Printable View
I replaced my stock ZX200.4 with a ZXM700.5 and after installation I tested everything and it was perfect. That was until I started the engine!
I am getting a really high pitched sound coming our of my speakers while playing music with the engine on.
With the engine off, its perfect.
Any idea what would cause this problem?
I had the same issue. My HU ground was connected to the starting battery neg and my amp's ground was connected to my stereo battery neg. I moved the HU ground to the the stereo batt ground and the noise went away. So check that every component in your stereo system is connected to the same battery, both pos and neg, and the noise should go away.Quote:
Originally Posted by deafgoose
Al is right on with his suggestion. You are dealing with alternator whine, which is simply electrical interference. If you still have some of it after checking your ground, you can get ground loop filters that go inline with your RCA cables. They will help a great deal, too.
deafgoose,
Try and avoid using a ground loop isolator until the final solution because it still leaves the gound or supply loop intact.
First, check that your input gains are not too high on the amplifier. Good tuning often resolves this especially if this amplifier is wired the same as the previous amplifer.
Next, if you have dual batteries then make sure that no components are wired battery-direct. Everything should come from the dual battery switch common (output, not ground) post. This automatically eliminates a potential supply loop. If using a VSR then the scheme may be different in which case everything audio goes to the same battery.
Next, sometimes the long route via the factory harness that supplies the HU introduces too much resistance. A new 14-ga to 12-ga B+ and ground can be run either to the same supply source or to the terminals, or closest to the terminals, of your largest amplifier or in this case the new amplifier. To close the noise inducing loop, and technically speaking, having the least potential between components in the signal path is more important than the supply path. However, if the amplifier is in very close proximity to the battery then this distinction is less relevant.
Next, verify if the amplifier has a high and low input selection switch and make sure its set to the correct setting.
Its always possible that a long and coincidental routing of the RCA cables and power cables could induce noise but its very improbable.
A single shorted speaker wire, especially after a crossover series capacitor where its difficult to measure, can induce noise into all channels. You can simply remove all speakers and add one at a time until the noise re-appears.
Those are the basics. Its usually a very quick and easy diagnosis.
David
Earmark Marine
I had this before I switched head units. Run an 18awg wore from HU ground to Amp negative. Problem solved.
Hmm.. Interesting.
Well my original amp had both the amp and HU grounded to the negative terminal on the battery.
You guys are talking about "stereo battery ground" and "starting battery ground" but I only have one battery. Where should I ground the HU?
My input gains are maxed out so maybe thats the problem.
Id start right there. Id say set them about the 11 oclock position.Quote:
Originally Posted by deafgoose
Update: I turned down the input gains to the 11 o'clock position and it made absolutely no difference.Quote:
Originally Posted by MLA
Where else can I ground the amp besides the negative terminal on my battery?
Try a new set of RCA cables. Just run them direct from the source to the amp. Do not bundle them up like a permanent install, just lay them across from A to B and try that.
Hey 'Goose-
A few questions for ya:
1. DId you use the power wiring that was there already, (200.4) or did you install new 4ga wire for the 700.5?
2. Where is your head unit power wiring connected?
I ask these two questions first since the noise you are getting is associated with a voltage potential difference between the head unit and the amp. Using the too-small stock power wiring can cause this. Additionally, we want to take steps to make sure the head unit is at the same voltage potential as the amp. This often gives us the opportunity to try the very simple re-wire job that David already pointed out, specifically taking your three head unit power wires and connecting them directly to the amp:
Your yellow power wire goes straight to the amp's B+ terminal. Your red power wire also goes to the amp's B+ terminal, but through a switch o relay of some sort that will allow the stereo to be turned on and off. Finally the radio's black power wire goes to the amplifiers negative terminal.
90% of the time, this simple head unit re-wire will remove the4 whine and noise you describe.
The fix will be easy, but you need to take a systematic approach. One thing at a time.... Replacing the RCA cables might do the trick, so don;t rule that out. But, check your power wiring first, then move down the chain, checkign things one step at a time. It can be intimidating for the average Joe, kind like looking under the hood of a car, but it really is very simple and straaight-forward.
Let us know!
