Ground loops and proper wiring? Home Run? HUM, Hiss, POP

[WakesetterE]

I'm chasing a ground loop and I want to clarify a few things.

When they say run all grounds to a common point, does that indicate each item (head unit, line driver, etc) have an individual ground wire home run to the battery negative terminal? Or, can you hook two items togeather and run a single wire to the battery from there?

I read a post where David said to run the power for the head unit from the the location on the master + switch the amps use.

Does the "constant 12v wire" to the head unit go on the hot side of that switch, and the switched wire on on the switched side?

Is it better to use the amp "turn on wire" from the head unit, or to just wire all of the amp remote wires directly to the switch, ad not using the "turn on wire"?

Anyone else getting a "pop pop pop" noise in there speakers when the ignition key is turned on?

Thank you for your input!

Malibu Stereo config 2012.doc

Edited May 1, 2012 by WakesetterE

[Steve B.]

I need this question answered too. I"m going to start a complete new stereo install next week.

Steve B.

[liljohn]

Most of us run our power and ground for all of our stereo equipment from the same place. meaning in my situation I run everything off the distribution blocks. This gives me single wire runs to the batteries. I have a switch under the dash that turns everything on and off thru a relay. I did not run anything thru the perk switch. Distort blocks go battery direct. There's no noise ,no pops ,no issues.

[Deephaven]

I run everything off the distribution blocks

Definitely the best way.

As for your other question regarding the remote turn on, that can run from the headunit since the headunit power will come from the distro block.

If you still want switched power to your headunit from the key then you will need to add a relay so that the ignition power will just connect the power from the distro block.

*remember to fuse all wires that are smaller than the incoming wire on the distro right near the distro.

[shawndoggy]

I have a single run to one of these:

[JoeMama]

One type of pop when turn ignition on is due to excessive current causing voltage drop on battery which resets the amplifier and stereo. So when you turn the engine on, see if the head unit radio gets reset. If it does then a solution is to add a second battery or replace the one battery with a much bigger battery. Then there wont be much of a voltage drop and the stereo/amps wont get reset.

[WakesetterE]

Thanks to all for your assistance! This site is the best and a true resource for all. Its for reasons just like this I send my contribution to keep this site going. You cant buy the combined experience all of we boat owners have here at this site!

After countless hours (too many to admit!) I was able to defeat the popping and hissing in the stereo that that defeated me for so long. Like many have now said, I hooked all the positive leads together to a distribution block ($14 Academy), ran a wire from there to the battery. Did the same with the negative wires from the head unit and line driver. I made sure there were no other connections except from this source. Noise is GONE!! :clap: :clap:

Its really hard to believe that’s all there was to it. I had the head unit grounded to the factory distribution block(bad idea), and the line drive with its own wire direct to the battery ground. Even with the fuse pulled from the head unit and the iPod inputting the signal to the line driver, the popping and noise was still there and terrible...because the ground loop was still there. The noise was really loud, and i was convinced the line driver was generating the noise. In fact, if I removed the line driver, the noise was completely gone. I rationalized this indicated that the line driver was bad or making the noise, when i was really just setting up an unintentional ground loop. Since I was adding a direct wire to the battery ground, it seemed I couldn’t be setting up a ground loop. But, it was the head unit ground that was the problem as soon as I put another ground in the system. Seems obvious now, but for hours and hours I tried countless other things like new RCA cables, rerouting and moving wires, etc, etc... Heck, I laid under the dash while my wife drove the boat around the lake as I moved wires and the line driver around trying to find a way to quiet the noise. (that may have looked weird)

David’s old post really helped me a lot when he said "draw the power and ground from a single source". I appreciate everyone’s help, another issue put to bed with victory!

[shawndoggy]

So here's a question for you 'E... I noticed that your diagram says you have all of your xovers set at 150hz (highpass for boats and towers, lowpass for sub). That is a lot higher than I've ever tried. Why did you go that high?

(Legit question -- I'm no expert!)

[Earmark Marine]

The true noise devil is any resistance difference or voltage potential between the components specifically in the signal path. All supplies and grounds will carry some degree of variations/spikes/ripple. So when there is a different reference the voltage will attempt to correct via whatever path, no matter how resistive, that circumvents the intended isolation. This path often happens to be the connecting RCA ground shield which was actully intended to protect the signal from radiated noise. Now you have turned the protective shield into a noise transmitter. Under those conditions the smallest amount of cuurent flow translates to massive noise. Fix any external difference in voltage potential and you have usually fixed the noise.

David

[WakesetterE]

Great question! With my sony factory 6" speakers, i had to cross them about 200 hz or they would distort at high volume with 100 watts each. (they were rated to 60 watts rms) To me, I was lacking any mid bass, and the cabin speakers sounded thin. When I replaced them with the wet sounds speakers, it was very apparent the wet sounds speakers could handle more exstention and play lower while not distorting. With 100 watts RMS they play clean.

