engine interference

[chaza]

i have two subs and some 6x9, when i turn on the car i get the engine interference, is there any kind of suppressor that i can connect to stop this. my car is a volve if that makes a difference.
some tell me to bridge the power form one amp to the other and the same with the earth, the earth point is a good one. the amps have lf and hf. so im a bit unclear as to the correct set up for the system too.
the music comes out resonably fine except for the engine noise, and not only that, but when i turn the music sound right down to nil, i hear this pulseing at 1/2 sec speed.

can anyone help


thank you

 

[audioman00]

sounds to me like you blew your rca ground. you need to ground the outer shield of the rca connector to the chassis ground. That should eliminate the pulsing sound you are having. you can check with an ohm-meter and see by checking continuity between the chassis of the head unit vs. the ground shield of the rca connector, you should see NO continuity if this is your problem. let me know what you find out. i will try to determine if you have a bad rca ground or just need a noise supressor. Sounds like both to me.

 

[chaza]

thanks for that ill do the resistance test this weekend, about the noise supressor, where can i buy them and where do they fit too.


thanks

 

[j_garcia]

You should have the negative ground as short as possible and going to bare metal on the chassis; basically as close to the amp as possible. If you disconnect the RCAs and the problem goes away, it is your ground. If it does go away, it is the RCA cable itself.

Any automotive audio shop should have things to help with alternator whine.

 

[audioman00]

No problem. The resistance test will actually 'test' the system rather than taking it in to a shopto get rap3d on labor fees. You can fix this yourself I'm sure. the rca's never go bad unless they were cheap to begin with. But, the deck itself may have a blown little surface mount fuse inside the unit on the motherboard. It is common only when the + positive 12 volts from the car has touched the rca ground connector, thus this sends 12+ pos right into the rca's on the deck. No more ground, so the inside conductor of the rca cable tries to act as a ground. That causes the hopping and fluttering of the woofers and / or 6x9's.
If you were to again, ground the rca outter shield connector to the chassis. That will eliminate this problem, w/ out actually fixing the deck. The repair cost is about $100 on a bench. At leaste that is what I used to charge...
The little noise suppressor is $29.99 avail. @ Radioshack. You just simply connect the + to the deck inline with this unit. car batt + -----$$$----- + deck
PM me if you have any questions when doing this. thx

 

[chaza]

hi there
let me explain my configeration,
from the head unit i have two rca leads going to two amps.
1 amp is 1000w and the other is 600w.
the two leads that come from the head unit are split, one goes to the 600w amp and is then slpit for two channels.
the other lead is split then slpit again to go into the four channels on the 1000w amp.
does this sound ok to you

 

[audioman00]

Does the deck have a subwoofer pre-out? Your config should work... but, does the deck lack front/rear/sub ouputs? what make,model is the deck?

 

[chaza]

hi there
just be sure we are talking about the same thing, this system is in a car, ther head unit is the radio, im not sure what the amps are, i dont know what sub out are, all i can tell you is each amp as you will know, has connections for the speakers, what are the front rea sub outs, hear in the UK ive not heard of that before. i havent managed to get the resistance reading of yiour last suggestion yet.
but what im confused about is the two rsa's from the back of the radio are left and riight channel, i assume that is for stereo, so why can i split them as i have with my config, surely the two channels shoulkd follow each other.
on the 1000w amp there is four channels, 1/2 on the left 3/4 on the right, while it is working as you said, should not the two rca's from the radio go to either 1/2 or 3/4 not 1/4 or 2/3 this splitting seems odd, but as you say it works.
what i fail to undertsnd is if i slpit the two rca leads ont to one amp and one to the other, i end up with right channel to one and left channel to the other, so how can i then split the cable the formm a left and right channel, when all i strted with was a right channel only.

god this is confusing

thanks for your help youve been great.



charlie

 

[audioman00]

I know it's a car audio system, deh! ... ok. The "deck" is the stereo in the dash, the amps are set up for more channels than you have on the deck. You need to first off, disconnect everything. Then go to radioshack or wherever sells audio stuff, obtain 2 qty male to two female splitters. Connect one to the left and one to the right on that back of the deck. Now you have 2 sets of outputs coming from each rca output on the deck, 2 right and 2 left. Now it should be self explained.. If you need more splitters just buy em, and install them, but the point of the matter here is: You need to have a L and R running to each amp. The 1/2 3/4 thing is just channels 1 2 3 and 4 separated by the amps design. As long as you have the appropriate channel from the deck going to the amps, you will have stereo balance. The ground issue should be first on your list though. Get that fixed first. Do the ohms test and get back to me.

 

[chaza]

sorry if i gave a stupid question about it being a car radio, i just wanted to be sure we werev talking about the same thing. what you said makes sense now, i got confused about all these wires being split. thanks for your help and ill try to get back you with my findings.

thanks again

chaza