Im looking for advice tracking 2 different noises in my
Cayman 987.2
base amp install.
I have an existing
Pioneer Avic
Z150BH head unit (replaced my stock
CDR-30
) that had been operating noise-free for almost 3 years powering upgraded front door 2-ways directly. I'm installing a small 4-channel
Pioneer
amp (GM-D1004) into the front trunk, connecting to the existing head unit with RCA signal inputs. Also added 2 rear 4" 2-way speakers. Will be adding a small
Kenwood
powered sub under the front passenger seat (taking RCA signal input from the head unit) but I haven't run power to it yet.
The two noises I have are:
A steady static "tick" ~30/second that does not change at all with engine rpm. It drops out when I turn off my halogens headlights. Amp is powered from the battery. I originally had the amp grounded to the front trunk right-side grounding post, but moved it to the battery as a test hoping to eliminate noise but it made no difference.
A higher-pitched whirring "R2D2-ish" static that changes pitch with rpm. Didn't exist before amp install.
It should be noted that I have Loi's EuroMotorspeed adapter kit that utilizes the factory ground (from my original CD-R-30 non-amplified system), whereas my new amp now is connected directly to the battery negative...in other words, they're different locations.
Would an in-line noise suppression filter on the amp power feed solve both noises? Any words of wisdom for me to try? Thanks.
Since you had neither of these noises before installing (or usng the RCA pre-outs) I would focus on those two areas.
First, the amp, do you have another one you could try or borrow to try, it could be the amp or it's sensitivity to the noise on the DC. The pre-outs, hopefully the problem isn't there, trying another amp might shed some light on this as well.
I ran into a few problems in my 2006 when I tried to power HID ballasts off of the fuse box, eventually I had to powere them directly from the
battery
, there was a consisyant volyage drop out that prevented the ballast from staying on.
I was going to ad (before reading the last line in your post) to filter the power feed and shield the RCA cables. Noise suppressors are nothin more than capacitors. This has worked for many users in the past. RCA cables are prone to interference, especially the cheaper kind.
Update: I have a large impedance difference (to
battery
negative post) between amp & subwoofer grounds and the head unit ground (using the factory wiring). Amp and sub use existing ground lugs in front trunk (right side) and under p/s seat, respectively. Both show 14 ohms resistance to
battery
negative post. Factory ground wiring from the head unit to
battery
is about 27 ohms. Could this be a ground loop source of my noises? Should I relocate the head unit ground to one of the factory ground lugs?
This could be the cause, can you ground the amp and the head unit to the exact same physical point? I am surprised that there is any resistance between the ground
points
in the car and the
battery
...
