The simple answer is; one mandolin is not enough! As for as I can tell thse scroll doesn't really affect the tone much. The main differences (IMHO) in volume and tone come from these sources:
Tonewoods; spruce and cedar tops sound different, and maple and mahogany or birch bodies do too.
Soundholes; F holes tend to sound 'dryer' and 'woodier' than oval holes, which tend to have a more ringing sound with greater sustain.
Flat or carved top and back; Carved tops are usually louder, with a more punchy sound.
String choice; there's a world of difference in tone and volume between light and heavy strings
Pick choice; light picks produce a thinner, ringing sound, heavy ones produce the dry 'chop' so beloved in bluegrass.

Biggest difference of all? The player's hands and sense of the music they are playing.
Tim