Expert: Cleggsan - 11/18/2009

Question
hello, i have a question about my amp and what to do.

ok to start i have a jbl BPx500.1 amp that has 785 rms/watts and i hooked it up to 2 12 inch spl 2000 watt subs and it started to pop my fuses on the amp at first and they were 30's (2 fuses) and i replaced them with 40's and then it stays on and everything now but i have a I-E/OPT LED is on steadily,and the manual says that  the amplifier is being overdriven. and i tried to turn the input levels all the way down and i cant get the light to turn off and i dont know what to do please help me out thanks for your time.

Answer
First, remove the speaker connections from the amp so there is no load connected to it.

Then, reset the amp by disconnecting the power (12v lines) for 15 minutes.

Then, power it up with no load and with the audio feeding it set to zero or minimum audio level.  

IF:  It blows the standard fuse under these conditions it is a problem with the amp internal circuits.  Probably the output stages have been wrecked.

IF:  The fuse does not blow then the problem is most likely to be

- in the wiring between the amp and the speaker
- OR one of the subs has a shorted voice coil
- OR you have them wired wrong such that the impedance of the load is not right for the amp.

If you have it in bridged mode the impedance of the load can be down to 1 or 2 ohms but its ideal impedance is 4 ohms. If you have it in stereo it is best to keep the load at 4 ohms, also.  If the subs you have are dual voice coils may have to change the connection circuit.  

If you need more please tell me the sub model number and the way you have them loaded onto the amp.

Best wishes.