After researching and getting together several things together for my aftermarket radio (Pioneer AVH-4200NEX, in case it matters), I'm left a little disappointed from a constant hiss regardless of volume (including off/muted), and actual crackling when switching inputs, like activating Siri.
I asked the installer before I left, and they said it was because the head unit was overpowering the low-voltage(?) input of the amp, and that there may be an amp interface.
For reference, I used the PAC C2R-GM11B Replacement Interface to retain the chimes and other features, following the Speedo-Swap
tutorial and subsequent discussion. This is also what Crutchfield recommended, and explicitly said that I could use this to retain my stock amp.
Could he be correct, or is there something wrong with their installation?
2007 Pontiac G6 Convertible