Symmetry-based RNnv pulse sequences [Chem. Phys. Lett. 321 (2000) 205] provide efficient dipolar recoupling in magic-angle spinning nuclear magnetic resonance. For homonuclear and heteronuclear recouplings, we demonstrate analytically, numerically, and experimentally that the dipolar scaling factors may be increased by replacing previously introduced pulse elements of such sequences by windowed ones. In the case of the sequence R14(2)(6), we obtain experimentally 65% faster buildup of C-13 double-quantum coherences in uniformly C-13-labelled glycine and alanine powders, and a significantly more broadband recoupling. We also discuss the limitations of the proposed windowed pulse sequences and their use in other recoupling scenarios. (C) 2003 Elsevier B.V. All rights reserved.