audio.

Table 1. Control surface ownership.

Area	Owns	Does not own	Operational note
Main graph	Band focus, crossovers, split/remove, threshold, gain, resonance, corner shifts, visible history.	Detailed timing curves and sidechain EQ values.	Use it to establish topology and first-order gain law.
Focused drawer	Focused band/path controls, timing, model, filter, custom transfer.	Global preset storage and analyzer mode.	It retargets when band or M/S path changes.
Engine	Detector behavior, detector listen, quality controls, ADAA.	Direct EQ tone.	Use after threshold/timing are close.
SC EQ	Detector-only high-pass, three bells, low-pass.	Audio tone path.	Use detector listen to verify the key signal.
Visualizer	Display mode, hold, FFT size, overlap, display ballistics, brightness.	Compression attack/release.	Hi-Res and FFT are analysis views, not DSP modes.

Interaction Rules

Click a band to focus it. Drag a crossover badge left or right to change crossover frequency. Drag a slope chip up or down to change crossover slope. Split controls add a band inside the selected range. Remove controls collapse the active topology while preserving compatible inactive settings.

Shift-drag a crossover line to edit the focused band's adjacent filter-corner shift without moving the actual crossover. Shift-drag an existing dashed shifted line to edit that shifted corner directly. Command-click on macOS, or Control-click on Windows/Linux, a slope chip to reset the focused shift. Filter-corner shift is measured in semitones and spans -24 to +24.

Drag resonance handles up or down when the selected filter character supports resonance. In one-band mode there are no crossover edges, so resonant filter characters expose a focus anchor instead. Drag that anchor left/right to tune focus frequency and up/down to change resonance amount. The one-band focus uses the same stored corner-shift parameters for compatibility; when the topology expands, those values return to ordinary corner-shift meaning.

Right-click Auto to choose maximum Auto band count from 1 to 12. Click Auto to start or stop pre-DSP spectrum capture. Click Apply to commit suggestions. Auto Max Bands is a ceiling, not a requested count.

Shift-click the BeePressor title to toggle Delta monitor. Right-click input, output, or gain-reduction meters to choose meter display mode. Meter mode and Delta state are monitoring state; they do not redefine the saved gain law.

Example: external low-band key on high-band compression

Route a kick or bass sidechain into the host sidechain input. Focus the high band, set Key to External, and lower threshold until the high band moves when the external source reaches the corresponding split range. Because the external signal is split through the same crossover layout, a high band will not respond strongly to a low-only sidechain unless the crossover layout or detector source is adjusted.

Processing Reference

Ordinary downward compression reduces signal above threshold according to ratio before makeup. For a simple hard-knee example, a signal 12 dB above threshold at 4:1 leaves roughly 3 dB above threshold before makeup. Knee, timing, transfer shape, detector mode, selected Dynamics, and selected Comp change how that simplified relationship becomes audible.

This section uses common compressor vocabulary for threshold, ratio, attack, and release consistent with the JUCE Compressor reference. Filter-shape terms such as low-pass, high-pass, shelf, and Q follow the general terminology used in the W3C Audio EQ Cookbook. The broader digital-audio-effects context is cross-checked against DAFX.

Gate and expander behavior use range dynamics. Range is not ratio. Range limits the maximum attenuation below the open region. Hysteresis or hardness separates open and close behavior so low-level material does not chatter near threshold. In BeePressor, those behaviors are available through compatible Dynamics choices rather than through the Classic Comp list.

ADAA enables antiderivative anti-aliasing for nonlinear or static transfer stages that support it. It is a quality control, not a bypass, tape switch, or generic oversampling selector. Use it when bright or nonlinear material is driven hard. Disable it when lower CPU cost is more important than reduced folded harmonic energy.

The Custom transfer editor uses a threshold-relative X axis. Points and handles describe output relative to input above threshold. Positive signed gain reduction means attenuation. Negative signed gain reduction means upward action or expansion. Non-monotonic curves are possible and should be checked with Delta and the gain-reduction meter.

Envelope timing is applied after detector measurement. Attack controls movement away from neutral gain. Wait delays that movement without stopping detector tracking. Release controls movement back toward neutral. Attack and release shape controls change curve law rather than absolute endpoint value. Auto-release and two-stage release behavior use program movement to change how recovery proceeds after gain reduction.

Hi-Res visualizer mode estimates local spectral content with a 121-band 1/12-octave filter-bank display. It is useful when FFT bin display is too coarse or when detector spillover makes adjacent regions look related. Hi-Res is display analysis and Auto support; it does not alter compression DSP.

