Annoying humming

[emai1paul]

Hi

for some reason my 6x9 are playing a annoying humming sound (high pitch) wen ever i accelerate, rev.

Please help.

 

[april]

Hehe, I got that too from my fronts I think (?), but its not too bad if you turn it up. Think Rich said it was dodgy RCA leads??

 

[emai1paul]

Argh myns really bad.

LOL

 

[april]

Oh dear! I can only hear mine if I have the volume down too low!! lol

 

[Lagerlout]

Noise suppressor. Available anywhere. A trained monkey could fit one. Search google.

 

[Lunner]

Is it likely to be interference being picked up by the speaker cables, are they cheapo ones?

 

[Lagerlout]

.... check your earth aswell......

Oh and have a look http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/noise.htmlhere.

 

[cnic69]

hummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

[Edited by cnic69 on 06 June 2004 at 7:23pm]

 

[BRUN]

have you got an amp ?

if so, make sure your RCA and speaker cables are on a seperate side of the car to the power cable for the amp

also make sure your earth is VERY good, proper bare metal !

 

[Jim.]

Quote: Originally posted by BRUN on 07 June 2004


have you got an amp ?

if so, make sure your RCA and speaker cables are on a seperate side of the car to the power cable for the amp

yeah.... i have n still have the noise even with them at opp sides of the car.

earth is attached the bolt in the boot that holds that big plastic thingy down

 

[april]

Still got this problem??

Mine has got worse since I had some bodywork done and now it is drving me potty too!!!

Anyone got any other ideas on this??

 

[RB_172]

Being the sad perfectionist I am, Id still like to fix this for your because the job isnt complete without it.

Trouble is, Alex stole ( ;-) ) the RCA leads Id got for you to replace the crappy ones you had.

Im pretty sure hes not using them so Ill get them back off him one day.

 

[april]

It was hardly noticeable to be honest, but since they repaired my car it has got really bad and whistles like mad!! Not sure what they could have done to make it worse though?! :s

The door speaker is still out too, but have checked the door and the amp, so it can only be the HU connections that are at fault?! It comes on everynow and again, so I dont think its the speaker, just a connection somewhere.

You dont have to do that though Rich!! I owe you for an RCA lead still!!

 

[RB_172]

simply swapping over the left / right rca channels for the front speakers at the amp would soon tell you if its a problem with the HU. It would make the other side cut out.

If its still the same speaker, put the RCAs back in the correct positions, then try swapping the wires to the speakers on the amp. If its still the same speaker, its something after the amp - i.e. the lead to crossover -> onwards to speaker. If the speaker changes and the other side cuts out, its the amp itself.

 

[april]

Cheers - will try that Rich!

Any idea why the interference noise would get worse?? The body shop would have had to strip the drivers side of the car out and the whistling appears to be coming from the tweeters.

 

[Glennclio16v]

Also Rich at what point do the speaker cables from the crossovers to the front door speakers join?? Is the connection behind the dash?? :s

 

[RB_172]

erm... no, not really. if you unplug both sets of leads from the amp, youll be able to tell if its picking up the noise after the hu. Does it still get louder as the revs build up?

It could all be related so new rca leads might fix it. (I thought the noise always came from the tweeters anyway?)

Would they have touched the earth in the boot? re-routed the speaker wires or anything? (Maybe twisted them round eachother?)

Theres so many things you need to try in order to diagnose humming noises! I spent ages (and I really do mean ages!) before I found the problem on mine after I last took it out of the boot. It turned out to be a weird connection on the capacitor!

Anyway, if youre up for it, maybe another lunchtime drop off would be in order. A couple of hours should be enough to rip the old rcas out and do some more diagnostic work! Ill understand if youd rather look at it yourself though, in which case, keep updating me on what happens as and when you remove wires! I really would like to get it sorted, its amazing how these little things still annoy me 6 months down the line!

 

[RB_172]

Glenn, yeah the cables for the door speakers join at an ISO extension block behind the radio.

Theyre soldered on - complete with heatshrink. I guess one could have a dry joint.

Tweeters, as you probably know, are on their own new cable with no joins.

 

[april]

Yeah does still get louder when you rev the engine and is considerably louder now and was always coming from the tweeters, but is just much more noticeable.

Checked the earth and it looks fine, tried to check the speaker wires and they seemed okay but its still a possibility - they would have had to pull it all apart to replace the door and rear quarter!!! :s

 

[RB_172]

I expect the tweeters just respond to the interference better than the other speakers, thats why its so noticable from them.

Ahh yes, Id heard something about you having a spot of bother.

Cant have been that long after youd had the wing repaired after that poor girl reversed into it! Did they actually get you a new wheel for that in the end?

Personally, Id start by replacing the RCA lead with one the same as the other one you got, and then go from there. Having now seen Glenns install (in the for sale bit), he must know what hes doing! Get him to strip it all out or just trace every wire and ensure theyre all connected ok. Again, speaking from experience of my own hummmmming, checking connections are tight isnt enough. pull the connections apart (unscrew earths etc) and then reconnect them. The one on my capacitor was rock solid but still caused a sh1t load of noise to be introduced into the system.

Good Luck!