That picture makes a lil no sence. To hook it up to an 1OHM load, you should only have 1 positive and 1 negitive like in the rockford fosgate picture. If i'm all wrong, tell me and exlpain a little more better. Thanks
The amplifier has two terminals for convenience. That's not the problem. JBLs tend to work better with all 4 RCAs used, try getting a y splitter for each side and put those on there and see if the sound improves. Since you're using the head unit's crossover, turn off the crossover at the amp(or turn it all the way up if you can't turn it off, can't remember about the 1200.1). Gain settings are hard to tell and honestly, to properly set them you'd need either an oscilloscope or a voltmeter and a 0db reference tone to get accurate results. Make sure your ground is solid, and you're using proper guage wiring. Also, when the subs seem to fade, make sure the electrical system (alternator) isn't straining and voltage doesn't drop dramatically. You could be experiencing a current delivery problem.
I know its not the alternator, i have a 20 farad cap. The wiring is 4 guage. I try the gain all the way up on amp and 0 on head unit and see what happens. By the way, can you please explain to me how to properly break in new subwoofers? Thank You.
You said you have your crossover at 40hz. It should be atleast on 80hz your probably blocking the tones you want to hear. Also try everything Jonathan said. Try turning the head units crossover off an use the one on the amp, sometimes head units crossover arent to accurate.
I turned the BSE setting on the pioneer 860 mp off... and it seems okay.. but when it does get a high volumes it does tend to get funky beat. Like If I play a song that goes: example: BOOOOOOOM - it will cut off like so. BOO_____OOO___M cutt's off and on inbetween..
I hope the example made sense to you all. ( dont think i'm crazy ) =] lol
Break the subs in first. When subs are newer, the suspension is tighter and the voice coils will need to burn off excess glue. Your gain shouldn't have to be set all the way up, 60% or lower is usually about right, you should try setting the gain lower and see if that helps as well. What kind of subs are we talking about here? What kind of enclosure are they in? Try setting the crossover higher like Joseph suggested. Definately try the Y connectors as well. Make sure all the wiring is tightly mounted, not frayed in at any point, and that the subs terminals and leads are good.
www.4alterstart.com has the 2001 to your car but the 2001 might fit there number 1800-607-0016. If that doesnt work this site www.motorcityreman.com can build you a new one from scratch heres there number 586-773-2089. Or you might have to find a locla shop that can upgrade you factory alternator to a HO version. good luck