A table in this chapter is a lookup surface, not a substitute for the signal-flow model. Read Table 2 as the gain-law family, Table 3 as the Classic compressor character inside one family, Table 4 as band-edge character, and Table 5 as the split/recombine topology. If two rows look like possible solutions, choose the row that changes the layer actually responsible for the symptom.

Table 2. Dynamics topology reference.

Dynamics topology	Technical behavior	Use when	Unsuitable when
Classic compressor	Uses the selected Classic `Comp` model with threshold, ratio, timing, makeup, and optional custom transfer support.	You need predictable compressor behavior inside a band.	The desired result is a gate, expander, spectral process, or adaptive topology.
Lookahead limiter-compressor	Uses delayed audio relative to detector action where supported so gain can respond before a peak reaches output.	You need peak control with fewer missed transients.	Latency is unacceptable or host delay compensation is unavailable.
Upward/downward density	Combines downward action above threshold with low-level density lift below the reference region.	You need sustain or room detail without only shaving peaks.	Noise floor must remain untouched.
RMS leveler into peak limiter	Combines slower average-level control with faster peak containment.	Vocals, bass, dialog, or stems need stable average level.	You need sharp transient character from a single fast detector.
Spectral compressor	Uses frequency-domain gain behavior across spectral bins rather than one ordinary broadband detector law.	Harshness or dense resonance is frequency selective.	You need transparent broadband compression or simple automation mapping.
Causal state-space compressor	Uses bounded causal state to adapt gain behavior over time without an external model file.	Program-dependent adaptive character is desired.	The setting must read like a simple threshold/ratio law.
Noise gate	Uses threshold/range and close/open behavior to reduce material below the gate region.	Bleed, spill, or room tone must close below threshold.	Low-level sustain should remain continuous.
Downward expander	Reduces lower-level material more gradually than a hard gate.	You need separation without abrupt closure.	A strict open/closed gate is required.
Wavelet recruitment compressor	Compares slow carrier energy with fast detail behavior for recruitment-style compression.	You need detail recovery without simple broadband lift.	The source needs ordinary ratio compression only.
Modulation-domain compressor	Uses fast/slow envelope comparison so level control respects modulation depth.	You want control without flattening internal motion.	The desired action is a static EQ or fixed gate.
SNR-aware compressor	Adapts threshold/ratio tendency from a simple signal-to-noise estimate.	Speech or vocal material moves between clear and noisy regions.	Background noise should be brought forward evenly.
Sliding-band compressor	Moves spectral focus toward the active energy centroid and applies strongest action around that focus.	Problem regions move with pitch or articulation.	You require fixed crossover-defined action.
Channel-free compressor	Morphs a wideband law from envelope and spectral-tilt cues rather than using fixed channel metaphors.	You need adaptive wideband behavior without fixed bands inside the topology.	Mid/Side or channel-specific ownership must be explicit inside the law.

Table 3. Classic `Comp` character reference.

Comp	Primary behavior	Timing tendency	Operating consequence
VCA	Clean reference compression with direct threshold/ratio reading.	Tracks user timing closely.	Use as the baseline when diagnosing topology or detector behavior.
FET	Fast, assertive transient grab.	Favors quick attack and controlled release.	Can make threshold movement obvious on drums, vocals, and bright material.
OPTO	Smoother leveling character.	Usually reads slower and more program-smoothed.	Useful where gain motion should be less abrupt.
VARI-MU	Rounded behavior with firmer response under drive.	Broad recovery is often musically useful.	Can add weight while keeping threshold action less clinical.
Tape	Soft compression with saturation density.	Timing interacts with saturation audibility.	ADAA is relevant when the band is driven hard.
Custom	User-shaped transfer curve with point and handle editing.	Envelope remains meaningful unless the curve is static in effect.	Use Delta to verify non-monotonic or reverse regions.
Soft Clip	Static peak rounding above threshold.	Does not use ordinary envelope timing or ratio interaction.	Use ADAA and output metering on bright or exposed sources.

Table 4. Filter character reference.

Filter character	Technical role	Resonance and corner-shift notes
Clean	Neutral band-edge reference.	No added resonant color; use when crossover truth is more important than character.
Moog Ladder	Ladder-style rounded resonant edge.	Resonance can emphasize the edge and make split placement more audible.
SEM	State-variable style character.	Useful for smoother resonant contour around the band edge.
MS-20	Sharper resonant behavior.	Use carefully when detector action already emphasizes transients.
Roland OTA	OTA-style edge character.	Can make band separation read with more synthesizer-like contour.
CEM3320	Integrated filter-chip style edge.	Useful for defined but controlled resonance.
Steiner-Parker	Multimode resonant character.	Good for deliberately audible edge tone.
Twin Peak	Dual-resonance impression near the controlled region.	Can make narrow-band movement more apparent.
CMOS	Harder electronic edge color.	Check Delta when compression and resonance both move strongly.
State Variable	General resonant filter character.	Predictable for technical edge shaping.
Baxandall	Broad, tone-control style contour.	Better for gentle region shaping than narrow resonance.
Passive LC	Passive network style contour.	Can imply broader electrical damping around edges.
Sallen-Key	Active filter cell character.	Resonance changes focus without changing crossover topology.
Diode Ladder	Nonlinear ladder-style color.	Use ADAA and conservative gain when driven hard.

