Project Modes

LinFIR offers two specialized operating modes, each designed for specific audio engineering workflows. The mode is selected during project creation and determines the available features and interface elements throughout the project’s lifetime.

Loudspeaker Design Mode

Purpose

This mode is optimized for designing and analyzing multi-way loudspeaker systems. It provides comprehensive tools for crossover design, driver integration, and directivity analysis.

Key Features

• Multi-driver support: Design systems with multiple drivers (subwoofers, woofers, midranges, tweeters)
• Crossover: FIR and IIR crossover filters with various types
• Driver correction: Individual magnitude and phase correction for each driver
• Directivity tools: Analyze off-axis response and polar patterns (license required)
• Complete export: Export individual driver filters, global filters, and HFD configurations

Typical Workflow

1. Create a new Loudspeaker Design project
2. Import or measure impulse responses for each driver
3. Design crossover filters (low-pass, high-pass)
4. Apply frequency response corrections
5. Analyze summed system response
6. Export filters for DSP implementation

When to Use

• Designing passive loudspeaker conversions to active DSP
• Optimizing existing multi-way systems
• Analyzing driver interactions and phase relationships
• Creating custom crossover
• Performing anechoic or quasi-anechoic measurements

Room Calibration Mode

Purpose

Dedicated to in-room acoustic measurements and correction filter generation. This mode focuses on capturing multiple measurement positions, aligning them temporally, and creating averaged correction filters.

Key Features

• Multiple measurement positions: Capture IRs at different listening locations
• Automatic temporal alignment: GCC-PHAT algorithm aligns measurements
• Spatial averaging: Creates averaged response across measurement positions
• Global correction only: Simplified interface focused on room correction
• Streamlined export: Export only global correction filters

Typical Workflow

1. Create a new Room Calibration project
2. Configure sweep output channel
3. Capture measurements at 3-5 different listening positions
4. Measurements are automatically aligned using GCC-PHAT
5. Design global correction filters (FIR and/or IIR)
6. Export correction filters for room EQ implementation

UI Adaptations

When in Room Calibration mode, the interface adapts to focus on relevant features:

• Disabled: Directivity analysis tools (not applicable to room measurements)
• Simplified: Filter graphs show only global filters
• Restricted: Export options limited to global correction filters
• Hidden: Individual driver processing controls

Export Restrictions

Room Calibration projects export only:

• Global FIR correction filter (if enabled)
• Global IIR filters (Manual or Auto-EQ)

The following exports are disabled:

• HFD config export
• Detailed reports (TXT/PDF)
• Individual driver filters

This ensures clean, focused output for room correction workflows.

When to Use

• Correcting in-room frequency response
• Creating stereo-linked or mono room correction
• Working with existing loudspeaker systems
• Integrating with convolution engines

Mode Selection

Creating a New Project

Project mode is selected via File → New Project:

1. Click “New Project”
2. Choose between “Loudspeaker Design” and “Room Calibration”
3. Configure initial project settings (sample rate, filter length, etc.)
4. Begin working in the selected mode

Mode Permanence

⚠️ Important: Once a project is created, its mode cannot be changed. The mode is permanently associated with the project file.

To work in a different mode:

1. Save your current project (if needed)
2. Create a new project with the desired mode
3. Import measurements or data as required

Choosing the Right Mode

Use Loudspeaker Design Mode when:

• Designing crossovers for multi-driver systems
• Analyzing individual driver characteristics
• Performing directivity analysis
• Exporting filters to Hypex FA amplifiers
• Working with anechoic or quasi-anechoic data

Use Room Calibration Mode when:

• Correcting in-room frequency response
• Creating averaged room correction filters
• Working with existing complete loudspeaker systems
• Focusing on global system correction only

Best Practices

Room Calibration Mode

• Measurement count: Capture 3-5 measurements at different positions
• Position spacing: Keep positions within 30-50 cm of main listening area
• Height consistency: Use consistent microphone height across measurements
• Reference position: First measurement should be at primary listening position
• Correction philosophy: Apply gentle correction, avoid over-equalization
• Deep nulls: Don’t attempt to fill room mode nulls below 300 Hz
• Phase type: Consider minimum-phase FIR for reduced latency
• Acoustic treatment: Combine with room treatment for best results

Loudspeaker Design Mode

• Measurement quality: Use anechoic or quasi-anechoic measurements when possible
• Windowing: Gate reflections using IR time windowing
• Alignment: Align drivers using time delay controls, not FIR compensation delay
• Crossover design: Start with appropriate crossover frequencies and filter slopes
• Phase analysis: Monitor phase relationships between drivers
• Directivity: Capture multiple angles for comprehensive analysis (license required)

Mode Comparison Table