The best-known and most sold are 12" subwoofers in a box, which have been taken as a benchmark for years. Those who wanted a subwoofer in their car most often reached for the 12" version. Today, this category is on the decline, mainly due to the larger dimensions of the enclosures. Many 10" and sometimes even 8" subwoofers in the box can replace 12" subwoofers nicely.