Red Cymbals re.vol Series. re.vol is an abbreviation for Reduced Volume. The re.vol series is volume reduced by approximately 20% due to the laser drilled holes around the bell and edge of the cymbals. The effect of the holes is to reduce the overtones of the cymbals and shorten the decay. They are great for use in environments where less overtones and wash are needed to help the cymbal 'get out of the way' quicker.