PITA Hum

[rfoster]

Last night is the first night in a while for us to dry camp.

I have a PITA hum coming thru the rear overhead Bose Speakers when the bus is parked for the nite, Gen is off and we are running on batterys. Any suggestion as to what is causing this?

Is it that the Bose System doesn't like the sine wave coming out of the inverters now? Is there such thing as a filter for the power source?

Maybe there is too much reflection of bling and it is making a noise?

I had to fire up the generator to eliminate it so I could enter dreamland. It is that annoying.

I am in the coach now and my next project is to get rid of that hum when I get home.

Thanks in advance to all you electronic gurus for clues

[dale farley]

I think it is your inverters.

[mike kerley]

Yep. Its the inverters! We had the same problem in our Beaver years ago. The fix is not an easy one. You must "rebuild" the electric current feeding the Bose. Transformers needed to do this are heavy and get hot. Bose simply does not like the modified sine wave (or square wave) that most inverters produce. Eventually, I gave up and installed a different sound system. Cheaper than a new inverter!

[truk4u]

King,

Can't you kill the power source (fuse or breaker) to the Bose system while your trying to get to dreamland?

[JIM CHALOUPKA]

The best one is to teach it the words, you know no humming. ;):D

Next you could turn off the unit.

We get the same sound plugged into 120v ac at home with the surround sound. Can't stand surround sound.

JIM

[dalej]

Roger, I would think that your coach is new enough that your inverters are the pure sine wave type.

I had to install a line conditioner when I installed our Bose. It cost me about 500 back in the early 90's.

[merle&louise]

Roger,

I had the same problem; it was the surround sound. The volume on the surround sound was too high, when I turned it down the humming went away. Simple fix!:D

[Jon Wehrenberg]

Roger, The best part of all this is I know you know I am spring loaded to break your chops. But I won't right now. But I remember all this stuff. I'm still bitter over having the King of Bling award ripped from my hands.

Some guys create mole hills, some guys let the sheep loose, some guys get blow up dolls. Hmmmm, what will your reward be?

[sawdust_128]

Pink Earmuffs??

[JIM KELLER]

Roger, Our Bose does the same thing if the volume is turned up too high at the switching center.

[MangoMike]

Fast Roger,

Reverting back to this may solve your problem.

I think Jon has an extra one in his spare parts bin.

3864

mm

[Joe Cannarozzi]

You could drown it out with some singing of your own.

[merle&louise]

Or maybe Mel Torme would provide you with one of his CDs of his greatest hits!:D

[Jon Wehrenberg]

Roger,

I'm not going to pick on you. Everybody else has done it for me.

I like Jim Keller's comment. Just turn down the volume. If he does a road service call for a flat tire I'll bet he tells the car owner to turn the tire over because it is only flat on the bottom.

Mango is wrong. I do not have one in my spare parts. It is upstairs in the living room and I'm using it.

Joe C was being downright cruel. Santa will be bringing him coal for his stocking.

And what's with Tuga breaking your chops? Or Mel's? Do they even have a sound system in a Newell?

[JIM CHALOUPKA]

Roger, when you go to bed, turn it off and make your own music. :D

JIM

[merle&louise]

Surround sound is standard in a Newell because when the slides are open there is so much open area the sound from the TV needs to be amplified:D

Roger can identify with that situation when his slides are open! Right King!

[truk4u]

A-1 can't give surround sound advise, he's still dreaming of stereo!:p

[lewpopp]

You could give Roger the "Hummer Award". Hmmm, come to think of it, there used to be a gal at home we called the "hummer". Wonder why?

[garyde]

Sometimes my front TV monitor will make a high pitched buzz, but it is intermitant, and I have not looked into it as of yet. The Bose system in the front and the bose system in the back do not make any noise when turned off. Maybe a simple filter from Radio Shack for your 120 volt cord recepticle for the Bose would solve that problem.
The wolfer also has a 120 volt plug in so you should buy a filter for it as well.

[rfoster]

Hey (with a big grin) thanks for all those responses. Just think what a noobie imagines when he reads thru this post. He is gonna get pretty excited.

Truk, A1 still listens to AM. I know.

Mike Kerley, you are probably right --- unfortunately.

This is occuring with the Bose off and the inverters are inverting. The volume is down to zip. Another potential problem is the Bose system itself. I will have to do as Truk suggested and kill the power to the Bose. On this CC they made it difficult to perform a simple task such as umplugging the surround system in that the breaker is in the bay outside and the plug is in a compartment in the closet that is a pain to get too. It was 29 with freeezing rain and a bit breezy plus it was past my bedtime.

Dale what is a line conditioner? and were did you get it? Radio Shack?

Mango sometimes I wished I had one of those. I still don't know how to get all the video / audio crap to work like I want it to on this coach.

At least when I fart it doesn't turn the Tv to channel 4.

Jim K. remember in Mobile that the display was not working on the Bose, still doesn't work. Could be related to that. It is just dying a slow death.

But -but-but My Slides still work, the surround sound still works up front, the sheet metal is still glued on, and the windows ain't broke, but I ain't bragging,

I believe that global warming is over, the election is finally over, gas and diesel are cheaper than they have been in a while, and the drought in the Southeast is about over, just don't turn on the TV and life is good.

[phorner]

Just for what it's worth, our Bose Lifestyle surround sound system crapped out a couple of months ago. While listening to the FM radio, there was suddenly a nasty hum followed quickly by silence :eek:

Our sub-woofer is located under the sofa and plugged into the same circuit as the electric blinds, and I found that the fuses on the blind controllers were both blown, which led me to believe that we had experienced some sort of electrical surge which had also damaged the Bose system.

Anyway, a quick call to Bose and they have a policy of re-building the unit for a flat charge. So I shipped both the sub-woofer and tuner/cd player sections to them and for $240,( including return shipping) they inspected and re-built everything. Also up-graded any software/firmware as necessary and comes with a 1 year warranty.

Works perfectly now.

I thought it was a bargain :)

[rfoster]

Paul:

That is news I can use. When I get home tonight I will get busy and and remove the receiver to send it to Bose.l Even if that is not the root of the hum, I still need to get the display working.

Thanks again- I needed to know that.

[rfoster]

With some free time and a mission to find the hum- I am pleased to announce that the hum in my bus is gone! It turns out that after unplugging the power to the Bose Lifestyle 30 2 zone surround sound that I still was getting the hum thru the rear speakers. (That took a while just to unplug them as they are buried in a compartment that has be removed just to get to the backside of the receiver) How could this be? So I unplugged what I thought was all the speaker wires (rca outputs) and still had the hum. So I continued to unplug smaller wires that were multiple conductors turning out to be the zone controlled speakers and when I unplugged them the hum got louder. Go figure. I unplugged all of them.

So I started plugging the wires back up (with a bit of disgust) and accidentally plugged the zones in opposite of their original position- Hum stoppped and was gone. Zone 1 became Zone 2 and Zone 2 became Zone 1. And it all works now with no hum.

So someone had been into the spaghetti bowl of wire before me and plugged them up wrong or for whatever reason a hum was created with inverter power. The Bose Surround has the separate powered bass speaker and there must have been some nasty feedback getting to the speakers.

It may turn out to be an inverter problem that creates the hum thru the speakers. But for now its gone and I am a happy dry camper! Silence is golden.

This does not qualify me to give advice on Bose Systems or Space Shuttle.

[lewpopp]

Roger, the next time you take the bus out go very slowly at first. They reversed wires might be connected to the steering. Just a precaution.