Table 5. Crossover and band topology reference.

Subject	Range or choices	Consequence
Band count	1 to 12 active bands.	Changes the audible split/recombine topology and retargets graph editing.
Crossover range	40 Hz to 18 kHz, with legal spacing between adjacent crossovers.	Prevents impossible or collapsed neighboring bands.
Crossover slope	6, 12, 24, 48, or 96 dB/oct.	Changes separation steepness and interaction between adjacent bands.
Corner shift	-24 to +24 semitones for compatible filter corners.	Moves the character filter corner without moving the actual crossover split.
Inactive band state	Stored for compatibility.	Can reappear when band count expands; it is not audible while inactive.

Operating Procedures

Establish a band layout

1. Set global input so the source enters BeePressor at a sensible level.
2. Choose band count or split from the graph until each active region corresponds to a real production question.
3. Move crossovers before tuning thresholds. A threshold is only meaningful relative to the region that feeds its detector.
4. Choose slopes for separation, not for display symmetry. Steeper slopes reduce overlap but can make isolated band motion more obvious.
5. Select the first band to tune and leave adjacent bands active unless solo is needed for diagnosis.

Tune a focused band

1. Choose Stereo or M/S.
2. If M/S is active, select Mid or Side before editing.
3. Choose Key: Self, internal band, or External.
4. Choose Dynamics.
5. If Dynamics is Classic compressor, choose Comp.
6. Choose Filter and set resonance only if band-edge character is part of the intended sound.
7. Lower threshold until gain movement is visible and audible.
8. Set ratio or range.
9. Set attack, wait, release, and shape controls.
10. Apply makeup only after movement is correct.
11. Use Delta briefly, then return to normal output.

Use Auto and Apply

1. Turn off analyzer Hold.
2. Play a representative passage.
3. Click Auto to start capture.
4. Let enough material pass to describe the source.
5. Click Stop.
6. Right-click Auto to cap maximum bands from 1 to 12 if needed.
7. Click Apply.
8. Review every suggested band manually.

Auto records pre-DSP input spectrum. It does not learn from output meters, Delta, or post-compression analyzer state. Apply writes a starting point; it is not a final mix decision. Treat Auto/Apply as drafting. It can place useful crossovers and starting thresholds, but every suggested band still needs detector, timing, model, filter, makeup, and output review.

Use the five-band detector SC EQ

1. Open the advanced drawer for the focused band/path.
2. Open SC EQ.
3. Enable the detector EQ only when detector selectivity is needed.
4. Use the high-pass to stop low energy from driving unrelated gain movement.
5. Use the bell bands to emphasize or de-emphasize detector regions.
6. Use the low-pass to prevent bright events from driving low or mid control.
7. Turn on detector listen while tuning, then turn it off before final monitoring.

The SC EQ changes the detector. It does not directly equalize the band output. If the tone changes after SC EQ adjustment, the tone changed because gain movement changed.

Use Custom transfer safely

1. Start from conservative threshold and ratio.
2. Choose Custom in the Classic Comp layer.
3. Move points to describe the desired input/output relation relative to threshold.
4. Use segment handles to smooth transitions.
5. Avoid abrupt non-monotonic regions unless the result is intentionally special.
6. Inspect gain-reduction history and Delta.
7. Match output after the curve is stable.

Procedure: diagnose an overactive band

1. Turn Delta on briefly and identify whether the band removes tone, transient, or noise.
2. Check Key. If the detector source is External or another band, the visible audio region may not explain the movement.
3. Check SC EQ and detector listen.
4. Raise threshold before changing release. If movement remains wrong, change detector source or crossover region.
5. Return Delta to normal output and match level with the meter rail.

Presets, State, and Host Behavior

Presets store audio-relevant parameter state and supported editor state. Stable DSP parameters include band count, crossover frequency and slope, threshold, ratio, range where applicable, attack, wait, release, shapes, bypass, solo, dynamics topology, compression model, filter type, resonance, filter-corner shift, makeup, input, mix, output, and ADAA.

