Please ensure Javascript is enabled for purposes of website accessibility Jump to content

Long running reverbs/delays cuts off abruptly


mikaelhansson
 Share

Recommended Posts

Seems like they cut off after about 10 sec. Does anyone else experience this?

To reproduce, just take one of the longer reverbs, like the new Ganymede, set decay to max, send a short sound through it and wait. Same problem with delays, just bump up the feedback with something like the Transistor Tape.

Btw, this problem was also present in the previous version.

Link to comment
Share on other sites

Just to start off with the basics.  Have you tried closing out all other non-essential applications and/or rebooting your PC/Mac?  This will free up RAM and CPU resources necessary for the Helix Native DSP to work efficiently.  Speaking of DSP, are you approaching the Helix Native DSP limit, or are you just experiencing this on the new reverbs only?

I would try it with nothing else in the signal chain to see if you have the same issue.  If you don't, that may point to a system resource issue.

Link to comment
Share on other sites

I wouldn't say resources are a problem since I've been running 16 simultaneous instances of Native as a test before, I'm on a Late 2016 MBP with 16GB.

Just using an empty project in Cubase, playing a piano through one instance of Native, CPU-meter hardly reacting. Also tried with the Legacy Digital Delay, same problem.

I'd guess they just cut processing off after the input has been inactive for something like 10 sec. Mostly not a problem but not so good for esoteric, ambient use of the reverbs and delays.

Link to comment
Share on other sites

Ok, so not a universal problem. Downloaded Reaper to try it in another host and both the AU and VST3 versions works there so it's either a problem with Native in Cubase for Mac or something in my setup. EDIT: I should add that other plugins don't have this problem in my setup.

Anyone else with Cubase 9+ on a Mac that can try it out?

Link to comment
Share on other sites

No, it's definitely time based as the time until it cuts off is unaffected by the current level of the reverb tail or, if I'm using a delay with endless feedback, the signal is actually hotter when it's cut off. No other plugins have this problem. I've tried both built in and 3rd party plugins.

Mysterious indeed...

Link to comment
Share on other sites

Ok, I've found the reason. In Preferences->VST->Plug-ins there's a checkbox for Suspend VST 3 plug-in processing when no audio signals are received.

Still, other plugins seems to handle this even if the checkbox is ticked, I guess they are checking if the plugin is still outputting sound and somehow "tricks" the VST3 protocol.

I would say that this (like the other plugins handle it) is the preferred solution as having it unchecked drains unnecessary resources from plugins only used in other sections of a track.

Link to comment
Share on other sites

If anyone from Line 6 is snooping in there's some info in the VST3 SDK that might regard this:

IAudioProcessor Class

virtual uint32 getTailSamples( )

Gets tail size in samples.

For example, if the Plug-in is a Reverb Plug-in and it knows that the maximum length of the Reverb is 2sec, then it has to return in getTailSamples() (in VST2 it was getGetTailSize ()): 2*sampleRate. This information could be used by host for offline processing, process optimization and downmix (avoiding signal cut (clicks)). It should return:

  • kNoTail when no tail
  • x * sampleRate when x Sec tail.
  • kInfiniteTail when infinite tail.
Link to comment
Share on other sites

No difference if Trails is on or off.

I have dived in to the VST3 specs to get some insight into this. All audio processing plug-ins have to implement an interface called IAudioProcessor. In there is a method called getTailSamples that are supposed to return the number of samples that are needed to let the tail decay. The VST3-host can then use this information for whatever it wants. Cubase use it to reduce cpu load by asking the plug-in how long the tail is and then disables the plug-in if there's no audio input and the tail has decayed. This resource saving function can be disabled by unchecking a checkbox in preferences, hence why it works when I uncheck the setting...but at the cost of all plugins staying active, regardless if they are only used for a single bar in the beginning of the song. Reaper don't have this feature what I can see, all plug-ins stay active, that's why it works there.

I also downloaded Steinbergs TestVST-host. It contains some conformance tests and, surprise, it failed in the "Check tail processing" test. :-)

As this only applies to VST3, it fails in Cubase but works in Logic (AU plug-in version). All this makes me fairly sure this is a genuine bug, it would be really odd with a problem in my setup that only affects Native and not other plug-ins.

I submitted a ticket but I'm having a hard time getting past 1st line support, I've had to answer twice that unchecking the checkbox is not an acceptable solution.

  • Upvote 1
Link to comment
Share on other sites

  • 2 weeks later...

As an update, this was reproduced and confirmed by Line6 so it was added to their look-into-it-list.

I offered some ideas about solutions but just got a response to add it to Ideascale which seems odd after looking into what's normally posted there.

I'll just put it here in case someone is interested:

Hi, thanks for the reply! Yes, I realise it's quite complex. If I'm not getting this completely wrong, I guess an approximation could be done by having each module report its decay time and then just add them together left-to-right, applying a max function where there are parallel paths. If the problem is deemed too complex, I would suggest that you make a (user)setting per program where you can make the plug-in report an infinite tail. This way you can let the plug-in stay active only when it's needed without having to disable Cubase's resource saving feature.

  • Upvote 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...