Audio routing issues with Cubase 14 and Mac Studio

[damien6]

System: M3 Mac Studio Ultra
Sequoia 15.4.1 (24E263)
Presonus Audiobox 1818 VSL and Focusrite Scarlett 18i20 Gen 4

I have not been able to successfully reproduce how my Cubase sessions get into this state, but I am running into major issues with what appears to be audio routing into third party plugins that support audio sidechain.

Issue: The way I’ve encountered this bug is by having an instance of Slate Digital’s Virtual Mix rack with a custom preset that includes a compressor with sidechain functionality on a track. Randomly it will appear that a pre-effect VST gain staging setting will get maxed out or the audio going into the plugin is doubled. The volume meter on the module (like the 1176 clone) will shoot to the max volume indicating a very loud signal is being received and the audio will completely cut out. Sometimes it fades out, then if I disable the module, the sound will fade back in. The input on the module is not driving lots of volume, this occurs even if the input is at its absolute minimum on the compressor module

If I hit the “Arm to Record” on the track, it will work and the audio is fine, but as soon as I click off, the sound fades out and the volume meter on the VST shoots back up to max volume. I tried testing with a Plugin Alliance channel Strip (the Lindell 80) and it is showing the same behavior. The audio signal will either cut out or become very loud and distorted as if it’s either doubled or the gain has been maxed out and the incoming volume meter will shot to +12db incoming signal or more (2x or louder than my stereo track volume).

If I disable the plugin or sidechain supporting module in Virtual Mix Rack, the audio is perfectly fine. For instance in VMR, I can run the EQ modules and never have any issues, but the compressor modules that support sidechain all have this issue.

I have found that if I drop an instance of Virtual Mix Rack with the default preset in the insert chain before the problematic effect plugin, that seems to fix the audio signal and I can remove it and hear the audio through VMR or other plugins. However, this morning, despite being able to hear the track in the session itself and thinking the issue was not occuring, when I export to MP3 to pass along to a friend, the Group Tracks I had VMR on both failed to produce audio in the mixdown track.

I do not have any sidechain signal feeding these tracks from within Cubase or anywhere else, no audio should be coming into the sidechain signal at all.

Possibly related, I have noticed a few times where tracks will somehow route themselves to FX sends even though they were never assigned. They seem to randomly assign themselves to the send track and disable themselves (turn grey). I try to clear the send and it will not clear, it just sits there, in the grey/disabled status.

Eventually all of these issues will cause Cubase to crash.

I first thought it could be my interface since mine was old and discontinued, so I grabbed a Focusrite Scarlett 4th Gen and am still having the same issues.

I’ve done deep dives into my audio routing and cannot find anything wrong. My setup is extremely basic, I am running a stereo out track that is not connected to my sound card (“No Connection”). I am running Control Room with two monitors, one outputs to my studio monitors, the other to my headphone channels. This mirrors the setup I used in Windows for years with no issues.

I’ve also done multiple fresh installs of Cubase but continue encountering this issue.

I upgraded my license to Ableton Live and tested VMR and other plugins there and do not have the issue. I’ve also reported this to Slate Digital and they think it’s on Cubase’s side.

All of this is rendering Cubase unusable for me. I’m really hopeful for a solution because I don’t want to stop using it, but this completely renders the software useless.

Here are my most recent crash reports.
Cubase 14-2025-05-03-165335.ips (532.0 KB)
Cubase 14-2025-05-07-081548.ips (661.2 KB)
Cubase 14-2025-05-07-081841.ips (650.1 KB)

[ATC]

Unfortunately you’re dealing with the effects of two software playing together and each company probably will say to contact the other… on top of that it sounds like you’re dealing with a couple of issues at once 1. Audio Routing 2. Side-chain glitch 3. FX send unusual behaviour 4. Export issues

To save me reading your post again, did you manage to resolve any of those?

How do you try to clear the FX send? Select “no effect” at the top of the list?

Are you using any kind of template or a blank project?

