hey guys, I've spent all week doing wiring and tearing apart my car for an audio install (JBL components and an infinity sub off a JL XD500/3).

I'm trying to set my gains right now but I ran into some issues. Per the JL manual, I'm supposed to hit 14.1V for a 2 ohm load for the stereo channels. I put on a 1000 Hz sine wave through my ipod (my cd player is broken) with the volume at 30 (3/4 max).

I can't get higher than 6V with the gain at max, I'm supposed to get 14.1, is there something I'm doing wrong? Any thoughts? i wonder if playing it through an ipod is somehow affecting it, but i don't have any other options besides hooking up a laptop and using the aux port.


For the sub, i played a 50 Hz sine wave and was able to get my sub gains correct (26.8V for 2 ohm load), but the remote bass knob really had a big impact on moving the voltages. is this normal that the remote knob had such a big influence on setting the amp output voltage?

thanks for any help, i'm trying to knock this out this weekend so i can put my car back together.

 

so i set it up again using a laptop to provide the sine waves through the aux port. i can reach the voltage settings if the laptop and windows media player on full volume. is this how i should set my gains since i can't use my cd? not having a cd player really throws a wrench in the mix...

 

Ideally you want an uncompressed sine wave at 0dB. Doesn't really matter the format you use to get it. FWIW, the OEM headunit is clean at full volume. Even at 30 though which ought to be ~500mV output you should be able to get your amp to read in excess of 25 volts on the output side. Granted, that is clipped all to hell, but it should do it.

 

bump, spent all night tonight trying to set gains again and the question has changed from the OP.

i use a laptop at full volume, HU at 3/4 and set the voltage that i need. however, once i take away the laptop, the bass is super weak and everything sounds off. the volume on the laptop basically controls the gain and once i remove it, the gain is way off for the HU

can anyone help?