Host automation should favor stable controls. Automating band count and crossover layout is valid, but it changes the topology under every dependent band parameter. Automating threshold, ratio, range, makeup, and timing is usually safer for musical movement. Automating crossover movement should be done intentionally because detector range, band filter behavior, and adjacent band balance all change together.

The optional host sidechain depends on host routing. Some hosts expose the sidechain bus only after the plugin is inserted and sidechain input is enabled. External keying changes only the detector source; it does not replace the processed band audio.

Preset links can carry focused band state into compatible BeePlugs products. When a fixed-topology BeeComps identity is pasted into BeePressor, compatible identities map into Dynamics rather than becoming extra Classic Comp models. This preserves the distinction between broad dynamics topology and compressor character.

Meter history, analyzer settings, and Delta are inspection aids. Make final balance decisions with normal output active and the meter rail visible. If a setting seems neutral, confirm global bypass, band bypass, solo, mix, threshold, and range before assuming the preset failed to load.

Troubleshooting

If a band does not respond, confirm it is active, not bypassed, not excluded by solo state, and receiving detector signal. Lower threshold only after confirming the selected Key is correct. In M/S mode, confirm whether the visible controls are editing Mid or Side.

If Auto does not record, disable Hold, confirm input signal, and click Auto again. If Auto creates fewer bands than expected, raise Auto Max Bands and use material with clearer spectral contrast. Auto Max Bands is a cap, not a target.

If External sidechain does not work, check host sidechain routing first. External sidechain is split by the same crossover layout, so a high band will not respond strongly to a low-only external signal.

If shifted filter-corner lines are confusing, remember that the solid crossover is the actual split. Dashed shifted lines are focused character-filter corners. Reset with Command-click on macOS or Control-click on Windows/Linux from the slope chip.

If Delta is silent, processing may be neutral. Global bypass, dry mix, threshold above detector level, range at zero, ratio at neutral, or unchanged transfer can make input and processed output match.

If Hi-Res ignores Bin and Ov, that is expected. Hi-Res uses the filter-bank visualizer instead of FFT bin settings.

If output level jumps after makeup, re-check makeup by band and by M/S path. Makeup is path-specific where the band is in M/S mode.

Research and References

BeePressor's manual references are divided into two groups. Product-truth references describe what the product exposes and how its state is interpreted. Research references support terminology for multiband dynamics, filters, nonlinear transfer, documentation structure, and technical-writing style. When these groups differ, the product-truth references take precedence.

Multiband compression is described here as a split/process/recombine topology because that is the visible operating model in BeePressor. The general literature often explains dynamic range control separately from crossover design, filter response, and metering. BeePressor brings those concepts into one graph, so the manual keeps their responsibilities separate: band topology owns the audible split, Dynamics owns the gain-law family, Comp owns the Classic compressor character, Filter owns edge character, and the detector path owns the signal that drives movement.

Research synthesis. Compressor references support the language of detector, threshold, ratio, attack, release, knee, and gain computer. Filter references support the language of cutoff, Q, resonance, cramping, decramping, and virtual-analog topology. Metering and visualization references support the distinction between inspection and processing. Interface references support direct manipulation, readable graph position, keyboard access, and visible state. None of those sources changes the BeePressor contract; they explain the public terms used to read it.

Table 6. BeePressor research map.

Subject	Primary source basis	Manual use
Product controls and supported behavior	BeePressor project Manual.md; BeeAudioModules public parameter contracts.	Names, ranges, visible labels, stored state, and unsupported-control statements.
Documentation architecture	Diátaxis.	Separation of explanation, procedure, reference, troubleshooting, glossary, and index material.
Technical writing style	Google developer documentation style guide; Microsoft Learn style quick start.	Direct technical nouns, imperative procedure steps, concise definitions, and restrained notes.
Compression vocabulary	JUCE Compressor; JUCE DSP namespace.	Common language for threshold, ratio, attack, release, and DSP processor vocabulary.
Filter terminology	W3C Audio EQ Cookbook.	General terminology for cutoff, Q, shelf, pass filters, and frequency-response discussion.
Digital audio effects context	DAFX.	General context for dynamic range processing, nonlinear transfer, spectral analysis, and audio-effects taxonomy.

The extended bibliography below is deliberately wider than BeePressor's control set. It records the engineering neighborhoods that inform the manual vocabulary: crossover and EQ filter topology, cramping and decramping near Nyquist, virtual-analog filter character, compressor detector design, nonlinear transfer anti-aliasing, metering, spectral display, and graph interaction. Research Table D gives item-level source coverage for the named topologies, compressor characters, filter characters, and graph features described earlier in this manual.

