Uploading Audio/Video/Images
Installation and Configuration
You can see the max upload size in your system check...
ACP > Core > System Core > Tools > System Check
yoursite.com /core/system_check
If that is set at what you want, then you can change the max upload size in your ACP > Core > System Core > Quota Config for each quota.
As for testing, try using the Gallery module, it allows multiple uploads.
Hope this helps.