Precision Acoustics Through Dual-Driver Design
Core Innovation
Employing dedicated woofer-tweeter units (two-way design), Donut surpasses single full-range drivers with:
✅ 30% wider dynamic range
✅ 55% lower THD (Total Harmonic Distortion)
The 150–500 Hz range is a critical low-mid band to which human hearing is most sensitive — any crossover, phase, or transient mismatch can cause “frequency gaps” or “low-frequency smearing.”
The Challenge: Bass Loss & Algorithmic Overcompensation
1. Frequency Gaps
Single-driver systems have almost no response below 40 Hz, resulting in a lack of immersion for ultra-low-frequency effects such as deep-sea whale calls or thunderstorms.
2. Limited Conventional Algorithms
Typical algorithms simply boost <60 Hz, which can cause waveform distortion and enclosure resonance, resulting in humming noise floors and energy build-up.
Our Solution: Integrated Hardware & Software Optimization
Software Acoustic Tuning: Deep Yet Controlled Bass
•Adaptive Bass Contour: Real-time adjustment of 20–120 Hz gain based on SPL;
•Boosts at low volumes, keeps vocal range linear, reserves 6 dB headroom for large dynamics.
•Transient Recovery: DSP-level envelope reconstruction with <0.5 s attack delay to suppress “popping” artifacts.
•Sleep-Loudness Match: In sleep mode, <40 Hz fades following Fletcher–Munson equal-loudness curves for natural perception.
Hardware Structural Optimization: Eliminating Tactile Noise
•Bass enclosure lined with high-density damping pads + localized acoustic coating, attenuating the 150 Hz resonance peak by 6 dB.
•Crossover point between high & low drivers raised to 2800 Hz with 4-pole notch phase compensation to prevent mid-low energy collapse.
•Micro-guide ribs in the port reduce secondary reflections above 400 Hz.
Test conditions: Free-field environment, 23 ± 2 °C, microphone at 1 m distance, calibration per IEC 60268-5:2020.
Through the dual synergy of physical acoustics and proprietary DSP algorithms, Donut achieves smooth 50 Hz–20 kHz full-band integration within a two-way design. The bass is deep yet restrained, enabling a wider dynamic range and lower background noise for the Sound–Light Breathing Mode.
Users don’t just hear the rhythm — they can feel the entire device breathing in sync, laying a solid foundation for immersive multimodal rhythmic experiences.