Research Table D. BeePressor item-level source map.

Item	Coverage	Sources
Classic compressor	Threshold, ratio, attack, release, knee, detector, and gain-computer vocabulary.	Giannoulis, Massberg, and Reiss; JUCE Compressor; MathWorks compressor.
Lookahead limiter-compressor	Anticipatory gain movement, latency tradeoff, and peak containment language.	MathWorks limiter; MathWorks dynamic range control; JUCE Limiter.
Upward/downward density	Low-level lift versus ordinary downward compression.	Principles of Digital Dynamic-Range Compression; MathWorks dynamic range control; compressor automation study.
RMS leveler into peak limiter	Average-level control combined with fast peak containment.	compressor design survey; ITU-R BS.1770; EBU R 128.
Spectral compressor	Frequency-domain or bin-local gain behavior and spectral-display vocabulary.	Smith, Spectral Audio Signal Processing; Smith, Mathematics of the DFT; frequency-domain compression overview.
Causal state-space compressor	Stateful adaptive dynamics language without implying external model loading.	state-space compressor modeling; real-time neural compressor modeling; stateful nonlinear audio modeling.
Noise gate	Open/close threshold, range, and chatter-control terminology.	MathWorks noise gate; JUCE NoiseGate; MathWorks dynamic range control.
Downward expander	Below-threshold attenuation that is gentler than hard gate closure.	MathWorks expander; dynamic-range compression principles; compressor design survey.
Wavelet recruitment compressor	Slow carrier and fast detail terminology.	Mallat wavelet representation; wavelet packet audio coding; spectral audio processing.
Modulation-domain compressor	Fast/slow envelope and modulation-depth language.	speech modulation analysis; joint acoustic and modulation frequency analysis; spectral-temporal cues in sound perception.
SNR-aware compressor	Noise-aware adaptation and speech/noise contrast terminology.	Ephraim and Malah speech enhancement; a priori SNR estimation review; SNR estimation in speech enhancement.
Sliding-band compressor	Spectral centroid and moving-frequency focus language.	spectral centroid perception study; spectral analysis reference; spectral descriptors review.
Channel-free compressor	Adaptive wideband law and non-channelized control vocabulary.	DAFX; dynamic-range processor taxonomy; signal-dependent speech features.
VCA	Clean controlled-gain compressor behavior and baseline timing terminology.	compressor design survey; MIT compression notes; JUCE Compressor.
FET	Fast transient-grab compressor language.	1176 technical manual; compressor design survey; MathWorks compressor.
OPTO	Optocoupler memory and smoother program response language.	optocoupler compressor modeling; optical compressor modeling; compressor design survey.
VARI-MU	Drive-dependent compression and nonlinear control-stage vocabulary.	MIT compression notes; DAFX; compressor design survey.
Tape compression	Soft saturation, nonlinear transfer, and anti-aliasing context.	ADAA with frequency compensation; nonlinear Volterra antialiasing; DAFX nonlinear effects.
Custom compression	Static transfer, non-monotonic curve, and gain-law terminology.	static characteristic discussion; ADAA circuit interpretation; JUCE Compressor.
Soft clip	Static clipping and nonlinear alias-risk language.	ADAA; nonlinear Volterra antialiasing; DAFX.
Clean filter	Neutral digital-filter and crossover vocabulary.	Smith digital filters; W3C Audio EQ Cookbook; All About Audio Equalization.
Moog Ladder	Ladder-filter resonance, feedback, and nonlinear edge vocabulary.	Stilson and Smith; Huovilainen; D'Angelo and Valimaki.
SEM	Multimode and state-variable-style filter language.	Simper SVF outputs; Chamberlin SVF improvement; Zavalishin VA filters.
MS-20	Active-filter resonance and driven cutoff-edge vocabulary.	Zavalishin VA filters; Sallen and Key filter; Smith physical audio systems.
Roland OTA	OTA and Gm-C filter terminology.	OTA active filters; TI OTA application note; OTA filter design.
CEM3320	Integrated voltage-controlled filter and chip-filter vocabulary.	CEM3320 datasheet; CEM3320 VCF datasheet copy; AS3320 datasheet.
Steiner-Parker	Multimode resonant filter vocabulary.	VA filter design; physical audio signal processing; digital filter fundamentals.
Twin Peak	Dual-resonance and multiple-peak contour vocabulary.	Smith digital filters; MathWorks peak analysis; VA filter design.
CMOS	CMOS and Gm-C filter terminology for electronic edge color.	digitally tunable Gm-C filter; OTA universal filter; TI OTA note.
State Variable	SVF resonance and multimode-output terminology.	SVF simultaneous outputs; optimized trapezoidal SVF; Chamberlin SVF improvement.
Baxandall	Broad tone-control contour and shelf-like vocabulary.	Baxandall original tone-control article; W3C EQ Cookbook; audio EQ survey.
Passive LC	Passive resonator and network-damping language.	physical audio signal processing; digital filters; VA filter design.
Sallen-Key	Active two-pole filter cell vocabulary.	Sallen and Key; Smith digital filters; W3C EQ Cookbook.
Diode Ladder	Nonlinear ladder and resonant feedback vocabulary.	D'Angelo and Valimaki; Huovilainen; nonlinear antialiasing context.
Band count and crossovers	Split/process/recombine and multiband topology language.	Cadenza multiband compressor tutorial; MathWorks crossover digital filter; multi-channel compression overview.
Crossover slope	Filter-order and transition-steepness terminology.	Orfanidis high-order EQ; MathWorks crossover digital filter; Smith digital filters.
Corner shift and decramping	Semitone offset, high-frequency warping, and decramped-filter vocabulary.	Orfanidis prescribed Nyquist gain; Vicanek matched filters; FAUST decramped filters.
Five-band detector SC EQ	Detector-only EQ and parametric filter terminology.	W3C EQ Cookbook; MathWorks designParamEQ; audio EQ survey.
Auto/Apply	Capture, suggested settings, and editable compressor-starting-point language.	compressor automation study; multiband compression example; Cadenza multiband compression.
ADAA	Nonlinear transfer anti-aliasing terminology.	ADAA with frequency compensation; ADAA circuit interpretation; Volterra-model antialiasing.
Hi-Res visualizer	Spectral analyzer, filter-bank, DFT, and octave-spaced reading vocabulary.	spectral audio signal processing; Mathematics of the DFT; spectral perception reference.
Meter history and Delta	Level, difference monitoring, and inspection-state vocabulary.	ITU-R BS.1770; EBU R 128; Victor, Magic Ink.
Graph interaction	Direct manipulation, graph perception, and accessible continuous-control vocabulary.	Cleveland and McGill; Shneiderman direct manipulation; WCAG 2.2.

