interference when ign turned on

[taloola]

Can some one give me some advise on how to cure a continual hum when the ignition switch is turned to the position just before engine start, I assume the interference is coming from the coil. I have a kenwood 4080r with a pyramid pb442 amp and a longmill bass tube.

I have bought some triple insulated wires thinking this might be the problem, but this has not made much difference. Hope someone can help me

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[mgaidica 10+ year member]

i beleive this could have to do with your ground.. maybe try relocating that..

 

[MikeofTulsa Moderator]

its one of 3 things imo....

1) the amp (poor build quality)

2) possibly the bass tube (never heard of it)

3) bad ground

 

[taloola]

Thank you both for your reply, I tried making a new earth connection directly to the bodywork near to the amp, but it made no difference at all.

The system sounds great when i have the key turned to position 1 only. I have been told the base tube is a good make, although the manufactures may now have gone out of business. The amp is a 4 channel amp 4x75w variable gain s/n ratio more than 85db frequency 15-30khz suitable for 4 ohm speakers,

I have 4 speakers the two at the back are JBLGTO522 4 ohm amp range 5-150 w per channnel, F.R. 55hz-22khz sensitivity 90 DB. The two speakers i dont know much about but i think they are about 80-90watts.

The only thing i can think now is either the system is incompatible? could i have got one of the connections to the speaker wrong. Or is the built in suppressor to the coil faulty (volvo 440 1992) or is the engine earth bad, or panels badly earthed? Im not sure what to try next, hope you can help

 

[xjmadness 10+ year member]

i wouldn't doubt that the amp could be the problem.

I suggest you take a look at these two items at crutchfield. I crossed upon them a few days but have NO IDEA if they would actually work or not.

http://www.crutchfield.com/cgi-bin/S-aMDsgbl7zOc/ProdView.asp?s=0&c=11&g=780&I=127ANS80&o=m&a=0&cc=01&avf=N

http://www.crutchfield.com/cgi-bin/S-aMDsgbl7zOc/ProdView.asp?s=0&c=11&g=780&I=127SNI1&o=m&a=0&cc=01&avf=N

Maybe some1 who has tried these could put some input.