Current limiting

what voltage should I set the op-amp at to get the best response?

nevermind, i will use a variable resistor

so that is all I need then, op amp> power transistor> bulb

would the circuit in my previous post work by using an op-amp before the transistor?

I have decided to completely change what I was going to do.... I am going to mount 2 or 4 speakers inside the case and i have just baught a dual 4" blue cold cathode with sound module so I will use that and put the mic near one of the speakers

This way is cheaper, easier and there are less things to go wrong

Possibly a few minor glitches but apart from that, it should be ok