The R65 and R80 feature a custom 6.8-square inch Air Motion Transformer (AMT) tweeter that responds to the subtlest waveforms and the highest frequencies. This allows you to hear the air and the greater sense of space that is characteristic of audiophile recordings. The R series' transparent and highly accurate sound makes them ideal for use in both commercial and home recording studios as well as broadcast and post-production environments. In order to dampen resonance peaks at higher frequencies, conventional dome tweeters are injected with fluid to raise their mass, sacrificing transient response time. By contrast, the custom-designed AMT tweeter in the R65 and R80 uses an incredibly thin, folded Kapton membrane (< 0.01 mm) with an inlayed aluminum circuit functioning as the voice coil, allowing the tweeter to move at the same instant as the electric current. The resulting reactive response time provides marked clarity and superior transient reproduction. Unlike a traditional 1-inch dome tweeter, which provides a mere 506 mm2 projection area, an unfolded AMT tweeter diaphragm provides 8 to 13 times the projection area so its sound coverage is much larger. For example, the 4,400 mm2 PreSonus R65 and R80 tweeter provides coverage equivalent to that of a 3-inch dome tweeter. This enables the R-series monitors to provide a much wide stereo soundstage than traditional designs.