M9 Docs   Questions & Answers

What's the difference between a 'sequence' and a 'sequence clip' ?

A sequence is a sequence of events. It can also define a loop.

A sequence clip is a composition clip that plays a sequence from a certain position until a certain position, and also defines where the events should go to, i.e. it defines a target module.
A sequence clip is not a sequence, it uses a sequence.

Saving a sequence preset will result in a MuSequence file.
Saving a sequence clip preset will result in a MuClip file.

What to do if there was a crash while saving a project?

When saving a MuProject file, MuLab always first renames the original project file to ProjectName.backup
If MuLab crashes during writing ProjectName.MuProject file, then the ProjectName.MuProject file will most propably be unusable.
But you can still recover the previous saved version from ProjectName.backup.
Of course this should be done with care, eventually with an extra backup done by you, so that you will not loose this precious backup when the unusable ProjectName.MuProject file is renamed to ProjectName.backup the next time you save ProjectName.

Sometimes i'm having trouble using certain files. How come?

Note that MuLab does not like special characters in file or folder names.
Here is the complete list of the non supported characters in file or folder paths:  /  \  *  ?  :  "  <  >  |  ^  
The reason is that these are characters with special meanings on Windows / MacOS.
The point is only supported as a separator for the file name extension.

Windows: A crash occurred. Where can i find the crash technical details?

To find the crash details there are 2 cases:

1) If you see a MuTools red alert box from MuLab, then the crash details should be in the MuLab log file.

2) If you don't see a red alert box from MuLab (but rather a Windows alert box) then you can find the crash details via Windows Event Viewer -> Windows Logs -> Application.

Please email the MuLab log file and/or Windows crash report together with a description of what you were doing just before the crash to MuTools for research.

When playing back my composition, sound is bad, music slows down and the CPU meter is in red. How come?

You've exceeded the power of your CPU.
So the audio engine has not enough time to generate/process all audio in time.
That results in clicks in the audio, or in a stuttered sound.

These are the critical parameters that define the CPU load:

  • CPU speed (the higher the better)
  • Number of CPU cores (the more the better)
  • Samplerate (the higher the better sound but the more CPU intensive)
  • Blocksize (the smaller the more instant the time between MIDI notes and their sound, but the more CPU intensive)

I sometimes hear short beeps or notice other odd unexplainable things, how come?

The integrity of the MuLab.exe file is protected by the MuLab.ID file against illegal cracking.
When the MuLab.ID file does not match the MuLab.exe file you'll hear short beeps and encounter other malfunctions.
Solution: Reinstall MuLab from the official download site so to make sure you have an authentic MuLab installed.

On startup the app alerts: "Can't find graphic resources".

Make sure you have unzipped the complete MuLab zip package into a proper MuLab folder structure thus with sub-folders "App" and "User" etc.

On MacOS, from time to time i hear clicks in the audio while it's sure not to caused by a CPU overload.

The cause may be outside MuLab.
Try lowering the priority or completely disabling things like Spotlight.
Search the web for more details from MacOS system experts.

How can I import an audio file?

You can import audio by using Audio File Clips.
There are several ways to insert a new audio clip:

  • PROJECT menu -> Import Audio File. The audio clip will start at the position you last clicked on in the composer.
  • Click the [+] track button -> "Add Audio Track".
  • Draw a new clip in the Composer using the pencil tool, then choose "Audio File", then browse for the file you want to play. This will only work if the track you're drawing a new clip on is suitable for audio clips i.e. if it's connected to a rack/module that has audio input, otherwise you would not hear anything of course.
  • Drag & drop the audio file(s) onto the [+] track button or onto the composer. You can start the drag from the integrated browser or from outside the app via a MacOS/Windows drag-drop.

Once you got your audio clip, you can double-click it to edit it in the Audio Lab. There you can also trim the start point.

How can I bounce down MIDI instruments to audio tracks?

If you want to get the sound of your MIDI instrument into MuLab, you have to record the audio output of your MIDI instrument.

If you want to turn a sequenced plugin instrument into audio, then select the relevant clips and choose File menu -> Mixdown Audio.

I did a mixdown with "create new clip" checked. The audio clip appears in the composer and plays fine but I can't see any meter going up and down in a rack. Why?

By default, the new clip which results from a mixdown is routed straight to the main "Audio Output".
This is because a mixdown is expected to contain everything and so MuLab by default assumes it's best to stream it 'dry' to the audio output.
So that's why you didn't see any level meters moving because the mixdowned clip didn't go via a rack.
Of course you can easily change the target module for the mixdowned clip e.g. to a rack, and so it's easy to further process the mixdown if you want.

I just saved my project and chose to close MuLab. Now it's asking me whether I want to save! Why?

To avoid that question alert there should be an internal mechanism that can track each and every change to your project.
If the project has changed, ask to save, else no reason to ask that. So far so good in theory.