So I lowered the cross over point to 150 to get a little more low end into the cabin speakers. It made a huge differance and sounds much smoother. I'm really a believer in the wetsounds speakers, as I was somehwhat a skeptic at first it could make the differance it did. (I want 4 more! )

The 68 pound 15" sub and its 4 cu foot box with 1500 watts makes some bass. When I first hooked it up, I didnt realize my head unit filtered the low end out of the outputs as a default setting, and sent that range to the sub out lead. So, I was sending an output from the deck to the sub amp that had 50hz and below cut out, then my cross over in the amp was cutting 100 and above, as it was intially set up at 100 hz. That resulted in a sub that sounded so crazy boomy, and bad I thought I had built the box wrong! It was really bad sounding, I nearly started over! After getting full range to the sub amp, I found raising the xover to 150 hz allowed the big 15 to play a wider range and still not sound boomy. My goal was to try and establish a seemless integration of sub and cabin speakers so when playing the system at very high levals it would sound better than just loud. The tuning of the sub box also has a lot to do with where it crosses best. If I had more time and money I would add about four 8" drivers to add more punch, and four more 6" cabin speakers to even the sound out. However, for now, it cranks pretty good.

[Bobby Light]

I need to see this 4 cu ft box you did, that's a big box for that boat. Have you tried your cabin speakers at 90-110 hz? 150 is awful high, higher than tower speakers even get crossed over at.

Edited May 3, 2012 by Bobby Light

[WakesetterE]

I havent tried any lower yet, but I will. Here are some photos of the sub. I have it out chasing the noise issues. 3/4 particle wood, sprayed with bed liner inside and out. The port is removable to allow it to fit in place under the drivers dash. Port faces the driver on the right side of the box. Fit is very tight all the way around.

Edited May 3, 2012 by WakesetterE

[WakesetterE]

Where do you think the best place to cross the pro 485's are?

[Bobby Light]

Now that's thinking outside the box, nice. Just as a general place to start try.

Cabin - HP 90-100 hz

Tower - HP 100-110 hz

Sub - LP 80-95 hz

Tweek it to your liking and listening levels.

[WakesetterE]

I'll give it a shot, thanks!

[Bobby Light]

Also since you have a ported box get a tone generator app and run a sweep on your box to set your infrasonic filter and knock out frequencies below tuning point. You'll gain some output and let the amp work less.

[WakesetterE]

My tone generator apps dont work well at low frequencys. I may need an external mike....? The subharmonic is now set at 33hz on the eq, which can be adjusted....

[Bobby Light]

No external mike needed I just plug my phone into source control and go from there. If you have an android I can suggest an app.

[WakesetterE]

I do, an HTC. Which app?

[Deephaven]

I like funcgen for that, but there are plenty others.

[Bobby Light]

I do, an HTC. Which app?

I use a free app called Waveform Generator Lite.

[MystiikVLX]

Most of us run our power and ground for all of our stereo equipment from the same place. meaning in my situation I run everything off the distribution blocks. This gives me single wire runs to the batteries. I have a switch under the dash that turns everything on and off thru a relay. I did not run anything thru the perk switch. Distort blocks go battery direct. There's no noise ,no pops ,no issues.

What is this switch you use to turn off/on your system? Any info much appreciated.

[40oz]

+1 for distribution blocks. I now have everything going straight to the battery and problem solved.

[scvlx]

This thread also solved my popping problems (turning ignition on and also nav lights). I will be a paid member soon, great resource.

[WakesetterE]

Ok, I started this post may 2012. I had several problems with noise in my stereo system. I installed "home run wire" to the deck, pre-amp, and EQ direct from the power supply and celebrated when the noise was gone. I spent a long time putting it all back togeather and on the next trip to the lake the noise was back.

I thought the deck was bad, the pre-amp, the wiring...the ignition switch, a amp, something! I replaced all of the cables, wiring, and started working backwards from the amps with a Ipod as a pre amp...no noise.

So it must be the deck....I disconnected the deck completely, the pop,pop,pop,with hiss was still there with the key on. I removed every stereo system wire from the battery, wired every positive and negative to a seperate 12v battery resulting in the stereo, amps, pre-amps and EQ all wired alone.I turn the key on and still the noise remained. It has to be radiated... I took the dash apart, found the tranducer wire where it connected to the depth finder(fatter coax, black). When I disconnected the transducer wire, the noise was gone. I checked the transducer wire routing and it was as far away as possible from the deck and other stereo wiring.

So, now that I know the factory depth finder is causing the noise, does this sound like a bad transducer or bad depth finder, or ? What have others done to correct this. Of course I can leave it disconnected, but its nice to have a working depth finder. Have the stereo gods had this issue before?