Speaker Fuzz!

[Jeff T]

Ok, so I completed the install of the 420 (well sort of). My friend and I worked efficiently with the time available to us over the last 2 nights (about 2.5 per night) to get everything in. We took our time and tried to do everything right.

When I fired it up, the very first thing we noticed was the fuzz coming from the speakers. At first, I thought it was just coming from the tower speakers, but I was wrong. The tower speakers were more noticeable than the deck speakers, so you had to stick your ear to a deck speaker to hear it.

I turned the volume all the way down to zero and turned the volume down on the 420...still had fuzz. We double checked and adjusted the RCAs, etc. and still had fuzz. Re-routed the power/ground runs for the 420...still had fuzz. I turned the gains down on the tower speaker amp as low as they would go and it cut the fuzz down considerably, but not completely. The gains were not that high to begin with (about half way). Turned the gains back up to where they were and fuzz went back up accordingly.

We then unhooked the 420 and put everything back as it was to see if we originally had fuzz and just didn't remember (but I knew this was impossible). Surprisingly, we still had fuzz, but at a MUCH MUCH lower level. So the fuzz was always there, but i apparently just didn't notice it.

So, my hypothesis is that I have noise in my system and the 420 just amplified it in a big way. I'm not positive what's causing it.

A: Is this the "noise" created by not having the head unit powered and grounded directly to the battery?
B: Is this the type of interference noise created by power runs too close to speaker wire or RCAs?

Sigh. After two long nights, lots of scrapes, and $$, I feel quite defeated.

Any advice is appreciated. Off to lick my wounds now...

[Tanner]

Yes your head unit needs to be grounded directly to the battery. In fact where in the boat do you have it grounded if not there?

Then next thing, do you have a dedicated stereo battery? If so, pull everything off of there that's not your stereo. Power and grounds running along your RCA's can and will introduce noise. Definately want to have high quality RCA's. Good luck.

[Jeff T]

Yes your head unit needs to be grounded directly to the battery. In fact where in the boat do you have it grounded if not there?

The HU grounding/power is the same as it was when it left the factory. Where that is or how to change it...I have no idea.

Then next thing, do you have a dedicated stereo battery? If so, pull everything off of there that's not your stereo.

I have the EDIB from Tige with 1 deep and 1 starter. I have not re-arranged what pulls from each battery. Everything is set how it came from the factory. The only additions are: My 0 gauge ground/power that goes to my dist blocks (for amps) and the 18 gauge ground/power to my 420. Both pull off of deep cycle.

Power and grounds running along your RCA's can and will introduce noise.

What kind of noise is produced by this? If I have a section is a matter of inches where the RCAs and/or Speaker wire contact or come close to contacting ground/power, will noise be created or is noise generally created by longer lenghts?

[QUOTE=Tanner;171207]I did my very best to prevent any RCAs running parallel to power/ground cables. There are a limited number of places where you can pass cables through compartments.

Definately want to have high quality RCA's

Not a problem. I have Stinger Pro3 series cables. They are quite nice and not cheap.

[chpthril]

Jeff,

Dont worry about where the H/U power & ground come from. Just run a new power and ground from the head unit to the dist blocks or back to the battery.

H/U gnd is black, powers are red and a yellow.

[Jeff T]

I should clarify one thing: I'm trying to understand what would create a fuzz type of noise. I fully realize there are 2 main causes of noise: 1: not having the HU grounded/powered at batteries (or same place as reast of stereo) and 2: Close proximity of RCAs to Ground/Power cables. I just don't know what kind of noise either of these can produce and if this "fuzz" noise falls into either category.

[Jeff T]

Jeff,

Dont worry about where the H/U power & ground come from. Just run a new power and ground from the head unit to the dist blocks or back to the battery.

H/U gnd is black, powers are red and a yellow.

Ok. You posted yesterday about the little fan on the back of the HU. I checked and I do have it. If I just run ground and power directly back to the battery, will this fan run down the batteries?

Lastly, (and I'm asking this because I can't look at my boat until i get home this evening), is the ground/power plugged into the HU via a wiring harness? Am I supposed to just clip these wires and re-route out of the harness to battery, leaving the other length hanging (with a cap on it of course)?

