Hi there,
I've recently installed a 4-channel amp in the rear of my '03 Punto in an upgrade from a 2-channel amp that used to drive the front speakers exclusively (rears were run off the head unit... I'm cheap ). Unfortunately I've immediately run into problems.
If I plug in more than two channels at a time, (Ie fronts and one rear/all four/one front and two rears) I get massive engine noise through the speakers. With either rears or fronts exclusively, there's no interference at all!
The amp is driven by an Alpine PXA-H100 Imprint processor which also drives the amp for the subs. For the testing purposes the amps are currently mounted on a plank of MDF in the boot. Each is powered by 4-gauge cable connected to a distribution block with a 0-gauge cable to the battery.
The old amp used to be in the front beneath the driver's seat and never had noise issues. Could it be that I'm using bad grounding points? Each amp is grounded via a short 4-gauge cable to one of the four lower back seat mounting bolts in either side of the boot. They're big fat metal bolts and I'm using chunky 4-gauge ring terminals. The left-hand one (subs) has been installed for quite some time and has never had noise issues. The new amp is mounted on the right-hand side and connects to a bolt on the right, which I recall being slightly rusty.
If it helps, the amp is more powerful in watts RMS per channel than my old one yet seems to top out at lower volumes. Again, I'd love to blame a bad ground 'cuz it's easiest to fix
Image for reference, right-hand side is the new amp.
Any ideas? Cheers for your time.
I've recently installed a 4-channel amp in the rear of my '03 Punto in an upgrade from a 2-channel amp that used to drive the front speakers exclusively (rears were run off the head unit... I'm cheap ). Unfortunately I've immediately run into problems.
If I plug in more than two channels at a time, (Ie fronts and one rear/all four/one front and two rears) I get massive engine noise through the speakers. With either rears or fronts exclusively, there's no interference at all!
The amp is driven by an Alpine PXA-H100 Imprint processor which also drives the amp for the subs. For the testing purposes the amps are currently mounted on a plank of MDF in the boot. Each is powered by 4-gauge cable connected to a distribution block with a 0-gauge cable to the battery.
The old amp used to be in the front beneath the driver's seat and never had noise issues. Could it be that I'm using bad grounding points? Each amp is grounded via a short 4-gauge cable to one of the four lower back seat mounting bolts in either side of the boot. They're big fat metal bolts and I'm using chunky 4-gauge ring terminals. The left-hand one (subs) has been installed for quite some time and has never had noise issues. The new amp is mounted on the right-hand side and connects to a bolt on the right, which I recall being slightly rusty.
If it helps, the amp is more powerful in watts RMS per channel than my old one yet seems to top out at lower volumes. Again, I'd love to blame a bad ground 'cuz it's easiest to fix
Image for reference, right-hand side is the new amp.
Any ideas? Cheers for your time.