Rythmik has three years. Many subs make it to five years and beyond, but you have to take them on a case by case basis. Hsu subs are reliable, I wouldn't worry about getting an extended warranty with them, they are not likely to fail within 5 years. Rythmik subs also seem reliable, you don't hear much about failures from them. Some companies in the past have had such horrendous reliability issues, it basically killed them. Elemental Designs, and maybe Epik. AV123 had huge reliability issues with their popular MFW subwoofer, that wasn't what killed them in the end, but it sure hastened their downfall. Heat is the enemy of electronics electronics, if you ever hear of any amplifier that runs hot, you should worry.