So, I had a Pioneer single din DEH P6000UB for the longest time, and now upgraded to the AVIC 110BT a year ago or so. Both always have had a hiss through the speakers.
I'm not talking about alternator whine, I'm not talking about a damaged pico fuse. I've had the RCAs grounded before, I have my head unit grounded directly to the car properly, and power running directly to the battery.
The AVIC has 4v preouts, and so did the P6000, but to get good power out of any of the amps I've tried, the gain has to be set to 80% or so.
So there's a constant hiss. It does not exist at Volume 0, and slowly appears as you go higher, and stops increasing in loudness at Volume 15. Then when you keep going (Volume 16,17,etc), the noise no longer gets louder, and then when you are getting towards the high 20s, starts to increase again till 30 I believe. So the noise to sound ratio is not constant throughout all the volume levels on the deck (it goes from 0 to 40).
Is it just Pioneer design? The noise floor seems high for such an expensive head unit, and I'd expect to not have to crank gains so much. I run a RF Power 550s for highs, used to run a Pioneer 5200 2ch. Both had to be cranked to gains set below 1v and both had the hiss. If I turn down the gain, the head unit will clip before the amp produces full power.
Am I the only one? Grounds are perfect, equipment is perfect, so it seems like just Pioneer design.