So, I’ve finally updated Omnisphere 2 to 3. Took a backup of the Omnisphere subfolder inside the STEAM folder just in case (figured the third-party libraries, Trillian etc. won’t be affected by the update), then drag ‘n dropped the STEAM folder hosting the new Omnisphere 3 library on top of the old one as it is commonly suggested.

Some files were replaced, I think some new ones were added and things look ok for the time being, opened a few projects with Omnisphere 2 instances (including third-party libraries) and everything seems to load correctly.

However, since the new soundsources are located in:

C:\ProgramData\Spectrasonics\STEAM\Omnisphere\Soundsources\Factory\Core Soundsources (51.7 GB)

and the ones from Omnisphere 2 in:

C:\ProgramData\Spectrasonics\STEAM\Omnisphere\Soundsources\Factory\Core Library (53.9 GB)

the old ones (Core Library) stayed around. I guess I am supposed to simply delete this? I found the fact there is hardly any mention about it quite weird (only found 1-2 cases talking about it but without mentioning how they handled it) and since I wouldn’t want to screw up my Omnisphere installation by deleting Core Library if I shouldn’t or try other random stuff such as merging “Core Soundsources” and “Core Library” folder (this doesn’t seem right…) I thought I’d just ask around just in case.

 

I guess that if you're no longer using Omnisphere 2 there shouldn't be any problems or issues by deleting the folder but if you want to test that out just rename your Omnisphere 2 Core Library Folder to something like Core Library2 or bak or whatever you consider, not just deleting it at first, try loading your projects on Omnisphere 3 and if nothing wrong happens, there you go, you have an unnecessary 53.9GB folder. You can delete it if nothing happens on loading.

 

You could have just done a fresh install of Omnisphere 3 with the core library & the Bob Moog (including last Moog update). That alone is 59GB.
Keyscape is another 74GB. I have not reinstalled the Extensions yet. Rarely use them.

Keyscape & Trillian have their own STEAM sub-folders that Omnisphere can access so, there should be no worry about redundant content. Third party libraries with installers will usually go into the correct location. Most likely the User sub-folder under Soundsources. Other library packages (Vangelis for Omnisphere.omnisphere as an example), imported using the import utility in the Omnisphere 3 standalone get placed in the User sub-folder as well.

The Omnisphere documetion has guidelines on stalling 3 over 2 cautioning to backup projects & settings. Also after installation opening projects & adjusting patch es & settings in Omnisphere 3 as needed. All the old Factory Patches are there, just categorized differently. This is the method I used. Only a few patches/presets needed to be pointed to in my case.

The only iffy point would be libraries without any kind of normal install method. These were a headache going back to Omnishphere 1.

 

I simply copied the new files over the old ones.

C:\ProgramData\Spectrasonics\STEAM\Omnisphere

Soundsources = 53,9 GB

 

Last edited: Jun 5, 2026 at 8:24 AM

I think I had a similar experience upgrading Omnisphere and making sure I fully replaced the 2 library while keeping everything intact

 

If you mean copying the new STEAM folder coming with Omnisphere 3 library over the old one (mine), that's what I did. But as I said in my original post Core Soundsources folders for Omnisphere have different names so how come you didn't end up with both?

If you mean copying the new core soundsources library (Core Soundsources) over the old one (Core Library), again you'd end up with a soundsources library virtually twice as big because the .db filenames are different, so I don't think anything would actually get replaced.

What's also confusing is that 53.9 GB is the size of your new, updated library while that's how much my old one is (new one is smaller)... Unless you meant the factory folder, meaning including the Moog Tribute Library (2.24 GB). If so, yeah the new Factory folder is 53.9 GB here too.

Moog Tribute Library 2.24 GB
Core Soundsources 51.7 GB

These two are the contents of the factory folder and that's 53.9 GB.

Well, clean install would mean adopting the new STEAM folder and manually copying over all the other folders needed from my old one (third party libraries, trilian, extensions, custom patches etc.) and I figured just copy the new one over the old would be less prone to mistakes, especially since this is the way suggested and since I saw there is nothing in the new STEAM folder that would replace/screw with the non-Omnisphere stuff/the Satellites.

Yeah, yours was one of the posts I found when looking it up. What do you mean exactly? Completely deleting the old Omnisphere 2 Core Library folder (53.9 GB)? Merging the two folders I mentioned would hardly replace anything since the filenames are different and this can't be right.

Yeah I'm keeping the Core Soundsources (51.7 GB) folder for now but it is not exactly convenient keeping it for too long due to its size.
Problem is I use Omnisphere in so many projects and confirming for each one would take ages but well, I suppose I'll have to do that.
The thing is, since copying over the new STEAM folder and merging it with your old one is the recommended approach but no one seems to acknowledge you'll end up with the two >50 GB soundsource folders that way, contrary to how people usually act online, I am not arrogant enough to think that the instructions are wrong/not clear and I assume by default that there must be a mistake on my part. Which is what I am trying to figure out, but no one seems to be able to confirm whether they also ended up with two soundsource folders and what they did with the old one.

 

Last edited by a moderator: Jun 5, 2026 at 5:27 PM

I have this file on an SSD:
"Spectrasonics Omnisphere 3 STEAM Core Library"
I extracted it using WinRAR, and the actual size is: 56,7 GB

The advantage of overwriting is that nothing gets lost; existing files are simply overwritten, and new ones are copied over.

Spectrasonics has surely optimized a few things:

• Library Optimization: Over 26,000 patches, with all content utilizing lossless optimization to maintain the original 64GB disk footprint. Source: www.kvraudio.com/omnisphere-3-boldly-going-everywhere