The T70SR surround uses TriVector surround design, which incorporates a single forward-firing mid-bass driver with two phase-compensated side-firing tweeters geared to produce a diffuse, non-localizable sound pattern. The surround's four-inch woofer is made of the same molded graphite used in the T70LR without the Titanium coating. The dual tweeters are three-quarter-inch soft-dome units with fluid-cooling and dispersion enhancing lenses.