a 10" sub that hits lower than most competitors 12's.this sub has a good range to it and doesn't have a boomy bass range to it like so many subs do.And this sub can hit hard when you crank it with no distortion.also I would like to thank boston's support group.I contacted with multiple questions.I got answers the next day.Thank you for answering my emails in a timely manner.You just don't see companies today that have fantastic informed customer support.Thank you!