Biquadia: Audio & DSP Lab

Biquadia is an acoustic engineering and audio analysis lab designed for audio engineers, researchers, and sound designers. It brings real-time DSP, acoustic measurement, spectral visualization, and spatial analysis directly to iOS and iPadOS. [IN-APP PURCHASE DISCLOSURE] Biquadia includes powerful core features completely free of charge. Advanced features marked below with [Requires In-App Purchase] require a Biquadia Pro subscription (Monthly with a 7-day free trial) or a Lifetime Purchase. FREE FEATURES INCLUDED: • DSP Lab: Real-time FIR/IIR filtering, parametric EQ, dynamics processing, live oscilloscope, and FFT spectrum analyzer. • Analysis Lab: High-resolution FFT, pitch tracking, formant estimation, and real-time STFT spectrogram. • Measurement Lab: Multi-sweep acoustic measurements, impulse response capture, and calibrated SPL analysis. • Psychoacoustics & Codec Lab: Codec difference spectrograms, perceptual masking thresholds, and Bark/Mel scale overlays. • Audio FX & Signal Generator: Sine, frequency sweeps, pink/white noise generator, plus chorus, drive, and delay visualization. • System & Audio Hub: System performance diagnostics, multi-channel I/O mixer, and live signal routing meters. PRO FEATURES [REQUIRES IN-APP PURCHASE]: • Target-Speaker Extraction [Requires In-App Purchase]: Experimental on-device Core ML model that isolates one enrolled voice from a mixture using its speaker embedding — a technology demonstration, not a general-purpose noise remover. • Advanced Array Processing [Requires In-App Purchase]: Covariance-based MVDR beamforming for multi-microphone arrays (up to 32 channels). • Ambisonics & Spatial Audio [Requires In-App Purchase]: First-Order Ambisonics (FOA) encoding, 3D scene rotation, and binaural room impulse response decoding. • Measurement Data Export [Requires In-App Purchase]: CSV export of per-band THD+N/SNR measurement data. IN-APP PURCHASE OPTIONS: - Biquadia Pro Monthly: $4.99/month (Auto-renewable subscription with a 7-day free trial). - Biquadia Pro Lifetime: $79.99 (One-time non-consumable purchase). Biquadia processes audio entirely on-device. It has no developer-operated backend, telemetry, or audio upload. Network activity is limited strictly to Apple StoreKit and user-selected external links. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/