Amazon.com: Bandpass Enclosure Car Subwoofer Speaker - 500 Watt High Power Car Audio Sound Component Speaker System w/ 10-inch Subwoofer, 2" Aluminum Voice Coil, 4 Ohm, Ported Enclosure System - Pyle PLQB10 : Electronics
BOX PLAN Professional 4th Order Bandpass Bass Dual 15inch Subwoofer Box - YouTube
Bandpass Enclosure Characteristics – JL Audio Help Center - Search Articles
Pyramid Bnps122 12 Inch 1200 Watt Dual Audio Subwoofer With Neon Lighting And Bandpass Enclosure Box And Pyramid Pb715x 2-channel Car Audio Amplifier : Target
TSG Dual BandPass 1218 DUAL 18" Woofer 106 DB at 1 watt LOW SHIPPING!! – SpeakersAndAmps.com
Q-Logic QLH12BP.4 Dual 12-inch Bandpass Subwoofer Box at Crutchfield