I'm looking for a subwoofer calculator that can be trusted for porting. I used to use http://www.subwoofertools.com and it was reliable but the website is down. Preferably free and downloadable or a website.
i use re box calc all the time along with bcae. after i figure out a box with RE i break it down in sections and verify the space inside of it with bcae's internal volume calc and stuff. i've never had any issues.
I use the carstereo.com ones as well...when I calulate my port length I'm peaking(frequency wise) exactly where I should be, so I continue to use the calcs.