weither its .1 db or 3 db its still higher, if somthing as simple as rounded corners in side the box can give .1db and it adds a slight amount of strenght to the box then why not do it? when building a box you have plenty of scrap wood anyways. this is called fine tuning the setup, wich means to make those little changes that will make it that small amount louder.
if i wanted to gain another 3-10 db i would get a second amp and 2 more 12s. im looking to do better then a 145 in which i know i can with what i have, with the 1 12 i did a 143.9, people have seen as much as 3 db from doubling the cone which i did when i got my second 12. people have also seen as much as 3 db from an upgraded electrical in which i have a 250 amp alt that does rated at 1800-1900 rpm so there is another gian. now if i only gained 1db from the doubling total cone size and 1 db from the alt thats still put me at 145.9 then i round of the corners of the box and gain that .1 db that put me at 146db running 2 12s with 1880 watts rms according to the birthsheet for my amp. that would be where i want to be by the end of april. thats all low gains from the improvments im making to the last setup i could gain a whole 6 db from doubling cone size and the upgraded alt. i dont expect that much but i know i will do better then a 145 if i get to 147 from these changes ill be extremely happy with it but if by chance i gain that 6 db that would put me just below 150 but i dont think it will go any higher then a 146.5 to be honest.
hn155: Rockford punch pro speakers, t400.4 deh 80prs, full audio build to come. working towards 175hp n/a, simple but fun.