biggest output? as in watts? it uses a small inbuilt amp, very small watt, sub size also very small, usually 6-8 inch, u have to compromise bass for space. active subs at best only sound like loud midbass. nothing can substitute good power, good sub, good enclosure to get good sub bass. alpine have 2 or 3 models around 500-800 if i remember correctly. i dont think JL has one. other brands in the market are lesser known brands..