In the SVT 210 boxes, the SC10's go deeper and are slightly less efficient but will play louder than the stock Ampeg drivers. They are also more neutral and less colored than the stock. They move much more air so they deliver more punch in the low mids. I haven't done a careful A/B comparison, but the SC10s possibly give up a little definition vs the stock, but this is probably due to the additional low frequency content.I'm curious about what you thought comparing the stock svt210av drivers compared to the sc10?
The small enclosure volume of the Ampeg boxes are a limiting factor in terms of the bass response of the SC10s--in the custom boxes that Don built for me (circa 1.9 gross volume for the 210) the SC10s put out MUCH more bass than the stock 210AVs.