In the family of free banks, my two favourite sound banks are :
- Timbre of Heavens by Don Allen (354 Mb) (my favourite :-))
- Arachno SoundFont by Maxime Abbey (148 Mb)
Go to the first link for example, at the bottom of the page you’ll find this insert containing the link to download.

Click on the link to download the sound bank.
You will then get this window, click on the ‘Download’ button

Note :
The file will be downloaded in your « Downloads » directory.
The Timbres Of Heaven (XGM) 4.0.exe file has been compressed to reduce its size.
Double click on the Timbres Of Heaven (XGM) 4.0.exe file, it will decompress itself.
Once decompressed, you obtain several files, one of which, the one we are interested in (Timbres Of Heaven (XGM) 4.0.sf2) has a .SF2 extension, which is the extension for sound bank files.
The best thing to do, if you intend to use several sound banks, is to create a folder (called « Sound banks » for example) and copy the Timbres Of Heaven (XGM) 4.0.sf2 file into it
It will be easier to set up your synthesiser if all the sound banks are in the same place.