ok i took this from a website giving the equasion for quarter wave theory for maximum wave heres his example for 40 hz. (below) Then i did one for 36 hz because i remembered another box i had tuned to 36 hz and the fact that it was two 4 inch ports 9.8 inches deep and i came out with 93.96 inches (basically 94 inches) for quarter wave for that note. now my question is if i was that far off from first quarter wave could that seriously effect my output spl wise? (id assume so) Thoughts appreciated on this.
(1128 ft/sec)/(40 1/sec) = 28.2 ft Since the maximum amplitude of a sine function occurs at the first quarter...we will take 28.2/4=7.05 (roughly 7 ft or 84 inches)