Altec, like JBL, designed, engineered and built 'conventional' drivers to the highest standards, getting excellent performance from proven technologies. The two 4" cone tweeters in each cabinet are excellent examples.They sound as good as much more theoretically sophisticated tweeters. The woofers are also beautifully made. They are built on a 12 inch basket, but use a 10 inch surround, with an integral metal ring that performs the same function as the famous Advent masonite ring. These speakers sound warm and authoritative and are a pleasure to listen to.