Hello, I'm sorry this may be long. This is the first time I'm coming to other people for help with a project. I do a lot of simple projects (adding lights to this and that, putting switches here and there), and have therefore done lots of independent research about how some of these things work. However, I am on a project now that I need a little bit of help with. One of the projects I did a few years ago was connecting a car subwoofer to my computer. In that project, I had a nice amplifier, which i then used for other projects. I went home for the summer (about to be a college senior), and since there was a foreign exchange student in my room for the school year and then for a few weeks after i came home, most of my stuff was kind of strewn across the house, and my mom thinks that she might have gotten rid of my amp. Anyway, one of the things i used my amp for (the subwoofer was kind of loud to have in the apartment) was hooking up lights to and the lights would blink with the beat. I want to get that going again with LEDs, but im not interested in spending $100 on another amp. I have been looking at stuff on ebay, trying to figure out how to do it. I want to show you guys my idea and hear back your opinions/concerns (mind you, I'm a pre med student doing biology, so I don't have any education in engineering outside of what I have gone out and looked into myself). http://forum.allaboutcircuits.com/attachment.php?attachmentid=45341&stc=1&d=1344800070 This 12v amp is what im thinking about using this amp. http://forum.allaboutcircuits.com/attachment.php?attachmentid=45342&stc=1&d=1344800083 To get the LEDs to blink with the beat, I am thinking about using this LPF (down to 22 Hz). Im read that its better to run from the original audio source, then through the LFP, then the amp, and then out to the LEDs. Does all of this seem ok, or is there a fundamental flaw that I'm not aware of? Thank you so much guys!