Hmmm... What do you assume is the reasoning to lie about the power handling of the cabs? So people buy two?
Precisely: Ampeg must have figured if someone could afford a full SVT stack, they should go for the upsell. Decades of players using SVT's and other big heads on a single cabinet with no problems holds a lot more water than 70's ad copy.
That info is right out of a 1973 Ampeg catalog BTW, not online.
I know. Unfortunately in the 70's, Ampeg got caught up in the BS wars that were common among musical instrument amp makers. Acoustic, Fender, Gibson, Sunn, and especially Peavey (along with a bunch of others), liked to 'fudge' things too.
So what IS the actual power handling of a 70s SVT cab? I built a 410 version (2 sealed chambers...) and loaded it with speakers out of a 70s Ampeg. Would like to know the real handling ability just for the hell of it.
No one has ever actually driven an SVT speaker to destruction to get its rating and published it, but Ted Weber was shooting for a 40 watter with his unfinished CTS clone before he died. In the early days of Talkbass, an Eminence rep checked the numbers on the drivers and that's where the 100 watt rating for them came from, but a few years later, that info was apparently lost by Eminence. I know I put over 400 watts of heavily compressed tube power into my oldest cab with all stock CTS speakers and it has never barked. I did some sweep response tests on mine years ago, but offhand, I can't find any of the raw data; I just remember being pleasantly surprised at quite a 'few nuggets of wisdom' in regards to the SVT cab being soundly proven false. You can probably safely consider your 4x10 at least a 200 watt cab as long as it is sealed.