Here's an amp question for those in the know...
It's said that to double the output volume of an amp you need to increase the wattage ten fold. Said another way, a screaming loud 300 watt Ampeg SVT which can easily exceed any safe or sane volume levels when connected to an 810 cab is theoretically only twice as loud as a 30 watt amp through the same cab. Which if true causes me to wonder - why a 150 watt amp is considered by many as underpowered when theoretically a 300 watt amp is only 10% louder.
In real life usage I've never been able to dime my SVT-VR through my Berg 610 cab, and likewise I've never been able to dime my Musicman HD150 through the same cab. Both are incredibly too loud to max out at any normal indoor venue. However, the advantage I get with the Musicman is I can half the output to 75 watts and then crank the volume for some very sweet tube overdrive, that's harder to do with the SVT-VR which wants to stay fairly clean even at high volumes. Just an observation.