VST overheadroom (solved)

Hi community,

I have a question probably sounding strange: can anybody tell the headroom in the digital domain concerning:

  • cantabile (inside)
  • vst plugs in general?

Story behind: I‘m just doing some tests with ik multimedia leslie. Surprisingly I tend to get this heavy distorted organ sound many keyboarders are seeking by increasing the input level dramatically (means: the level meter of vb3 nearly standing still at maximum level.

Now I‘m not really clear what is happening: is there an internal limitation due to the limitation of vst (or internal cantabile limiter?) producing additional harmonics or is the overall process still linear (meaning the amp simulation inside leslie is doing a good job) and only the level meter isn‘t able to resolve the overhead produced?

Thanks in advance, humphrey

You say ‘input level’, so I assume you are driving the input to the Leslie plugin very hard?
In a 32 bit float environment (I’m guessing that’s what Cantabile is) it’s my understanding that you can generally go crazy with gain inside the software. As long as you don’t crunch the outputs to the real world you’re OK.
If it sounds good to you, why not?
The Cantabile limiter only operates on the physical output channels, AFAIK, and that’s the only place you would want it, if at all.


The Leslie is an amp sim- it’s designed to do what an amp would do, i.e. overdrive at higher input levels. If it sounds good, then it’s probably by design. I imagine it also has its own internal limiter at the output stage to prevent hard clipping. Of course digital levels are a brickwall and if you go into real clipping at either the input or output you will encounter Bad Things and the sound will reflect that. If you aren’t clipping on the input and the plug is designed properly you shouldn’t be able to make it clip improperly inside the plug itself, although you can always set the output too high and clip there (which is why all the limiters are in place even tough they aren’t infallible).

1 Like

32 bit float discussed here:


First off: thanks alot @FredProgGH @Ade for replying. This helped to get clear I have to be more precise when mentioning a question so here some aspects to clearify what I mean:

I agree that cantabile is most probably working in 32bit floating point audio (and I‘m aware there is the possibility to go the 64 bit route)

I‘m aware that 32 bit floating point gives me a dynamic range of far more than 1000dB - so more than enough room for increasing levels to any value I like, but: this only works if a part of the dynamic range is placed above the zero dB mark of the DAW. Matching 0dB to 0dBFS would even in 64 bit floating point mean that there is no headroom available and this simply is the information I‘m missing. Even if I leave away the leslie plugin I‘d be interested in this.

While reading and discussing things an idea came to my mind to find out if clipping occours above 0dB: simply routing a test signal to a linear amp plugin followed by an attenuator making an overall gain of zero dB should answer the question very quickly.

Finally I agree: „If it sounds good simply take it“. Maybe I should simply trust my ears.:wink:

Kind regards, humphrey

Edit: just gave it a try with 40dB gain followed by 40dBs attenuation without noticable clipping


This is interesting… I know with, say, Guitar Rig you’d never get away with that. The input level would clip badly. Now I want to play around with some things :wink:

Good luck! :wink:
Regards, humphrey