[chpthril]

Basically, audio equipment is 1 big antenna, and it can and will pick up stray electrical "noise" and that is what you are hearing. The noise is just regular old current flowing through other wires in the boat. You cant stop the noise, but you can do thing, such as we are discussing here, to prevent the stereo from picking it up.

[chpthril]

Ok. You posted yesterday about the little fan on the back of the HU. I checked and I do have it. If I just run ground and power directly back to the battery, will this fan run down the batteries?

Lastly, (and I'm asking this because I can't look at my boat until i get home this evening), is the ground/power plugged into the HU via a wiring harness? Am I supposed to just clip these wires and re-route out of the harness to battery, leaving the other length hanging (with a cap on it of course)?

Pretty much, yes. The H/U has it's own harness with a white square plug that goes into the back of the radio, and wires that splice into the boat's harness. There should be 2 white plastic in-line fuse holders that are part of the H/U's harness. Clip those wires AFTER the fuses and then run your wires to the new source.

[dogbert]

I had the same issue. It was easily solved with a ground loop isolator between the head unit and the amps. Now it's crystal clear.

As chpthril mentioned, your stereo will pick up noise from lots of places. It's always a good idea to have your stereo components to get their power and ground from the same place, but that's not always possible. I like the fact that my H/U is wired to the ignition switch so my stereo turns off when I start the engine.

So, what you could try is picking up a couple of ground loop isolators (Best Buy carries them) and put them in between your H/U and your 420. That should fix your problem.

[Jeff T]

Pretty much, yes. The H/U has it's own harness with a white square plug that goes into the back of the radio, and wires that splice into the boat's harness. There should be 2 white plastic in-line fuse holders that are part of the H/U's harness. Clip those wires AFTER the fuses and then run your wires to the new source.

And I leave the other end just hanging with some sort of cap on it so I can reattach later if needed?

[Jeff T]

I had the same issue. It was easily solved with a ground loop isolator between the head unit and the amps. Now it's crystal clear.

As chpthril mentioned, your stereo will pick up noise from lots of places. It's always a good idea to have your stereo components to get their power and ground from the same place, but that's not always possible. I like the fact that my H/U is wired to the ignition switch so my stereo turns off when I start the engine.

So, what you could try is picking up a couple of ground loop isolators (Best Buy carries them) and put them in between your H/U and your 420. That should fix your problem.

Ok, that is interesting. Do RCAs plug into this ground loop iso? Would I need 1 or 2 isos? There is only 1 set of RCAs from the HU to the 420.

[dogbert]

Ok, that is interesting. Do RCAs plug into this ground loop iso? Would I need 1 or 2 isos? There is only 1 set of RCAs from the HU to the 420.

Yes, they do. If you only have one set of RCAs going from the HU to the 420, you'll only need one. It also has a ground wire that you need to attach to the ground on the 420 and the ground on the H/U. I have 2 because I have my tower amp on my front channels and my in boat amps on my rear channel. I don't have one of those fancy 420s.....yet

BTW, you should also try your speakers while your engine is running. I found that I also had some whining coming through from the engine to my speakers that was more pronounced once I switched them from my H/U to the amps.

Also, my boat came with just the stock H/U and in boat speakers. I added all the amps and tower speakers. I did run a separate ground/power from the batteries (in the back of the boat) to the storage area where I have my amps.

[chpthril]

And I leave the other end just hanging with some sort of cap on it so I can reattach later if needed?

Just tape them off and tuck them into the harness.

[Jeff T]

Yes, they do. If you only have one set of RCAs going from the HU to the 420, you'll only need one. It also has a ground wire that you need to attach to the ground on the 420 and the ground on the H/U. I have 2 because I have my tower amp on my front channels and my in boat amps on my rear channel. I don't have one of those fancy 420s.....yet

Just tap in to the 420 power/ground, or run seperate back to the battery?

[Jeff T]

Just tape them off and tuck them into the harness.

Thanks. You mentioned in a post yesterday that I may have an issue with the fan on the back. If I just run new ground and power back to the battery, the fan will run as long as the HU is turned on or all the time? Can you clarify what you meant in that post?