Linear-phase EQ
Linear-phase EQ is an equalizer that uses an FIR (Finite Impulse Response) filter algorithm to prevent phase distortion.
Phase distortion is a phenomenon that occurs when the phase of a signal is not constant across frequency bands. Phase distortion can make the sound of a signal sound unnatural or awkward.
FIR filters are filters that approximate an infinitely wide frequency band, and they have the characteristic of not causing phase distortion.
Linear-phase EQs have the advantage of being able to create transparent sound because they do not cause phase distortion. They are especially used in mastering work because phase distortion can disrupt the overall balance of sound in mastering work.
Linear-phase EQs have the following advantages and disadvantages.
Advantages
- Can create transparent sound by not causing phase distortion.
- Phase is constant across frequency bands, so phase distortion does not occur even if multiple equalizers are used.
Disadvantages
- Causes latency.
- Pre-ringing may occur.
Latency is the delay time that occurs when a signal passes through an equalizer. Linear-phase EQs use FIR filters, so a constant latency occurs during filtering depending on the sampling frequency.
Pre-ringing is a small ringing phenomenon that occurs just before the transient of a signal. Linear-phase EQs use FIR filters, so pre-ringing may occur during filtering.
Linear-phase EQs are suitable for cases where you want to create transparent sound because they do not cause phase distortion. However, it is important to note that latency and pre-ringing may occur.
Additional information
Linear-phase EQs are often used in mastering work because they can preserve the original sound of a signal. However, they can also be used in mixing work to create a more transparent sound.
When using a linear-phase EQ, it is important to be aware of the latency and pre-ringing effects.