In one of my bands, I compared a 30 and a 50-watt amplifier. With a usable tone, the 30 was just scarcely audible over the drumset in a very large enclosed garage. The 50 watt had to be rolled back a little bit to get a good mix.
In larger live environments, you may want to 'mic the amp' and run it through the venue's PA system.
Hope this helps.
GT Admin
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