Speaker Time Alignment — Phase Coherence
Speaker time alignment adjusts electronic delay so loudspeakers arrive simultaneously at listener positions, ensuring constructive summation. Proper alignment matches both time arrival and phase, verified via transfer function per AES-2id.
Why Alignment Matters
1 ms offset creates first null at 500 Hz. Alignment achieves up to 6 dB coherent gain vs 3 dB incoherent. Sound travels 343 m/s at 20 degrees C.
Process
Step 1: Verify polarity (impulse peak positive). Step 2: Set delay from IR peak positions. Step 3: Verify with transfer function (smooth summation, phase convergence, high coherence).
Subwoofer Alignment
Critical because long wavelengths. At 100 Hz, half-wavelength = 1.7 m = 5 ms for cancellation. Gradient method optimizes phase slope through crossover.
Temperature
Speed changes 0.6 m/s per degree C. 10-degree change shifts delay 0.3 ms over 17 m. Re-verify after temperature changes above 5 degrees.
Try It Now
Align speakers with transfer function