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arny7 · 01-15-2009, 06:34 AM

2007 monaco Dpl Speakers humming noise How do I fix

danes-on-tour · 01-15-2009, 07:00 AM

Hi arny7

Your problem is shared by most Monaco Diplomat owners it would seem.

Go to "Find" and put in the keyword "humming" and you will find a number of treads covering this issue. Here is one of them.

Our can also do what I did: Take out the factory installed system and put in another one of your choice. Here is a picture of our installation.

We enjoy the benefits of our modification every day and it became even better when we also changed the ceiling speakers. The sound is now second to none.

Sixpack98 · 01-15-2009, 03:32 PM

While the factory speakers are really poor quality I doubt that the speakers are the culprit. They are at the end of the line and the hum was introduced way before them. Probably in the RCA or Magnadyne power supply or the audio inputs.
The inverter/converter can introduce quite a bit of hum on both the 120v and 12v system. You can filter both systems and that can, in most cases, reduce the hum. However, this can be expensive to actually achieve. Trying to select a suitable power filter assembly can be hit or miss unless you hire someone with the right equipment to better understand what noise component is causing the hum. The RCA stereo that is standard equipment has a horrible power supply and does not do a good job of reducing noise. I replaced the RCA with a decent Sony receiver which had good filtering and no longer hear any hum through the speakers. I noticed that if I turn off the 12v converter the noise went away. Turning off the inverter also helps and you don't need it on if you are on shore power. Also, some have had some success with ground loop isolators on the audio inputs. They appear to help but they also can degrade sound if not chosen and integrated correctly.
Monaco introduced a "solution" after many, many complaints. Problem was, the cure was worse than the disease.

mark

danes-on-tour · 01-15-2009, 03:49 PM

Quote:

Originally posted by Sixpack98:
While the factory speakers are really poor quality I doubt that the speakers are the culprit. They are at the end of the line and the hum was introduced way before them.

Monaco introduced a "solution" after many, many complaints. Problem was, the cure was worse than the disease.

mark

Sixpack98 is right and I couldn't agree more. I trying to catch him our on something where I can disagree but it won't be this time either.

WayneLee · 01-16-2009, 05:34 AM

This is a well known issue for almost all of Monaco's line. Moncaco has issued several service bulletins releated to the problem and they have a "kit" that is suppose to fix it. I had mine done while it was still on warranty - in fact, it took 3 trips back to the dealer to get it right. Now, I don't have any "hum", but I have lost some functionality in the system.

CoolJourney · 01-16-2009, 07:19 AM

Quote:

Originally posted by Sixpack98:
I noticed that if I turn off the 12v converter the noise went away.
mark

I have the speaker hum when the inverter is on and I am not on shore power. I do not know how to turn off the converter (and wasn't even sure I had one) on my 2007 Diplomat. Can you provide any details on how to turn off the converter?

Thanks.
Bill

LewF · 01-17-2009, 11:44 AM

You need a "ground loop isolator" installed in the audio input lines to the amplifier. You can get the one I used at Amazon for about $35.00 This is a very simple problem to fix. The link to the place to buy is - http://www.amazon.com/Xitel-GL...f=dp_cp_ob_e_title_1 I hope this get you there, if not search on "ground loop isolator" and Xitel. This is a very common problem with home entertainment systems and I am surprised there is so much bad information out here about how to fix it. Good luck.

Sixpack98 · 01-17-2009, 05:04 PM

Quote:

Originally posted by LewF:
You need a "ground loop isolator" installed in the audio input lines to the amplifier. You can get the one I used at Amazon for about $35.00 This is a very simple problem to fix. The link to the place to buy is - http://www.amazon.com/Xitel-GL...f=dp_cp_ob_e_title_1 I hope this get you there, if not search on "ground loop isolator" and Xitel. This is a very common problem with home entertainment systems and I am surprised there is so much bad information out here about how to fix it. Good luck.

Ground loop isolators are not needed in a properly designed audio system whether in and RV, car or home environment. The problem is poor system integration and design by the installers. A ground loop isolator is a band aid for poorly installed system and degrades the audio quality. The solution is a single ground reference eliminates differences in ground voltage differences. Also, in an RV hum and noise can be introduced from other sources which a ground loop isolator will not help. Implying that a ground loop isolator will solve his problem without knowing where the hum or noise is coming from is bad information.

LewF · 01-18-2009, 03:53 AM

Sixpack98

In theory you are correct but here are some things to consider. The hum is probably a 60 cycle hum from the AC system and is caused by two slightly different potential systems/circuits trying to equalize themselves and impressing a signal on the audio feed to the amplifyer. If designed properly this would not happen but in the complicated (and confusing) electrical circuit design of my coach I am not able to figure out how to eliminate this design flaw. The 60 cycle signal in my coach was impressed on the audio signal to the amplifier and then input to the speakers and could be heard whether an audio component was present or not (radio on or not). I could have tried to research and redesign the circuits to eliminate the potential imbalance but that is a complex task with little payback for the time and money spent. The ground loop isolator is a very common method of fixing problems like this (that is why so many companies make them) and it worked on my coach. I have been puttering with things electrical and electronic for a good deal of my adult life and find that sometimes an inductive or capacitive signal isolating circuit is the only solution to eliminate noise generated by stray RF or other cyclical signals - 60 Hz, 400Hz, etc.

For arny7, you have to determine if your problem is the same as many other Monaco built coaches of your vintage and then if it is then this solution will work for very little cost. Monaco has not been able to design a system that eliminates the problem after at least two false starts so it appears to be a difficult design problem that can be solved for about $35.00.

Good luck.

Sixpack98 · 01-18-2009, 03:39 PM

Understand what you are saying and agree but you are assuming the OP problem is with the AC and not the DC system. There is an issue with 60hz hum coming from the Inverter/converter that could be causing the problem. Monaco's solution was an absolute joke and a sledge hammer approach that ended us as a fiasco. My '06 Endeavor does not have the same set up as the '07 and above but I doubt if they integrated the '07's any better than the '06's. While I do not have hum introduced on the AC side I certainly did on the DC side. Some of the had the Magnadyne DVD player which was DC powered and hum was introduced via the DC supply and also ground loops. Ground loop isolators did fix the problem but did so by filtering out the 60 hz hum as well as isolated the desparate grounds. Hense, my band aid approach to systems integration