Does using just one interface change anything? (I use an 18i20 to without issue fwiw) Are you using an aggregate device ?

Can you solo/export audio from the group track by itself?

Some of the audio sudden boosts and fade out behaviour you mention sounds almost like there’s feedback or a loop somewhere

[damien6]

Thank you for responding.

I have tried removing the FX send, but I think I figured out why they were randomly appearing - For some reason the option was checked to add sends to every new track in the Settings → VST area. That should clear up that and eliminates one possibility of why this audio routing issue is happening.

To answer the rest of the questions:

Are you using any kind of template or a blank project?

No, this is using a completely blank project. What’s really wild is when the issue is happening, it will continue to happen on a completely blank project. If I resolve it on that new, blank project, it will “fix” on my other projects as well, so it definitely seems like there is something in Cubase’s settings that is being affected by this bug.

Does using just one interface change anything? (I use an 18i20 to without issue fwiw) Are you using an aggregate device ?

So I am only using one interface at a time. When I grabbed this Focusrite, I pulled the Presonus Audiobox out of the rack completely since it’s old and discontinued and has not received an update in a long time (I think the last update came before the M chips, which was why I was hopeful a newer, supported interface would be the solution).

Can you solo/export audio from the group track by itself?

Yeah, I’ve tried soloing the group track with just the instrument/sampler track/etc… that feeds into the Group track. Still has the same issue, and if I export, the sound is still affected by this bug. I’ve also tried activating and deactivating the plugins, which coincidentally caused yet another crash almost immediately last night.

Cubase 14-2025-05-07-181830.ips (1016 Bytes)

Some of the audio sudden boosts and fade out behaviour you mention sounds almost like there’s feedback or a loop somewhere

Potentially, the onset of the sudden volume increase is pretty sudden. When I hit play on the track, the volume meter immediately shoots to max and there is something going on. Thinking about it, one argument for it being a feedback loop is that when I’ve tried altering audio signal paths, I can sometimes hear a bit of the audio sneak through the chain, potentially as the audio signal is disrupted and the feedback loop builds back up.

So I think 3 of the 4 issues are related, potentially also impacted by the 4th, but I’m just at a loss for how to proceed since at this point it doesn’t seem to be anything solvable through the UI.

1. Audio Routing (only affects instruments with sidechain, so affects #2)
2. Side-chain glitch (seems to be how the audio routing is getting received causing the bug)
3. FX send unusual behaviour (I think this was just the setting I didn’t know was enabled)
4. Export issues (Seems to also be affected by issues 1 and 2, but is also still showing the same behavior even if listening to the track with the plugins on it appear to be okay when just listening in the Cubase session).

I hope someone takes this issue up and can find a solution - I love Cubase and don’t want to go back to Ableton or look for yet another DAW, but I also

[ATC]

I don’t know if re-installing Cubase wipes preferences, but it seems unusual that a fresh install would have “Connect Sends Automatically for Each Newly Created Channel” selected as default. You could also try getting into the settings and resetting everything to default? Down the bottom left of the Settings you can choose the “Preference Presets”

I would definitely look into the feedback as a potential issue. I’m not sure of the timeline of all of this, but the 18i20 has a “loopback” function you might want to investigate if you haven’t already, that could be one potential cause, otherwise if it was prior to the 18i20 (which it sounds like it is) you should go through your routing with a fine-tooth comb, post screenshots of your Audio Connections and Studio Setup if you still get stuck (I wouldn’t know what to do with the crash report .ips files sorry…) You could set up a couple quick test projects with clear/easy routing for testing?

Next time you export, take a look at the checklist of tracks on the left side of the Audio Mixdown dialogue box that opens, check settings there in general, see if anything is unusual.

I don’t have any definitive answers but hopefully some of those ideas help.

[damien6]

Yeah, thank you - I’m not sure why or how that preference was enabled. I might have done it by accident. I don’t think I would have enabled it by default. I did go through and manually delete the preferences files when I’ve done the clean install of Cubase per their instructions.

