Riddle me this electronic experts

[powerboatr]

Last night whilst wife was vacuuming with the built in dirt devil, all was good
then as she approached the cockpit we started getting feedback like you have never heard.. like a microphone was open and you were the opening band for def leppard
we are talking dog howling and ear piercing feedback, it wasn't coming from the speakers as far as i could tell
unplugged the attachment and it still was there. got painful the closer she got to the steps

any ideas on wise persons of electronics/sound knowledge

[TXiceman]

Feedback on what? Was it through the cockpit radio or was it through the surround sound speakers? Was the radio on or off? Have you used this vacuum in this area previously?

Tell us a bit about the equipment? If you were getting a feedback like sound, it had to be from the speakers. Are you sure it was not a resonance set up by the vacuum in the hose/piping or the vacuum housing?

[RVDude]

Yep - that Devil of a Dirt Devil will whistle like no tomorrow when you extend the hose to near it's range. Simple as that. No harm, except to your ears, it's just the air in the corrugated hose setting up that whistle. Nothing going on with the motor or anything else, just the air in the hose doing it. It's tough vacuuming the entry steps as that hose extension is right at the whistle sweet (or should I say sour) spot... The only answer is to not vacuum those places requiring extending the hose or wear ear plugs...

[Dick & Pat]

Maybe a crack in the hose that opens enough to let air in when extended?,

or where hose connects into the wall that gives a bit when hose is extended, letting air squeak out?

Dunno....Just guessing

[powerboatr]

I never thought about it, we had a dirt devil in the fiver and often stretched that puppy out, HOWEVER, it wasn't near as suctiony (new word) as this one, they must have made some internal suckasaurus upgrades,
plus i found this afternoon, if the hose is stretched in a long straight line then a sharp curve it starts the shrill. maybe the key is t have a person stand midships and give it a corner bend to slow down or disrupt the air turbulence


i have had the dash apart all morning chasing the microphone feed for the rear camera so i can install a switch to shut it off, until i need to hear the dw telling me where to go

this new learning curve is fun

[The Woodieboys]

Man we hate that whistle! Definately related to the hose and bending it stops the whistle. Only way to stop it from happening.

[tncruiser]

go to a vac shop they can sell you a muffler for your vac
brianj/tncruiser

[RVDude]

Quote:

Originally Posted by tncruiser go to a vac shop they can sell you a muffler for your vac brianj/tncruiser

I suspect you are talking of a central vac exhaust muffler - this won't help at all in this case as the whistle is generated inside the suction hose due to the corrugations in the hose hitting some resonant frequency when you stretch the hose just right. The exhaust is in the basement and does not contribute to the whistle.

[tomsm]

powerboatr - are you sure there's no volume control on the rear camera monitor? When I accidentally left mine turned up, the roar from the diesel exhaust was quite loud. Can't imagine having to listen to that all day...

[adj]

Pulling the last foot or so forward to the inlet will reduce the howl to an acceptable volume. I have actually considered calling Dirt Devil to see if they had a little longer hose.

[powerboatr]

Quote:

Originally Posted by adj Pulling the last foot or so forward to the inlet will reduce the howl to an acceptable volume. I have actually considered calling Dirt Devil to see if they had a little longer hose.

in our fiver the vac was about dead center in the coach and the hose never got streeeetched.
i think until we find a resolution the front entry steps will get sweeped out vice vacuumed.

[soonerdave]

One other thought, make sure there is a bag in the unit. I didn't check mine, just assumed it would be installed, and had a huge mess to clean up in the bay after I used the vac. I know, never assume anything!

[powerboatr]

Quote:

Originally Posted by soonerdave One other thought, make sure there is a bag in the unit. I didn't check mine, just assumed it would be installed, and had a huge mess to clean up in the bay after I used the vac. I know, never assume anything!

oh yeah we put a bag in it first thing, after i removed all the debris someone had sucked up at the dealer.