Help

[eloc49]

Okay so I was installing an amp for my speakers. Originally I was gonna put a 450 watt sony, but we ran into some problems.... needless to say, me and my friends have swapped out every single component of this system. Stereo, power wire, ground wire, ground, RCA cables, even tried different amps nothing fixes the problem. The amp still turns off when the volume goes past 25 (out of 50). However, I can get it above 25 when i am revving the engine at around 4,000. The ground is getting a constant 12 volt. Here are the specs of the system:

Sony Xplod stereo
Pyle 12 guage remote wire
Rockford Fosgate 8 guage power wire with 2 60 amp fuses (OFC)
Random OFC ground wire
Home audio RCA cables
Kicker ZX 350.4

Im thinking its the battery or the alternator, but what else could it be? Every single wire is fine and the amp has been bench tested in multiple cars and in a home audio environment.

[dble0]

Take a multimeter to the power and ground connection at the amp while having somebody slowly turn up the volume. Tell me the voltage just before, right at, and right after you hit 25

[Low35]

Check the ground wires going from the battery negative to the grounding points on the car. sometimes these wires are brittle and broken. Also, even if they look ok you should replace them with some true 4 gauge power wire. Also upgrade from the alternator to the positive battery terminal as well.

[Low35]

Also make sure you are properly tuning the amps. Turn all gains and bass boost to zero,turn all the radio eq to flat and treb,bass,mid settings to 0 not -0 but 0 (in the middle), with the 4 channel amp gain and bass turned down,turn up the radio volume to 75% of its max volume, so if max is 50, 75% will be like 38. put the crossover setting on both amps to 80, this no longer needs adjusting after this. With the radio up to 38, fade to front speakers, go to the 4 channel and turn up the gain till the speakers distort then back down till its clear again. Repeat for rear. Also make sure the if the radio has a high pass filter that it's letting the least amount of bass to the interior speakers. Ok, unplug the rca from the four channel, and turn the sub level on the radio all the way up, with only the sub playing and radio turned up to 38 with gain and bass boost down on sub amp, set the bass boost to 1 or the very first line, that's it, don't put it any higher, now Slowly turn up the gain till either the sub gets distorted or the volume seems to nit get any louder then back down till its clear or the volume starts decreasing. Now plug in the 4 channel and fade to middle and you set. Now you know that everything is tune to your max volume of 38 for most songs anyway. I knw you didn't ask this but sometimes not tuning correctly can cause your problems. Hope this helps. P.s. I just noticed your not doing a sub so you may want to adjust the radio hi pass low pass filter to bring in some bass.