But practically it's not always possible to know whether a project has changed, especially when using VST2 plugins.
Because there is no simple or documented way the host can know whether a VST2 plugin has changed or not.
The VST2 parameter data can be tracked, no problem with that, but it's about the non-parametric VST2 data.
For example NI Massive's LFO curves are not stored as parameters but as binary data.
That non-parametric VST2 data is bulk dumped to the host and it's not clear whether anything has really changed in it or not.
A binary compare of such data would not work as certain data could include the current date, or certain random numbers, it all depends on the VST2 plugin.
So in the end it will be the user who has to remember whether he/she changed something or not.

Another aspect that complicates analysis whether a project has changed or not:
Imagine you have assigned a MIDI CC to a parameter.
Now you save the project in a certain state with that parameter at value X.
Then you tweak the MIDI CC and so the parameter is changed and your project sounds different.
Should that change be tracked or not? I checked other DAWs and found that this is not always tracked.
An ambiguous case.

It's not that simple to automatically decide whether the "Save project?" question should come on close/quit.
So MuLab stays on the safe side and asks it anyway.
Other DAWs may appear more 'finetuned' at first because they only ask it if they tracked a change but then there is a real risk you will loose untracked changes!

I sometimes hear audio clicks and the CPU meter is high up. What computer do I need to buy in order to avoid getting this overload?

It depends on what up you do.
If you're using sample players with lots of big sample libraries then the amount of RAM is very important of course otherwise your system will start swapping RAM to disk which can lead to drop outs.

If you're using very CPU intensive plugins and/or synth sounds with long release times (i.e. many polyphones) then the more CPU power you hav the better.

In general: The more powerful your CPU and the more RAM the better.

Also these 2 tips:

  • The smaller the audio buffer size and the higher the samplerate of your audio device the more CPU this will take. Find a good balance.
  • Close as many background apps / services as possible i.e. tune your system for music production. Google about it.

Can i use MuLab on Linux?

Although there is no official MuLab version for Linux version (yet), here are links to info pages about how to use MuLab on Linux:

Can I sell/transfer my User Key to someone else?

No. Cfr the User License Agreement MuLab User Keys are personal and not transferrable.

The reasons are these:

1) A MuLab User key is a personal key and may not be given to anyone else. IF user keys would be transferrable, there should at least be an admin fee for creating a new personal user key and updating the database.

2) If the original user has got support on using MuLab, and the new user would also ask for support, then we're doing bad business for that's 2 times support for the price of one. And where would that end if that second hand user also transfers his user key, and so on and so on. That would mean that, at least theoretically, selling 1 user key could lead to supporting many people, and would cost us much support for almost no income. That would simply not be fair, not to MuTools and not to all users as they will implicitly suffer from that bad business. (e.g. slower development) So in fact IF user keys would be transferrable, there should also at least be an renewed support fee. (in addition to the admin fee)

3) When the original user has used MuLab for some time, we think he has taken advantage/consumed a portion of all the R&D work MuTools has put in creating these products. This R&D work takes time and money of course. IF user keys would be transferrable, this would decrease the return MuTools receives for all the work. And so this should be compensated in some way, for example by raising the price. But we prefer to keep the price low and to use personal user keys.

4) Summing all the above reasons and related costs simply leads to the conclusion that it's totally fair to ask a new user to buy his own personal MuLab user key. Certainly taking the low prices into account!

Why a zip package and no installer?

It has the big advantage that the user has full control over what he adds to his system, it is fully transparant.

In times of complex system setups and system attacks etc, the transparancy of a zip package really is a great advantage.

Another advantage is that a MuLab installation (ie MuLab folder) is very independent of the system, which makes it very portable.

And also: In case you would want to 'uninstall' MuLab from a certain system it is as simple as deleting the MuLab folder and there is no garbage left at all, nothing.

How long do i get free updates for MuLab 9?

If you buy a MuLab 9 App user key, you get all updates of MuLab 9 App for free.
If you buy a MuLab 9 Plugin user key, you get all updates of MuLab 9 Plugin for free.

Your MuLab 9 user key won't work for new main version like MuLab 10, MuLab 11, ...
but you can always upgrade your current MuLab user key to the newest MuLab main version for a gentle price via the MuTools shop.

I found a cracked version for free. Is it ok using it? What should i do?

No it is not ok using it, for several reasons:

  • MuTools is a small company driven by an indie developer who tries to make a modest living from his passion for music and technology.
    The price of a user key is very gentle and that money is used to pay the bills so R&D can continue and new improved versions can be developed.
    Purchasing a user key means respect and appreciation for the current version and also supports the development of new versions.
  • MuTools products include a protection mechanism and when it would detect that someone is using a cracked version it may start doing odd things and disable saved files, maybe only at a later point in time.
  • Using cracked software also is very risky because the crackers could have inserted malware in the cracked version that can seriously harm your computer.
  • It is illegal to use pirated software therefore distributers/users of pirated software risk a lawsuit.

Conclusion: It's wise not to use cracked versions but only to use the real thing.
MuTools user keys are very gently priced so hopefully everyone who wants to use MuTools products will choose the positive way and thereby help to grow the product.

If you discover a cracked version or a distributed user key please report this to MuTools via


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