Largely due to the popularity of the Titanic kits, we have had many requests for Dayton Reference Series subwoofer kits. And why not—they are currently the most popular subwoofer line we carry. So I thought this would be a good time to introduce a Reference subwoofer kit, and at the same time explain some of the lesser-known but useful features of the Dayton HPSA500 and HPSA1000 subwoofer amplifiers.