if i can zoom in so that i'm essentially looking at them under a microscope and see absolutely no change when switching between them (nor hear it), and see absolutely no small variation between their frequency responses no matter which identical segments i analyze, i can hardly say that there is any random excitation. it should measurable but it's just not there. i even used a linear phase eq to filter everything out below ~1khz to remove any masking caused by the lower freqs, and still couldn't hear anything. i zoomed in on both files again and could zoom in even further now, and still saw no difference in amplitude anywhere. you're just assuming that it's there because when you null things there is stuff left over. one .wav having material the other doesn't isn't the only way to have something left over after a null. phase differences will leave stuff behind too, even if both wavs have almost identical content.
that's what i think is going on. peak and rms will have different attack timing, with peak catching transients and RMS not, and a phase difference caused by the attacks would leave the transients after null between peak/raw. which is what it does. so the leftover is some higher freq stuff left from the transients. it's probably also a little frequency specific which is why it sounds a little like distortion. if you null between 15ms and 30ms using RMS both times, there is still leftover stuff but now its the body of the drums after the transients. because that's what falls in that time range. but with that leftover you can hear better that it isn't any kind of distortion, it's just that part of the drums.
the nulls in this latest test you did, in my mind, demonstrate what i'm saying about the phase difference. both nulls have it though. yes, the one between peak and raw is louder. but it's only about 7db louder on average. to me the explanation is that it's louder because transients are louder, and because peak mode has the faster attack, so it's attack stage is happening earlier, during the transients, and the phase shift caused by the attack is happening during the transients, so the null leaves them. with the rms/raw null the transients aren't there because RMS doesn't detect them, which is what i was saying in the first place. the attack doesn't kick in until the body of the drum, so that's what's in this null. and that's why this null is quieter, because the body is lower than the transients.
i would but if you can only measure the transient excitement by doing a null test then you aren't conclusively proving that it's there. phase difference leaves stuff behind after a null too. the fact that the 'transient excitement' cannot be seen on the processed files before null no matter how close you look at them or how you analyze tells me that it's probably subtle phase shifting.yr wrote: I'm pretty sure that if you bought a new "clean" preamp or A/D converter and realized that it has a built-in random transient exciter (as "peak" mode does) you would send it back to the manufacturer...
i would word it that the rms version just isn't handling the transients at all, which is common knowledge about rms and exactly what should be expected with nebula. i agree that it's phase distortion/shifting, which is what i've been saying, but i don't agree that peak is worse than RMS, because they both do it. the difference is that it happens quicker with peak because peak actually catches the transients, where RMS doesn't. besides that, whats left after null is like over 60db below the original level in each case. if that were added harmonic distortion at that level it would be pretty bad, but if it's because of phase shifting it's not that bad. i think this is evidenced in the fact that it's always been there but people still love nebula. it's always there, no matter which mode you use or which attack time you use, and it's always about the same level below the original (if you compare identical tiny sections after null to the same sections before to not have bias due to transients being louder). in my mind all this has shown is that peak mode places it earlier, in the transient, because peak mode actually catches the transients just like i said it would, whereas RMS doesnt.yr wrote: Just did another test using a clean (no thd), flat freq preset and I'm pretty much convinced that "peak" mode's handling of transients is worse then the rms mode (be it phase distortion or any other artifact).