Hi all. First woodworking project is a DIY subwoofer from Creative Sound Solutions. The kit is the CSS QUARTET12(TRIO12)H, which is a TRIO 12" woofer and 2 opposing 12" passive radiators, powered by a SPA500 Amp. The cabinet used is a 24" cube vice the 20". Since volume was not a real issue and low frequency extension was, Mike P from HTS ran some models and the result was the 24" had advantages at lower frequencies: .