Cubase Noise on Export Audio / Noise floor Issues

Update to Original post:
Thanks to input form other users, there is an issue with Cubase and 3rd party plugins adding noise that can be replicated by others.

Check below for some video and further descriptions of the issue.

Anyone else having this issue or can repicate it. Its not something that is instantly noticeable, so it can be happening to you without you knowing :wink: Have a check,

viewtopic.php?f=250&t=134316&p=728526#p728526


I’m having an issue where I see that a buzzing sound which is panned completely left is being added to Export - Audio Mixdowns in Cubase 9.

It happens only with certain plugins - eg Decapitor by Soundtoys. I understand this plugin generates “noise”, even when nothing is playing, and I can actually see this monitoring the channel using Voxengo Span.

BUT the buzz I get on Export is not the same. Its down about-135db, which though that is low, if I have a few of these, and some quiet tracks, its getting noticeable that get increased in volume when the final song is done. Critically, this “buzz” is not happening during play back prior to Export, but only in the exported audio wave.

Why do I get this buzz added - is it something to do with the Export function, or the plugin, and why is it panned hard left? Surely its not normal?

Has anyone else any experience of this or can replicate it? Try just one track in Cubase, a soft synth anything eg Zebra or Retrologue, and add Decapitator or any saturation/distortion plugin like Fab Filter Saturn or similar. Do you get the same thing happening? Note: it happens at quite quiet levels so in Span settings I’ve been putting the Range Lo right down to -180 to see it graphically, but even at default setting you can see it in numerical format on the Peak readings.

Do you export Realtime or non-realtime ?

I’ve tried both, with same result.

Tested with Retrologue + Blue Cat Destructor or Steinberg Quadrafuzz. No buzz at all here.

What are your settings when you do the export (screenshot please)? Which section of the resulting audio file has the buzz ?

Can’t test directly as I do not have that plugin. But I think it extremely unlikely there is any kind of bug with the export function. IMO Export works flawlessly.

I think you may have already partly answered your own question. If you don’t use that plugin when you export then presumably you don’t get the buzz ?.. therefore it’s not the Export function… it’s the plugin or some other variable in the way you are doing things.

I attach a screenshot here. It shows both the Audio mixdown settings and the Span showing the artifact added.

I understand what you mean by it must be the plugin which is introducing the artifact BUT- I just did a test on an old version of Sonar with exact same setup, and I get no artifacts at all, just a clean recording. So, its definitely something to do with Cubase that is causing this.

Attachment of image here

The export settings look fine.

What happens if you do the same test but use Quadrafuzz instead of Decapitator? My guess is that you will get zero noise with Quadrafuzz.

I re-tested here using a similar set up and did an analysis with Span. I also did a full analysis of the resulting file in Wavelab. No buzz, no noise.

My guess is that the noise is entirely due to the Decapitator plugin (and some other variable is at play in your Sonar test, such as bit rate / sample resolution… did you export at 24-bit?).

In my opinion, the noise may be an intentional side effect of this plugin since it’s designed to reproduce the noise and characteristics and vibe of analogue gear. Its whole purpose is to NOT be clean. So they may have designed the plugin to be active at all times, even on silent passages of audio? I’d suggest you write to Soundtoys to find out. One other way to find out is to ask the following question: ‘Do the characteristics of the noise interference change according to the settings of Decapitator (for example, what happens if you engage or disengage the ‘Punish’ button)’? and then test it. If the noise changes according to the settings, then you probably have your answer. All guesswork since I don’t have Decapitator.

Apart from this I don’t have much else to say since I can’t test Decapitator. Perhaps someone else here who has the same plugin can test it.

Thanks for the input.

With Quadrafuzz it worked ok.

Some of these plugins DO send out noise when idle, and that is expected, BUT … it is not the noise that is sent out that is the issue – during playback I can see the noise the plugin adds, but when EXPORTED this additional left hand side buzz is ADDED at the export stage.

And also as I mentioned, in a test with Sonar with the same plugin, there was no issue at all.

If anyone with Fab Filter Saturn or Decapitator could reproduce this? Or, is there any other setting within Cubase which might possible affect it?

IMO that means that the problem lies with Decapitator. Does it not?

IMO almost certainly a plugin issue. Did you contact Soundtoys?

What works in an old version of Sonar does not prove that there is no issue with the plugin. And by the same token it doesn’t prove that there is a problem with Cubase. Did you export at 24-bit in Sonar?

I’d also suggest the following (as mentioned above):
‘Do the characteristics of the noise interference change according to the settings of Decapitator (for example, what happens if you engage or disengage the ‘Punish’ button)’? and then test it. If the noise changes according to the settings, then you probably have your answer.

The issue seems to be how Cubase handles Decapitator, for whatever reason. Since it worked in Sonar (and I did an EXACT same set up in Sonar as I did in Cubase), that proves it. Its not just Decapitator. Its Fab Filter Saturn, its Neutron Exciter, and Ozone. It can’t be all those plugins are bad. Something seems to be happening, that Cubase is adding something, during the Export (since it doesn’t happen on play back), and only with certain plugins.

Did you export at 24-bit?

Yes, 24 bit.

To do a further test, I downloaded a demo version of Studio One, and did the exact same set up and recording. The exported audio was like Sonar, without any of the strange artifact. So, I think that is conclusive that its something within Cubase that is causing it. I’m not knocking Cubase here, I really wan to find the solution. There must be a reason why its happening in Cubase but not in Sonar or Studio One.

Without the plugins I can’t offer anything further. I do hope you get it sorted and I wish you luck with it!

You’re using Cubase 9. Have you tried the Cubase 9.5 trial? Maybe enabling the new 64 bit processing mode could make a difference. Note that you have to restart Cubase after enabling the 64 bit mode for it to apply.

Enabling 64 bit processing has been shown to completely eliminate the noise caused by a few plugins.

Thanks for the tip - I havn’t updated my signature but I am actually using 9.5, and I tested this in both 32 bit and 64 bit processing, same result.

Decapitator shouldn’t add noise to silence - some other SoundToys plugins such as Radiator and Little Radiator do add a background hiss unless you turn it off. I would hazard it’s a bug. In your preferences do you have disable plugins when no audio is present ticked?

(edit) PS have you tried fading your audio track in? There might be an inter-sample glitch causing a burst of noise which decapitator is then adding (intended) harmonics to.

Thanks

In Preferences I have something called “Suspend VST 3 plug-in processing when no audio signals are received” - did you mean that one?

Fading the audio in sounded like a good idea … I tried it. When instrument level was 0, the glitchy artifact was zero, but after the volume had risen a little, about -28db on the volume fader, it came on, same -135db level and stayed on same level as the volume fader increased.

Can you try turning off Multi processing in Studio Setup/VST Audio System? And repeat the test?