Research Table A. Filter topology, EQ, and decramping references.

Reference	Subject	Manual use
Smith, Introduction to Digital Filters with Audio Applications	Digital filter fundamentals.	General language for poles, zeros, cutoff, resonance, phase, and implementation consequences.
Smith, Physical Audio Signal Processing	Physical and virtual audio systems.	Context for virtual analog, resonator, and filter-model terminology.
W3C Audio EQ Cookbook	Biquad EQ forms.	Shared terminology for bell, shelf, high-pass, low-pass, Q, bandwidth, and gain.
Valimaki and Reiss, All About Audio Equalization	EQ research survey.	Reference for EQ taxonomy, equalization use cases, and current research framing.
Orfanidis, Digital Parametric Equalizer Design with Prescribed Nyquist-Frequency Gain	High-frequency EQ behavior.	Background for cramping and decramping language near Nyquist.
Orfanidis, High-Order Digital Parametric Equalizer Design	Higher-order parametric EQ.	Context for sharper band edges and high-order EQ families.
Vicanek, Matched Second Order Digital Filters	Matched and decramped second-order filters.	Reference for alternatives to ordinary bilinear-transform cramping.
FAUST vaeffects library notes	Virtual analog and decramped filter implementations.	Implementation vocabulary for matched filters without treating BeePressor as a FAUST product.
MathWorks designParamEQ reference	Parametric EQ design interface.	Terminology for gain, center frequency, bandwidth, order, and cascade behavior.
A pre-distortion based design method for digital audio graphic equalizer	Predistortion and equalizer accuracy.	Additional context for cramping correction and high-frequency accuracy.
Matrix-based design and realization of digital parametric equalizer	Parametric EQ realization.	Context for cascade and filter-structure distinctions.
Zavalishin, The Art of VA Filter Design	Virtual analog filters and zero-delay feedback.	Vocabulary for virtual-analog filter character and topology behavior.
Stilson and Smith, Analyzing the Moog VCF for Digital Implementation	Moog ladder discretization.	Research background for ladder-filter references such as Moog Ladder and Diode Ladder.
Huovilainen, Non-Linear Digital Implementation of the Moog Ladder Filter	Nonlinear ladder modeling.	Context for nonlinear resonant ladder terminology.
D'Angelo and Valimaki, Generalized Moog Ladder Filter Part II	Delay-free loop ladder modeling.	Background for nonlinear filter topology and feedback-loop wording.
Lazzarini and Timoney, Improving the Chamberlin Digital State Variable Filter	State-variable filters.	Context for State Variable and SEM-like multimode filter language.
Simper, Simultaneous Solving of Linear SVF Outputs	Trapezoidal SVF outputs.	Reference for simultaneous multimode output vocabulary.
Simper, Linear Trapezoidal Integrated SVF	Optimized state-variable filters.	Reference for topology, resonance, and numerical behavior in audio SVF designs.

