Might need to re-adjust the input gain since you have different head units. Also, what sounds great in one car may not sound as good in another. Maybe he has the speakers in a bad location.
I recently upgraded my system and gave away my old p2002 RF amp and 10" alpine subs to my neighbor. They worked great in my car. In his it is hardly getting any power to the 10" subs at all. The subs are good (I just pulled them out of my car) but sound is extremely weak in his car. Only thing I can think of is either his head unit has issues or the rca's are bad. I checked and ground and power supplies are good
What I mean by weaker is I can barely hear the subs. The gain is set at about 3/4 and there isn't much of a difference. He put a meter on the ground and it was fine
what kind of car was the stuff in and what kind of car did the stuff get put in, could also check phase.
Zapco Reference 360.4: H-Audio Soul, x2 right side
Zapco Reference 360.4: H-Audio Soul, x2 left side
Zapco Reference 500.1: JL Audio 10W3V3 Stealth box
A bad ground will have resistance that will only show itself by lowering your amp's input voltage when current is passing through it b/c of Ohm's law (V=IR).
A bad ground will look perfectly fine on a meter if your system is not running. Have you tried testing the voltage between +12V and GND while the system is running and playing music?
aye.. am i reading this correctly...? running subs directly from the head deck??
and phase isnt really an issue, sure it will sound different but if you hooked teh speaker up out of phase you'll still get output.
check your leads. When people take gear out of our shop to use they give us a call at 2am in the morning, we get there, and they are using their own crusty lead and not the ones we supplied. The leads are always the weekest link.
next is a switch or knob or function etc thats turned on or switched into the wrong position.
Plugged it into the wrong output? sorry had to ask XD