Quote:
Originally Posted by
Rymdis
β‘οΈ
So Minimal Phase EQ's are all the ones that are NOT Linear Phase or?
Are for example the URS series and the Waves REQ's "Minimal Phase"?
It's "minimum" phase, not "minimal." Non linear phase EQs are indeed minimum phase. The "why" of the term "minimum phase" is beyond the scope here, so lets stick to linear/non-linear phase EQ.
Minimum phase, or IIR filters (Infinite Impulse Response) suffer from group delay, where certain groups of frequencies lag behind others. Not all the signal arrives at the same time. This phase distortion is a necessary part of the equalization in these types of filters.
Linear phase, or FIR filters (Finite Impulse Response) fix this problem so that all frequencies arrive at the same time. Phase distortion is not eliminated, it is simply made linear, meaning that all frequencies are delayed by the same amount. In other words, the signal has a small delay. However, with these filters you suffer from the added problem of pre-echo, aka pre-ringing.
As some less common examples, you technically could create a minimum phase FIR filter, and you can use a special dual-pass IIR process to make linear phase EQ (one pass for the EQ, and a reverse pass to correct for the phase response), but these are the exception, not the rule.