Research Table B. Dynamics topology, nonlinear transfer, metering, and spectral references.

Reference	Subject	Manual use
Giannoulis, Massberg, and Reiss, Digital Dynamic Range Compressor Design	Compressor design survey.	Baseline terminology for peak/RMS detection, feedforward/feedback design, knee, attack, and release.
Giannoulis, Massberg, and Reiss, Parameter Automation in a Dynamic Range Compressor	Automatic compressor parameter setting.	Research context for Auto/Apply as capture plus editable starting state.
Principles of Digital Dynamic-Range Compression	Broadband, multichannel, side-branch, and spectral compression.	Context for multiband and spectral dynamics distinctions.
MathWorks Dynamic Range Control	Compressor, expander, limiter, and gate vocabulary.	Cross-check for range dynamics and gate/expander descriptions.
FAUST compressors library	Compressor function taxonomy.	Vocabulary comparison for common digital compressor controls.
JUCE Compressor	Compressor control vocabulary.	Common naming for threshold, ratio, attack, and release.
JUCE DSP namespace	DSP module vocabulary.	General terminology for processor families, filters, and audio blocks.
Antiderivative Antialiasing with Frequency Compensation for Stateful Systems	ADAA variants.	Context for ADAA wording in nonlinear and stateful stages.
An Equivalent Circuit Interpretation of Antiderivative Antialiasing	ADAA circuit interpretation.	Background for treating ADAA as anti-aliasing rather than a tone switch.
Antialiasing for Simplified Nonlinear Volterra Models	Nonlinear alias reduction.	Context for nonlinear transfer and aliasing risk.
Efficient neural networks for real-time modeling of analog dynamic range compression	Neural compressor modeling.	Background for adaptive and state-style compressor terminology without claiming external model loading.
Modeling Analog Dynamic Range Compressors using Deep Learning and State-space Models	State-space and neural compressor modeling.	Context for stateful compressor descriptions.
Cadenza multiband compressor tutorial	Multiband compression tutorial.	Terminology for split bands and per-band dynamics.
Smith, Spectral Audio Signal Processing	FFT, STFT, and spectral analysis.	Reference for FFT/Hi-Res display vocabulary.
Smith, Mathematics of the DFT	DFT and FFT foundations.	Background for analyzer and spectral-bin descriptions.
ITU-R BS.1770	Loudness and true-peak measurement.	Metering context; BeePressor meters are product meters, not broadcast conformance claims.
EBU R 128	Loudness normalization.	Context for loudness terminology and why meter labels must be specific.

Research Table C. GUI, graph, and technical-documentation references.

Reference	Subject	Manual use
Apple Human Interface Guidelines, Sliders	Continuous controls.	Context for graph handles, slider direction, and value feedback.
GNOME Human Interface Guidelines, Sliders	Slider use and exact-value pairing.	Context for graph gestures paired with numeric readouts.
JUCE Slider	Plugin control implementation vocabulary.	Reference for common audio-plugin control labels and accessibility hooks.
JUCE AccessibilityValueInterface	Accessible values.	Context for exposing parameter value meaning beyond drawing.
JUCE Colours tutorial	Component color assignment.	Context for product-colored graph accents and contrast restraint.
JUCE Label tutorial	Control labels.	Context for chip labels and attached control text.
WCAG 2.2	Accessibility requirements.	Reference for contrast, focus, target size, and keyboard-accessible manual pages.
WAI-ARIA Authoring Practices Guide	Keyboard widget behavior.	Context for browser-side manual navigation and graph-like controls.
Cleveland and McGill, Graphical Perception	Quantitative graph decoding.	Reference for readable position, length, and slope encoding in graph displays.
Tufte, The Visual Display of Quantitative Information	Data graphics.	Context for restrained graph presentation and avoiding decorative display noise.
Shneiderman, Direct Manipulation	Direct manipulation principles.	Context for immediate visible feedback from graph gestures.
Shneiderman, Direct Manipulation for Comprehensible, Predictable and Controllable User Interfaces	Predictable direct manipulation.	Research support for reversible graph editing and visible state.
ISO 9241-110 interaction principles	Human-system interaction.	High-level context for suitability, controllability, and self-descriptiveness.
Victor, Magic Ink	Information software.	Context for showing state and measurement before asking the user to operate controls.
Diátaxis	Documentation architecture.	Reason for separating explanation, procedure, reference, troubleshooting, glossary, and index.
Google developer documentation style guide	Technical writing.	Basis for direct wording, active voice, and predictable terminology.
Microsoft Learn style quick start	Technical style.	Basis for concise procedures and reader-focused reference sections.

