I am new to posting in this forum but have been reading the archives and am impressed by the knowledge shared herein, so I am posing a question concerning the sound-box resonance of the typical DB. The question - why is the resonance frequency of the bass cavity not tuned lower? Background - I have built reflex ported-box bass speaker cabinets using Thiele's acoustic design parameters and I applied that method when I built two small upright acoustic basses. The basses were based on Music Kit's Baroque design. The first lacked loudness. I experimented and greatly improved version II by tuning the resonance of the sound box to low E (41 hz) with a port (hole) in the front. The hole also serves to reach in and set the sound post. There is a single f-hole on the base side. The improved model is about the size and loudness of a 2/4 bass but seems to have a better bottom register. I recently bought a '02 C1 Engelhart and was disappointed to find it resonated at about a C or D. I began to wonder why bass manufacturers do not lower the resonance to smooth the mid response and increase the loudness of the lower register. I researched forums and other links and found a research paper about what makes a good sounding double bass. About eight or ten different basses (cheap and expensive) were tested but not named. It was found that the best sounding (expensive) basses had a low box resonance (large) and a low top plate resonance (thin and flexible). It was also noted that the lower half octave rolled off severely for virtually all basses tested. I have since lost that link. In estimating the volume of my C1 I found it to be approximately 4 cu ft and that it would take about a 3" dia. hole to drop the cavity Fb resonance to 40 Hz. Judging from the experimentation with my home-made bass, this would greatly improve the low end and remove the peak boom from the C and D notes. So - if it is THAT simple to make a significant improvement why am I the first to notice? I am not ready to take the hole-saw to my C1 but I cannot find any more info. Any thoughts or opinions would be most welcome. Thanks.