If you haven’t noticed the sound of new drivers today, you can now take out your ear plugs. As driver heads have become much larger and we have thinned the titanium (or carbon) to paper-thin proportions, the sound at impact is resonating much more than their smaller counterparts. This is just the beginning as we are now starting to see some unusual shaped drivers enter the market which will further enhance the acoustics. Once the USGA imposed a rule regarding the maximum size of a driver (460cc), manufacturers have had to rethink the shape in order to create new innovative designs and stay within the size limitation.

This starts with the crown. Tradition has created an aerodynamic shaped crown that has long stood the test of time. However, the rounded crown (convex shape) does take up a certain amount of the overall volume of the club. By flattening the crown, this reduces some of the volume that can be then used to expand the dimensions from front-back. Going even one step further, the crown can be inverted (or a concave shape) to yet reduce the overall volume even more.

What does this have to do with the sound? As the crown becomes flatter and the area of the crown expands greater in dimension, a higher pitched sound will occur at impact. As heads have gone from traditional pear-shape to more full-bodied or even square shaped, the crown has been flattened out. In some cases the crown has been dished out or inverted like the Cleveland Hibore, Dynacraft Avatar Inversion or Nike Sumo (can be considered a recessed crown). These will be the loudest acoustically upon impact.

Go back in history when metal woods first started competing against wooden woods. Traditionalists were less than pleased with the sound compared to what they had been using. In 1991, when the original stainless steel Big Bertha came out, well…that was loud. Pundits scoffed and said that would be a flash in the pan because no one would want a driver that loud. It is a good thing that customers didn’t listen and stop buying the new equipment. In both cases, the new technology created much more playable heads than previously available and the louder sound at impact became accepted by golfers and eventually became the norm. Right now the jury is still out on the new, innovative shaped driver, but if they perform, the rest will be history. For those who can’t stand the sound, look for traditional rounded crown drivers or you can put your ear plugs back in and see what new the advantages technology has to offer.

by Jeff Summitt
Hireko Technical Director
jsummitt@hirekogolf.com
03/28/07