Quote:
Originally Posted by David Rick  In this case, you have two EQ's that aren't set the same, whatever the markings on the user controls say. An ideal EQ is a linear device, and if it is minimum phase then there is a one-to-one correspondence between impulse response and frequency response. So if you see that the impulse response is different, then so is the frequency response. |
Hi David,
That was my exact assumption before I made the measurements that Holger is referencing above. I can assure you that this assumption is incorrect. In fact, it was because of differences in audible artifacts I was "hearing" that prompted me to make these measurements in the first place. In particular, Logic's Channel EQ. Many have heard that one "sing". There must be "something" these designers are doing that creates this.
Anyway, if you check my site you'll see that I set up the same filter response for all measurements. In fact, I made sure the difference in the transfer functions were within 0.1dB. Yes, it took a while to set all these up, but I was a man on a mission!
Here's my EQ page. Quote:
Originally Posted by David Rick Why wasn't the difference audible in your case? Well, maybe the extra "hang-over" in the impulse response was masked by something else in the music. Or (if you were actually listening to the test signal), maybe the difference was simply below your psychoacoustic "just noticeable difference limen". |
Agreed! The audibility of these artifacts is extremely dependent on signal content and are easily masked in the presence of sustained waveforms. However, with the right transient or fast gated signal, it becomes entirely audible.
Interestingly, even though the Flux EQ exhibits worse measured characteristics than many, it is still no where near the Logic Channel EQ in audibility. Generally speaking, it's a great sounding EQ. As I mention on the page, these measurements shouldn't be used as a sole criteria for selecting an EQ, but it is important to keep these characteristics in mind for mix troubleshooting.
fader8