Auto/Apply is documented as a procedure and as a state rule rather than as a promise of a finished mix because capture, suggestion, and Apply are separate operator actions. Hi-Res, FFT, Delta, and meter history are documented as inspection systems because they help evaluate a setting without changing the gain law themselves.

Endnotes

1. The source basis for this website manual is BeePressor project Manual.md, plus public BeeAudioModules parameter and label contracts used to verify product names, visible controls, ranges, supported behavior, and omitted behavior.
2. BeePressor behavior is defined by the local product manual and the public parameter, label, and state contracts. External works are used for terminology and general audio-DSP context only.
3. The chapter order follows explanation, procedure, reference, troubleshooting, glossary, and index divisions so operating instructions do not obscure topology descriptions or lookup material.
4. Research sources support the language used for filters, compressor topologies, dynamic range control, decramping, metering, graph interaction, and technical documentation. They are not claims that the products implement any cited algorithm exactly.

Bibliography

• Local product source: BeePressor project Manual.md.
• Local product source: BeeAudioModules public parameter and label contracts.
• Diátaxis documentation framework.
• Google developer documentation style guide.
• Microsoft Learn style quick start.
• W3C Audio EQ Cookbook.
• DAFX: Digital Audio Effects.
• JUCE Compressor class reference.
• JUCE DSP namespace reference.

Reference Tables

Table 7. Parameter families and ownership.

Family	Primary controls	Meaning
Multiband topology	Band count, split/remove, crossover frequency, slope.	Defines the audible band layout.
Dynamics topology	`Dynamics`.	Defines the broad gain-law family for the focused band.
Classic character	`Comp`.	Defines compressor model behavior when `Dynamics` is Classic compressor.
Filter character	`Filter`, resonance, corner shifts.	Defines band-edge color and shifted edge placement for the selected path.
Detector	Key, detector mode, RMS window, stereo link, external blend, SC EQ.	Defines what level is measured and how it is measured.
Timing	Attack, wait, release, shapes, auto-release, envelope scale.	Defines how gain moves after detector measurement.
Inspection	Delta, meters, meter history, visualizer, Hi-Res.	Shows or auditions processing behavior without defining the core gain law.

Table 8. Monitoring and visualizer reference.

Monitor	Reads	Use for	Limit
Input meter	Incoming signal level.	Input gain staging.	Does not show post-processing level.
Output meter	Processed output after mix/output gain.	Level matching and clipping avoidance.	Does not explain which band caused movement.
Gain-reduction meter	Current attenuation or movement.	Compression amount and timing behavior.	Can be neutral when static tone still changes.
Meter history	Recent gain-reduction movement over time.	Release and program-motion diagnosis.	History is not an audio processor.
FFT visualizer	Input spectrum by FFT bins.	Narrow peaks and fast spectral detail.	Bin and overlap affect display, not DSP.
Hi-Res visualizer	121-band 1/12-octave filter-bank estimate.	Musically spaced contour and Auto support.	Not a higher-quality processing mode.
Delta monitor	Input minus processed output.	Hearing exactly what changed.	Not the final monitoring state.

Glossary

Active band

A band inside the current band count and crossover topology.

ADAA

Antiderivative anti-aliasing for compatible nonlinear or static transfer evaluation.

Corner shift

A filter-character offset that moves a focused edge relative to the crossover without moving the crossover itself.

Detector listen

A monitoring mode for hearing the detector signal after detector routing and detector-only EQ.

Range dynamics

Gate or expander behavior where maximum attenuation is controlled by range rather than ordinary ratio alone.

Index

ADAA: Processing Reference; Research and References; Reference Tables. Auto/Apply: Interaction Rules; Operating Procedures; Research and References. Compressor topology: Processing Reference; Research and References. Cramping and decramping: Research and References. Custom transfer: Processing Reference; Operating Procedures. Detector routing: System Description; Control Surface; Research and References. Filter character: Processing Reference; Research and References; Reference Tables. GUI design: Research and References. Hi-Res: Processing Reference; Research and References; Reference Tables. M/S: System Description; Operating Procedures. Meter history: Feature Inventory; Reference Tables. Endnotes: Feature Inventory; Processing Reference; Research and References.