Phil
Kicker
I have the same problem with my KMT6s. They are pushed by the ZXM450.2. My cabins and sub are being pushed by the ZXM700.5. They are both ground to the same point. The only difference is that I have a PAC volume control to control the volume of the towers. I’m pretty sure the problem lies with the PAC. The installer suggested to try “jiggling” the RCAs on the back of the PAC…yeah…ummm that didn’t fix it. If the PAC is all the way up or down and the motor is on there is no whine. However if the level is anywhere between there is. I’m sure it has something to do with how the RCAs were run for the PAC but I don’t see a power wire or anything like that near the run that would usually be the cause of this. Oh well I’ll figure it out eventually.
Alright. I am just about to tackle this project today.
Where else can I ground my amp other than the negative battery terminal?
I was having a look inside the compartment and noticed the 4 studs with nuts for the wakeboard tower. Would that be an apropriate location for a ground?
Any help is greatly appreciated.
Deaf, since you only have one battery, connect your amp ground directly to the neg post on your battery using at least 4 awg cable.
That is how I currently have it connected and I have a ground loop. I need to find an alternative ground for my amp.Quote:
Originally Posted by cab13367
Update: grounding the amp to the tower bolts did not work. The stereo won't even play now, even with just the radio playing.
Did you try grounding your HU to your amp's neg lug?Quote:
Originally Posted by deafgoose
That may work but would require me to gut my entire wirin harness to simply "try".
I know for a fact I would solve my problem if only I could find a decent ground point for my amp.
Not sure what your logic is here. There can be no better ground point than the battery's neg post. Or am I mission something?Quote:
Originally Posted by deafgoose
You don't have to gut your harness. I just cut my HU ground wire after the harness, butt spliced in an 18 awg cable, and ran it straight to the batt neg.
I think that in your case, it might not be a ground issue.
is the whine there with the amp gains turned all the down? is it a new amp or a refurbed amp?
The amp is brand new. There was no high pitched sound unless the engine was running.Quote:
Originally Posted by jmvotto
When I turn the key to "run" position, I get the high pitched sound for 10sec and it stops. When I turn the engine on the there is a whine that is added to that high pitched sound. ANNOYING! :mad:
I ended up grounding the head unit to the amp and its gone. :)
I really appreciate your help guys. Forums really help for times like these.
Glad you got it figured out. Sounds like it was picking up noise from the fuel pump. Mine is doing that same thing but I haven't had time to troubleshoot it. ALL my stereo gear is grounded to the stereo battery neg post so I'm not sure where I'm picking up the hiss. I can't hear it once the stereo is turned up so not too concerned about it.
i have the same issue. its a real low volume hiss and you can only hear it when the volume is all the way down or very very lowQuote:
Originally Posted by cab13367
Yeah, very annoying when it goes quiet between songs.Quote:
Originally Posted by rdlangston13
Your solution was right there on page 1 goose.... :DQuote:
Originally Posted by philwsailz
Phil
Kicker
Yep. I was just too scared to try it.Quote:
Originally Posted by philwsailz
Once cab was suggesting the same thing, I figured I gotta try it.
Ok, this is just wrong. Phil is an audio engineer who works for a respected mobile audio company. I have no formal audio training whatsover, just on the job training, so to speak, doing my own installs. And reading stuff on the internet :)Quote:
Originally Posted by deafgoose
So please, next time, take Phil's advice!
Al
I have the same issue. So you grounded your head unit to the amp? I have two batteries, and have everything grounded (both amps) to the same battery. The only thing that I don't have is the power lead from the speaker switch powered from the stereo battery. Wonder if this might help. The whine isn't horrible, but, I can hear it... I'm probably the only one who can, but still.
I was going back and forth with Phil last year about this, and got the noise reduced. Wonder if that power would be the next thing to try.
Yep. That simple. I grounded the head unit to the negative on my amp and it solved my problem.Quote:
Originally Posted by squeeg333
Speaker switch?Quote:
Originally Posted by squeeg333
I find it funny that 'goose thought moving the head unit ground was hard, but he was fishing the amp's negative wire all over the place for a ground other than at the battery.... fun stuff....Quote:
Originally Posted by cab13367
No harm 'goose, just having fun. I am SO glad you got it figured out!
You guys have a great day, and please send us rain here in north central Oklahoma. our lakes are dry and we need rain!
Phil
Kicker
Sorry Al, I mean the stereo switch, on the dash.
I have a 2011 LSV with the same issue. Hopefully changing the HU wiring will eliminate the hum. It drives me nuts!!!!
I recently did this to my boat. It worked for me.Quote:
Originally Posted by jikemones
I also added a +wire to the HU just for good measure since I was under there working. Just the constant +, not the switched +.