And sadly when this issue has occurred I’ve started a brand new empty session (no templates, use the “New Empty” option), put one single instrument track on the project then loaded VMR, trashed the default preset and dropped a fresh new 1176 into that first slot and the problem is there. It’s so bizarre.

I’ll look at the Loopback function on the Scarlett to see if I have that channel routed to anything. maybe with a little luck I did fix the weird configuration and that’s what’s causing the problem now. But it definitely started when I had my old Presonus interface and carried over to the new Focusrite.

I glanced at the export settings when sending the file to MP3 and it all looked okay - just exporting a single track from the stereo out channel, but yeah, something is definitely going on there because it was killing the audio on those tracks.

Thanks for your responses. I appreciate your attention on this and your thoughts on things to look into. I’ve probably spent 20 hours troubleshooting, digging into stuff, I even saved out a test track and opened the Cubase Project file in a notepad editor to see if I could see any data points in there related to the problematic plugin, but haven’t been able to find much. Also, if you do open a Cubase project in a text editor, it will make it so the project can’t open in Cubase any more, so make sure you only do it on a backup project if you decide to.

[damien6]

I uploaded video of the behavior here for reference (it doesn’t have audio - I’m using the default Mac screenshot recording software and I don’t know how to capture audio and video with that):

You can see on the spectralayers meter, when the track’s not armed, the output drops to zero but the volume meter on the compressor shoots to max. When I arm it for recording, the Volume Meter drops to where I would expect it to be and the spectralayers meter indicates that audio is being sent again.

Cubase Audio Routing Issue

I also started a reddit thread to see if there is any hope of a resolution there: Reddit - The heart of the internet?

[damien6]

Audio examples of the issue that I’m seeing in the export (but also what I hear in the session when this is problematic. Also video of the crash I had when I was trying to export these tracks (this is pretty typical of my Cubase experience right now).

VMR Disabled: https://drive.google.com/file/d/1O7FJfQp9lmRLSlzDtBjwjDDH5YJqo-0d/view?usp=drive_link

VMR Enabled: https://drive.google.com/file/d/1747sxpQgdo-6T6fk47BKnck7lXRTTcbN/view?usp=drive_link

Crash video:

Crash while Exporting

Crash log:
Cubase 14-2025-05-09-134501.ips (648.4 KB)

[ATC]

That crash is strange… Is your Audio Performance Meter showing anything unusual (right click at the top and tick the box to show it) or the Activity Monitor app on your Mac? I assume all your software is legit? Does it crash with VMR not used?

As for VMR/the track, it looks like you have Preferences > VST > Auto Monitoring set to something other than “Manual”, which (unless you’ve specifically changed that yourself) could indicate that there are still certain settings in your preferences that aren’t default (at least while troubleshooting this).

I’m not familiar with Slate plugins personally so I don’t know what to say there, or how your sidechaining is set up, so again I can only suggest to triple check all routing both in Cubase and VMR. You could also try sidechaining in the stock Cubase compressor if that helps to test, if you get some sound coming through as intended.

How are you disabling VMR, with the bypass button, or just turning off the rack elements in the plugin? Again I’m not sure when it comes to VMR how it should behave.

Also I’m not sure if there is meant to be sound at certain points in your video screenshot or if the video is without sound.

[damien6]

I tried a few more tests with the same results:

• I installed Cubase 13 and had the same issues as Cubase 14.
• I disconnected my Focusrite and tried using the Mac’s built in audio and also had the same issues.

Both of these showed the same results, so I’m starting to think there is something fundamentally flawed with how Cubase is processing audio and functioning in the new M3 Ultra chips. I don’t know for sure, but I’ve eliminated and tested everything I can. I’m out of ideas for the time being.

