amp probs

[BimmerBoi]

i fitted a amp to run the rear speakers

all works ok but when i have a cd on and the volume is set very low so that the cd isnt heard i can hear the radio though the amp'd speakers even though the head units set to cd, any ideas??

[mrLEE30]

this can only be a fault in the head unit, i assume the channel you can hear is the one the head unit was last tuned into? there is no possibilty for noise to be picked up from the amp tuned to such a high frequency as FM radio broadcasts at.

either take the HU back and ask for replacement, or have a channel stored with no signal (i.e. a silent frequency such as 88.1) and always select this channel before you put the CD on.

mrlee

[BimmerBoi]

i had a play around with it earlier, the rear output is right next to the aerial output, if i switch the rca leads the the front output which is located further away from the aerial i didnt get the interferance.

yes mr lee is picks up the last station i was listerning to, like your idea about tuning to a silent frequency

[secondtimelucky]

Also caused by a bad earth in the RCAs, Try bridging a piece of wire from the outer connection on the affected RCA plug(s) to the earth on the amp/battery and see if this helps. Or try higher quality RCA' s which are fully shielded, HTH

[mrLEE30]

this cannot be the RCa picking up interfearance as the RCA lead could act as an arial but it would pick up a huge range of frequencies, where as in his case it picks up one particular frequency which happens to be the one the stereo is tuned into - so the noise can only come from within the stereo head unit, better quality shielding will not stop this. he must replace/repair the head unit or detune to a silent frequency.

[secondtimelucky]

in his case it picks up one particular frequency which happens to be the one the stereo is tuned into -

I forgot that bit thought it was a random station that was picked up

[BimmerBoi]

fitted another head unit, sorted