I used the 7551 Metra harness to install a Pioneer AVH-X4500BT, and it sounds fine up until higher volumes, where it starts to clip out, it affects the display and I am wondering if it is because of the harness? Or should I look for a better ground? I went the cheap route on the harness because the headunit has 4V outputs, so I figured it would be fine. It feels like the more bassy it is, the more likely it is that the clipping happens. I'm done working on it for today, but wanted to see if I couldn't get some ideas from you guys? I've searched through the forums but couldn't find anything related to this issue.

 

A bad ground is definitely a possibility. The harness ground is absolutely horrible. I would try finding a better ground first and then go from there.

 

http://lmgtfy.com/?q=How+to+search+on+maxima.org

 

Thanks Fakie, your post was extra helpful... You used the 7551 harness right rebel? Where did you end up grounding it?

 

Yes, I have an AVIC-Z140BH connected with the 7551. My ground is probably overkill but I ran a wire from the harness to the radio chassis, then from the radio chassis to the factory body ground below the left A-Pillar.

 

Ok, so I think it's because of the RCAs. The preamp outputs are "4V" but it just sounds as though the factory amps arent getting enough juice. I still have that popping through the headunit and speakers at high volumes after running wire and grounding it as well. Leads me to believe the amps are at their max well before the headunit volume is, and the audio is reproduced quietly. I guess I am not sure which route I want to go from here, as the 7551 harness was so easy to install. I dont want to take it out and undo everything to put in the PAC kit. Any ideas? I had read about ground loop isolators, wondering if that might help out?

 

Ground loop isolators will only have an effect on radio reception. You can try but I doubt that's your issue. My money is still on the ground. I'd double and triple check your ground. Try a couple different places. There's really no place decent behind the center console, I had to run mine over to the A-Pillar.

 

Clipping doesn't sound like an issue with the way its wired. Sounds like an output level issue. Is your bass boost on or output gain maxed out?

Ground loop isolators are bandaids. Don't use em. Find the root cause.

Where did you get the HU? New with warranty? Are you sure it's not defective? I've seen enough issues with Pioneer outputs to question the integrity of the RCA outputs.

 

It's a line output problem. I've narrowed it down to the fact that these outputs probably arent 4V. They say they are, but thats probably at peak. Which is why it's quieter and when brought up to higher volumes, the Bose amps are already at their max. Or am I missing something? I bought it new with warranty off Amazon, they would exchange it worst case scenario, or take it back. I ordered the PAC-ROEMNIS2 and if I still have the popping/distortion, I will call it a day and go back to the Bose headunit/cassette adapter.

 

^^ Sounds more likely. Pioneer has always been 'interesting' with regards to their preouts.

 

See, I really didnt know too much about their inputs. I always figured it said 4V, so it must be 4V. I am going to call today and complain to them. When I take it out to wire of the PAC kit, I am going to test the outputs with my multimeter, and see what they truly output.

 

I have a Pioneer AVIC Z140BH and have no problem getting enough volume to distort the speakers. It's labeled as having 4V preouts and works just fine.

 

Happens, and I suspect you're right. 4v is probably their max output, not consistently 4v.

So in terms of the amp picking up a strong signal, you're probably just under the threshold of it being powerful enough. LOC should fix this without issue. ROEMNIS2 is just a glorified LOC.

 

Which further proves the inconsistency I've noticed among various Pioneer HU's.

 

Perhaps Rebel yours is a higher end model? This is a mid-tier headunit from their 2013 lineup. I got it because of the "4V" outputs. My first initial thought from installation experience was a shoddy ground. So instead of the harness ground, I ground to the chassis with no better results. I'm going to rip it out in a couple hours and I will post what my multi meter reads

 

I should measure mine one of these days. Would be interesting to know. Of course I plan on replacing all of the factory speakers and amps soon. Maybe I'll test it then just for $hits and giggles.

 

They were reading 3.2-3.4 volts. I guess that would explain it!

 

Ok, is wiring the PAC kit supposed to be as difficult as I am making it?

 

I've never used the PAC kit but I can't imagine it should be that difficult. Let me look into it.

 

More complicated than I thought it would be but shouldn't be too bad.

 

Not any more difficult than a regular HU wiring. Just additional steps.

 

Installed the kit, and voila! It took me up to volume 40 to actually reproduce what volume 17 puts out with this kit. Needless to say, make sure your headunit is AT LEAST a constant 4V when installing the 70-7551 Metra Harness. The PAC unit was a little confusing at first, but all I did was wire it directly to the headunit harness, color for color. About as plug and play as you can get. I am pleased with results, I finally have good sound after a week of quiet music and feedback throughout the system. JL components this summer, but this will hold me over til then . Thanks for the input and feedback guys. Like I said, sometimes it's nice to just talk to some people instead of pouring over thousands of pages of threads

 

Glad you were able to get it working.

 

4V is a peak rating and with artificial additives from the deck engaged. It's a fairly legit rating, but sounds like poo.

You could have saved a bunch of trouble and just used a 7550. No adapters or anything else, just a 7550.

 

I could have used the 7550 and had extra noise and feedback at lower volumes according to what I have read on this site. I dont mind spending the $40 to have it sound how I want it to. I spend too much time in my car to be annoyed with hissing. If you have a way around this, this would have been helpful to know 5 days ago when I posted the thread lol

 

Yea ...according to what you read. Also, if reading you would have seen evidence to the contrary.

There is a thread, on the very first page and prior to 5 days ago, saying the 7550 can be used.