This is a custom engineered high power woofer designed for use in any Cerwin Vega speaker system where 15 inch foam edge low frequency drivers were used. It is a direct retrofit with no alteration necessary. Simply remove your old woofer and install this one with the same wire connections. Cerwin Vega factory midranges and tweeters are already plenty loud enough to provide a good balance with this woofer. So... Why was this speaker built? We conceived this project simply to give Cerwin Vega  owners some more power handling in the bass frequencies where it is desirable and to give them an "American Made" component like "back in the day". Our woofer is carefully assembled, here in the USA, one at a time to give you a perfect speaker. This woofer will fit into the 13 3/4 inch holes of vintage cabinets. The sound character is very similar to what you're already used to. We've achieved that with 300% more power handling! Every one we will ship is power tested immediately before it's put in the box for delivery to you! We want you to think and say; "Wow! These are really nice, the bass is awesome, and ARC are good folks to deal with!" We will do whatever is necessary to take care of you! Thank you for looking!