View Full Version : Pioneer head unit hiss?

08-07-2013, 12:17 AM
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.


08-08-2013, 04:15 PM
What type of amp(s) are you running?

Side Show
08-09-2013, 01:24 AM
4v pre-out?

08-09-2013, 08:38 PM
Both were mentioned in the post gents. Please let me know if you guys have any ideas.

...The AVIC has 4v preouts, and so did the P6000...

... I run a RF Power 550s for highs, used to run a Pioneer 5200 2ch....

08-09-2013, 08:50 PM
Just plugged my old iPhone 3 into the amp with a cheap RCA to phono cord. Plays just as loud if not louder on the same gain setting, and I'm pretty sure the iPhones output is well below 4v. Oh and absolutely zero noise, no hiss what so ever. Is pioneer not that great at all?

08-09-2013, 09:10 PM
i don't run Pioneer for many reasons, noise is just one of them.

the issue is your gain structure though. your amp gains are too high and the signal strength is too low. so you are amplifying the noise that is in the HU outputs.

some of the older Alpine units had hiss above 50% but the newer ones do not. I can be at full volume playing a digital mute track and have no noise.

08-09-2013, 10:40 PM
Fair enough, but why is the Pioneer outputting so much less then 4V? I'm surprised how much better an old iphone is in terms of SNR.