Serious Confusion - HUGE Low End Timing Issue

Cubase
,
1

Many probably haven’t noticed this yet. It may simply be the properties of sound in general. If not a serious error is at play. I beg anyone to follow along and help me get to grips with this issue. When it comes to a perfect mix this is HUGE!

I stumbled across this when observing the waveform of the mix, in Volume Shaper, on the Master. I wanted to visually see how tight i could get the tail of the kick and the start of the release ducking the sub, before they interact too much. I’ve started do this in all my projects. In some i noticed the transient of the kick was behaving erratically, even though i knew i had the sub 100% ducked at that point. When muting the kick, sure enough, a tiny bit of the sub is visible at the start on the Volume Shaper, acting as a display, on the Master.

What is happening here is, when inserting certain plugin, possibly delay related, either the sub is shifting back or the ducking is shifting back.

  1. Insert Volume Shaper (VS1) on the master, purely as a wavefrom display set to 1/4
  2. Create a synth track and have it play a very low sine wave, a sub
  3. Insert a Volume Shaper (VS2) on the synth track, draw in a hard duck, instant start, 100%
  4. View the VS1 on the master, all as expected
  5. Insert Frequency, after VS2, apply a low cut 96 at 30hz
  6. View VS1 on the master, we now have a tiny bit of sub at the start

At first i though it might be Volume Shaper (the one ducking the sub) not lining up correctly (plugin compensation?) so i tested by automating the Sub synths volume fader (which was a lot easier to do now thanks to curves), same issue. I also tested by the old compressor side chain method, same issue.

So we know Lowcuts shift the phase, is that all is at play here? How do we work around it? Switching frequency to Linear mode removes most but we still get a tiny, tiny bit. For the past few weeks I’d rested my mind that this was the issue but today i came to notice Ozone 8 Vintage Tape introduces the same problem.

Why this is huge! I’ve seen many swear by low cutting the master, pre slam, yet if we observe this visually, we can see how destructive it is to the transient of the kick. If I’ve set up a perfectly super tight Sidechain or Shaper so that the kick sample sits perfectly as it is, unchanged every time, simply applying the low cut, adding Vintage Tape, some other plugins on the master, will result in the low end shifting, escaping the duck and seriously exciting the transient of your kick.

2

Are you looking or listening? Also volume shaper is not a steinberg plugin, maybe ask cable guys?
When listening, room acoustics also come into play.

I also don’t understand what you mean with “master” ? you mean your 2-bus? that should only affect the total sum, the 2-bus can no longer shift individual signals. It might be something as simple as a “visual rounding” thing. meaning that the combined signal, forces to quantize some values and that’s why either one shifts one or two samples on your display. I would be more worried about how it sounds than about how it looks.

3

What’s the audio buffer size when you’re observing this?

4

Master = Stereo out… I tried it with other plugins, same issue. I had put it down to some sort of visual rounding on 1 day, as i did for the LC on the channel EQ, which actually boosts low frequencies (i’ll save that for another thread) but it turned out that the displays are correct, it was a trait of Cubase channel EQ.

I would be more worried about how it sounds than about how it looks.

As for this… NO! I want to fully understand what is happening when i apply different things, this way i can better implement them. I’m more into how things work than making actual songs. If doing as I did shifts the low end, i want to know that it shifts it, this way i can account for it. It might actually be desirable but I want to know!

Thank you.

5

I never thought about that. 512. Changing this might help me rule out if it’s something up with delay compensation, resulting in the plugins ending up out of time. If it stays the same, it’s likely more to do with the properties of how sound actually works.

When we EQ the low end, the phase is shifted but i didn’t expect the timing to shift, not to this extreme.

Thank you.

6

Changing buffer settings makes no difference. To rule out visual rounding or VS being at issue, I rendered the audio.

As we can see it’s not only do we get a shift, it increases the wave length of each cycle ever so slightly (changing the pitch). Linear doesn’t effect the WL but it’s not true linear as there’s still a slight shift. It must be an attribute of sound as i mentioned above. When pushing for max volume, this is huge, that little bit of sine exciting the transient of kick is seriously going to alter the dynamics of it. Put more into the limiter! remember the full frequency range doesn’t shift, it’s relative to what we’re doing.

When you view it in action it makes a lot more sense.

We spend ages fine tuning the sub and kick to not clash, only for something like this to shift it. Looks like I’ve got a fun day ahead, testing different plugins.

7

how many samples are we talking about? at what sample rate? and what’s the volume? you won’t hear 1 sample at -50dB. also did you see that it’s basically the transient being swapped from end to start? please provide a screenshot with 1 sample selected (smallest selection you can make) to put things into perspective

8

In the picture I’ve supplied, the gap is the pocket of where a kick would sit, the standard length of a duk, one can see it’s a considerable shift.
Sample rate is 441.
The volume is irrelevant. The louder it is the louder the part is that should be ducked, that isn’t ducked.
The transient isn’t being swapped from the end to the start. It could be the transient of the next note but in this instance, it’s 1 pure tone being ducked.

9

A video of it in action with the kick would be better but these 2 picture show the difference.
No Cut

With Cut

Using Volume Shaper on the 1/4 view is a really good visual tool. It loops round stationary, unlike Ozone, which scrolls. When the kick sits in the pocket, it’s easier to see the kick staying true to itself. We can clearly see how much of the sub is interacting with the tail. Now we can trim release times and the tail to be sample perfect… However, it was noticing the transient of the kick behaving erratically, changing with each instance of itself that led me to stumble up on this. Sure enough, mute the kick and we can see that some plugins will shift the alignment of the bottom end. That little bit of sine wave, visible at the start.