How to calculate T/S parameters for a Pro Tech subwoofer
I have a pair of Pro Tech CH12D4 subs. There are no longer any published specs that I can find. PJ's gave all the data away when they sold the Pro Tech brand almost a decade ago. I want to build a band pass box for these subs but need T/S specs to calculate it. I know I can buy a speaker calculator from Dayton Audio, but is there another "cheaper" way to do it. I have a multimeter, but that is about it. Any help would be great.