Dayton Audio RST28F-4 1-1/8" Reference Series Fabric Dome Tweeter 4 Ohm The Dayton Audio RST28F-4 silk dome Reference Series tweeter offers exceptional efficiency from 1,400 Hz to 20,000 Hz with an extremely natural and dynamic sound. This unique 1-1/8" silk dome and a state-of-the-art Ferrofluid cooled motor system employs copper shorting rings to ensure that high frequency content is reproduced as transparently as possible, assuring studio-quality performance. RST28F-4 tweeters not only match the look and features of the RS woofers and midranges but also the clean, detailed, and uncolored sound that characterizes the entire series. These are just a few of the features that allow these tweeters to outperform some the most expensive audiophile high-frequency transducers.