Equalization (EQ)
Definition
Equalization (EQ)
Equalization (EQ) is the process of adjusting the amplitude of specific frequency bands in an audio signal to correct frequency response deviations, compensate for room acoustics, or shape tonal character. Professional sound systems use parametric, graphic, and shelving equalizers to optimize response. SonaVyx guides EQ decisions with measurement data showing frequency response deviations and coherence quality.
How It Is Measured
EQ effectiveness is verified by measuring the system frequency response before and after adjustment using SonaVyx transfer function or RTA mode. The before/after comparison confirms that EQ corrections achieve the intended result without introducing new problems. SonaVyx coherence data guides which frequencies are appropriate for EQ correction (high coherence) versus those that should not be equalized (low coherence indicating room reflections).
Practical Example
A PA system transfer function shows +6 dB excess at 200 Hz and -4 dB deficiency at 3.5 kHz. SonaVyx coherence is high (above 0.85) at both frequencies, confirming these are correctable deviations. The engineer applies a -6 dB parametric cut at 200 Hz (Q=2) and a +4 dB boost at 3.5 kHz (Q=3). Post-EQ measurement confirms the response is within ±2 dB of the target curve.
Corrective vs Creative EQ
System EQ corrects deficiencies in the speaker-room interaction to achieve flat or target response. It is applied to the system output and affects all sources equally. Channel EQ shapes individual input signals for artistic purposes. These serve fundamentally different functions — system EQ is measurement-driven, while channel EQ is ear-driven. SonaVyx supports the measurement-driven system EQ process.
EQ and Coherence
The cardinal rule of data-driven EQ: only apply EQ corrections at frequencies where coherence is high. Boosting a frequency with low coherence amplifies noise and reflections without improving the direct sound. Cutting a frequency with low coherence may reduce problems in some directions but create new ones in others. SonaVyx color-codes coherence to guide these decisions in real time.
Common Mistakes
Over-equalization is the most common mistake — applying too many narrow corrections that fight against room physics. Boosting to fill nulls caused by comb filtering is counterproductive because the null position depends on listener location. Using graphic EQ when parametric is more appropriate wastes bands on fixed frequencies that do not match the actual problems. SonaVyx helps avoid these mistakes by showing what can and cannot be corrected.
Try It Now
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