Automation Timing Is A Little Off.

This is hard to put into words but I’ll try my best. I’m using automation nodes (the little dots) on the automation window. I believe that when the node “hits”, the parameter changes a few milliseconds after it hits, and not at the same time. I just did an experminet with a 303-style VST synth. I placed a note on every bar (every fourth line), then went to the automation window and placed a node right at the top (maximum cutoff) on some note then another node right at the bottom of the window (min cutoff) on another note. I found that when it “hits” the node, there is a slight “ramping” of the cutoff to it’s new value, it isn’t an immediate change. This is causing me problems in a track I’m currently working on as I’m trying to have a kickdrum that changes a certian value on the VST on some of the notes. If I put a node on the automation window to tweak the kick, then return it to it’s original setting, both the tweaked kick and the next one sound different. I’m sorry, this probably doesn’t make any sense. To put it simply there is some inertia on the automation window. I’ll try my best to clarify is this doesn’t make sense.

I understand what you mean.

Are you certain that it’s Renoise and not the VST itself? It’s quite common for filters in VSTs to have a response/inertia setting (which Renoise’s built in Filter2 has) because if you change the cutoff of a filter instantly by a large amount it generally creates pretty nasty sounding glitches in the output. So the change between cutoff amounts needs to be interpolated or smoothed out to some degree, which sounds like the ramping effect you’re experiencing.

Also, which mode are you using in the automation? I believe “points” mode is designed to change the parameters instantly without any smoothing/ramping by Renoise, while the “linear” and “cubic” modes will interpolate between points.


In my experience cubic and linear mode still do not interpolate between the points. Hence the thread I started in the suggestions section. Still not had a chance to save files and upload to demonstrate though…

It’s not the VST. I’ve checked thier settings and they don’t have a configurable inertia. It’s not possible to do sudden changes with spline or interpolation either as you can’t have a 90 degree vertical slope on the graph. (even if you could it would be irritating to do that way.) I used to do sudden changes of settings on Buzz tracker all the time and I never noticed any glitches or pops. If you are doing filter cutoff sweeps on a synth then the slight ramping would not be noticeable but it cannot do precise and sudden changes of parameters without sounding a bit dodgy. I need it becuase I use these changes right on a beat (start of note) and if there is some slight attack and decay to the change, the effect I am trying to make doesn’t work.

Here’s a quick automation test I did using the 3 play modes. It’s just a sinewave with it’s volume automated back and forth between 0% and 100%. The same automation envelope is rendered in points mode, linear mode and cubic mode respectively. There is no perceivable difference between linear and cubic in this particular test, but the difference between points and linear/cubic is very obvious.…omationtest.wav…omationtest.mp3

Points mode, although much “faster”, does appear to still have interpolation, which makes sense because the results without interpolation would be hideous. Though I can see how if you want absolutely instant “snappy” results from the changes, even this small amount of interpolation could be a big problem. Perhaps a future version of Renoise can include another automation mode - an “absolute” or “instant” mode - which uses absolutely no interpolation.

If it’s at all possible in the way you have your track setup (ie. without creating an unwanted sound), perhaps you can try automating your filter change one point before you actually need it to occur. The cutoff should then be where you want it right as your note hits, but obviously you might get a bit of crossover from the previous note which may or may not be avoidable using this method.


Here’s another quick test I just did to demonstrate the filter problem. The cutoff frequency of a lowpass filter is automated to random values, and there is absolutely no interpolation being done when changing from one value to the next. You can clearly hear the glitches/clicking sounds.

As far as I can tell there is always some level of interpolation occuring on things like this, it’s just a question of how fast it works. If it goes too fast you get glitches, if it goes too slow it might not be responsive enough for the user.

Hmmz, i’ve also reported some similar behaviour upon the pitch envelopes in the instrument envelop editor:

I just tried to do sudden cutoff changes on Buzz tracker and it does the same thing.

I just tried it with my windows drivers and it seems to be OK now, no ramping between values. Previuosly I was using ASIO for all.