With regard to the shape of the bowl, were analyzed in all possible forms of Kaman known guitars. All ancient and modern instruments were X-rayed, vibrated, measured, disassembled and reassembled.
were made of each guitar sound signatures recording vibrational characteristics throughout the tonal spectrum. Some guitars gave good results, the top and chest vibrated with the right size for full scale harmonic with constant input of energy. Other the other hand had the opposite characteristics, and some showed that the nodal points, with no input of energy, were the top vibrate. After months of analysis to the Kaman had accumulated perhaps the largest collection of audio signatures (or profiles) of the acoustic guitar as possible, with these data in hand to use as a guide, develop and test every possible form "original" speaker to understand what improvements could be made. As said earlier, it took 2 years of studies and tests and 70 original drawings before we see the birth of the "bowl" as we know it today.
The bowl was (and is) that returned a dish so rich, clear and deep, the energy imparted by the top, with harmonics that were no longer than fundamental tones. An ideal form as that of ancient lute that it recalls. Officially opened on 14 November 1966 with a gala dinner at the Hotel America in Hartford, Connecticut in the presence of 300 guests, including journalists and industry experts. No scientific instrument was necessary to make it clear to all defendants who first heard the debut of the new guitar, that something extraordinary had happened in the way of producing acoustic guitars. That night they performed the Balladeers and Josh White, the first endorser Ovation.
The Ovation roundback was probably the most important scientific advance of the last 400 years in the manufacture of guitars.
PS: The first picture was extracted from a brochure of the time and shows the stack of "shoes" of fiberglass and the press, where a once inserted, are impregnated with resin and pressed into shape to form the "bowl".