Just for the record...I posed this "Volume Increase" question on two other BlackBerry-specific forums, and have tried every setting, situation, and "voodoo chicken dance" that was recommended...with absolutely zero increase in any area.
With the Profile
set to "Loud"...the default volume
setting at 100%...and the side volume button turned up to maximum...
...that seems to be the loudest that the 83xx will get. Sad, but true.
Mine is still very usable, and acceptable...but more would be more better!!