Sealed vs Ported Subwoofer (Differences & Considerations)
What are the differences between a subwoofer and a woofer? Which is better? Can I use a sub instead of awoofer or vice-versa? - Quora
Car Subwoofer Functions & Benefits for Travel Entertainment | Wuling
One unit (not pair) |15 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-15 - Lii Song (Lii Audio), unique speaker, amplfier, quality and cost-saving parts for HiFi DIY