Oddly enough, I’ve also tested some other plugins and channel strips and have varied results:

• Process: I loaded a fresh, “Empty” Cubase project. Loaded up an instance of Xfer Serum with the default patch.
  Plugins Tested:
• Arturia Pre73 and TridA (the 76 emulation doesn’t have a volume meter to confirm) - same issue - extremely hot signal coming into the plugin
• Plugin Alliance’s Lindell 69 and 50 series seemed to be okay, but the 80 series continues to show an extremely hot signal coming into the plugin:
  
  
  
  Here is the volume level using just the bus channel plugin:
  
  

Oddly enough, you can see the hot signal coming through even with the track armed (the sound being produced isn’t distorted as it is when I unarm the track with the Lindell 80 on the track), but the actual audio being produced isn’t distorted like the track is being over driven by an extremely hot incoming signal.

In my testing I also found that at some point it seemed to be working, so I was playing this section of a track when the channel suddenly went silent because the issue cropped up. Just listening to a section of the track when the audio just vanished suddenly at which point I confirmed the issue was present.

At this point unless I can think of anything else I don’t plan to do much more testing. There is something fundamentally broken that I can’t resolve or identify.

[damien6]

Hi ATC, thanks again for looking at this. I was actually typing up more troubleshooting when you responded.

Audio Performance from what I’ve seen is fine - no spikes or anything. This has happened on a project with one track and one instance of serum with a plugin on the track, so super minimal setup. I seems more like the audio signal over driving Cubase so much that it can’t handle it any more and it crashes.

All my software is legit and up to date (I barely set up this new computer and installed everything within the week prior to finally sitting down to use Cubase for the first time), I don’t used any cracked versions of anything.

The Auto Monitoring is set to Manual:

On a recent crash I used the “Delete all preferences” just to try resetting everything and still had the same issue.

For the sidechaining and routing - this is happening even if I have no sidechain setup at all. I don’t even have the sidechain channel enabled, so it’s really bizarre (if that is the cause, just my speculation right now) that it’s getting anything on that channel.

With VMR, you can enable or disable the individual modules within the plugin, and I’ve seen the same behavior with all of the options:

• Disabling/Deactivating the entire plugin - everything sounds okay, exports okay (though this usually leads to a crash deactivating and reactivating the plugin)
• Removing the compressor module from within the plugin’s channel strip
• Disabling and re-enabling the compressor / module with sidechain from the strip while leaving the plugin itself enabled, including leaving other modules enabled that don’t support sidechaining, like EQ’s (disable it, it works fine, enable it, problem is back)

Sorry, there isn’t meant to be sound - I am just using the Mac’s screenshot software and it either doesn’t record sound or I don’t know how to set it up to do so. I’ve been a Windows user my whole life - this is my first Mac so I’m learning a lot here haha.

[ATC]

Without seeing your device/setup in the flesh, I’m not sure I can suggest much more - I hope you can find a solution.

I saw a few threads in other forums about Slate plugins crashing DAWs and internet connections causing issues (but that might be an old problem, in the days of iLok etc.), I’m sure you’ve used some google-fu to find clues.

I’m on a 3rd gen 18i20 and M2 Max 64gb, using waves and native instruments among others, I rarely experience crashes, can’t remember the last time. Beyond your issues, if you remove all 3rd party plugins and audio interfaces, and Cubase is still crashing or acting weird, that’s definitely something I hope the Steinberg folks help you with. Even with the plugins I hope you hear back.

Wildcard suggestions, you could try running Cubase in Rosetta mode, see if being online/offline changes anything (for the plugins you use, although I really don’t expect that to change anything), if you have another device trying running Cubase on that.

Good luck!

[damien6]

Thank you, I am to the point that I suspect there might be something going on with the architecture of the M3 Ultra chip or something at this point.

Thanks again for helping provide some thoughts on this one. I’m stumped, too - I’ve tried everything I can in the UI and everything else I can do myself, so I’m not sure if there’s anything anyone but Steinberg can do at this point. Hopefully they decide to help look into it, but sadly it’s been a few days and this issue keeps sliding further down the list without a response from them, so I’m feeling pretty sad and defeated. I’ll keep an eye out for possible solutions but in the meantime, I’m going to Ableton.

I do appreciate the attention and your thoughts on the matter, though.