Hissing - new Pioneer HU, no separate amp: help-a-noob

[Bad Monkey]

Just installed a new Pioneer DEH-P5150UB (equivalent of 510 in the US) replacing an old Alpine in my 2002 Ford Mondeo.

I am using bought harnesses to connect the HU: one from the Ford plugs to an ISO socket, then another from the ISO to the Pioneer.

There is no amp and the previous system worked fine (or appeared to anyway).

I am getting a small about of hiss (pink noise) from the unit which is noticeable when playing CDs, during quiet sections of music or if paused. The level of the hiss is related to the volume - pause the music and max the volume, and it's quite bad.

It does not vary with the engine, and is not affected by any of the car's controls or mechanics that I can detect.

I am not using the RCAs.

• I am going to check the ground on the harness tomorrow.
  
• Maybe the harnesses require shielding, the speaker wires in particular?
  

Other than that, anything else I should be thinking about?

Click to read more...

 

[AlterEgo99 5,000+ posts]

Might just be the HU.

I have an Alpine CDA-9887 and get no hiss on the tuner or the CD source, but get some (slight) on the iPod source. I've contacted Alpine and spoken to other Alpine owners and they simply say "it is what it is". Typically it's not too noticeable unless I was listening to classical music (which I do from time to time - love Bach and Vivaldi - AWESOME composers FTW) and was not movin' on down the road. Pretty rare instance and I love Alpine HU's in general so it's not a deal breaker.

 

[Bad Monkey]

Okay I tested the ground today - disconnected +ve from battery, ran cable from -ve to the cabin and measured resistance between that and the ground on the harness. I get 0.9 ohm. That's okay right?

Played around with the harness wires while I was out there, didn't make any difference if I moved them away from each other etc. I wrapped the battery and ACC wires in foil to eliminate any possible interference, made no difference.

Any other things I should be looking at? Linking the RCAs to the HU body is not relevant if I'm not using the RCAs is it?