Ok guys and girls i did a custom install into a S10 extreme and everything went good. What i did was take the factory head unit out and splice my speaker wires into the factory harness and everything still looks factory. The reason I did this was because the kid wanted to keep the factory head unit. The speaker wires i spliced in were obviously run to the amp for an input signal. I ran the amp at max and everything was good. He has a legacy amp that is 4 channel and rated at a 1000 watts max output. and hes got to 10 inch rockford punches in seperate boxs the boxes are crap and are made out of particle board. Well the problem came up when we decided to bridge the speakers. This is what I did tell me if i did it right. I ran the positive speaker wire from one sub to the positive of the other and the negative from one to the negative from the other and then i put the positive on the amp where it said to if you wanna bridge it and the negative where it says if you wanna bridge it. Now the system pounds like crazy but i'm picking up interference from the alternator. When your switching tracks or mute the volume you;ll get a thump thump thump thats constant till you play music. The reason i know its the alternator is because if you put the amp in hi pass filter you'll here the hmmmmmmm and when you rev the engine it goes faster. Also if you shut the radio off you'lll get that but thats because i ran the remote wire to the fuse box and it gets constant feed with the key on thats because he always has the radio on if ne of you know which wire i could splice into at the back of the head unit to get the remote wire only getting power to the amp when the radio is on i would appreciate that, but my main consern is y i'm picking up the alternator and if i should put a noise surpressor some where.
Thanks so much in advance and sorry for the long post.

 

your power wire is too close to the input signal wires (going from the radio to the amp) my car did that, dont run them by each other and that will go away, good luck, it sounds too me like you did everything else pretty much right

 

Ne one else. The reason this is weird is because it wouldnt pick up the interference before i bridged it but i'm guessin when i bridged it it pulled more amps so thats y i had the interference. ????

 

Well more than likely the noise was there before but it just wasn't as noticeable. When you bridged the amp you amplified the output. Therefore making the signal more noticeable. Make since?
As to where the noise is coming from. It sounds like it maybe coming from two places. First thing is install a Line Level Convertor behind the headunit and run a set of good RCA's to the amp. The noise from CDPlayer(can hear it change tracks and etc.) Is because the speaker wires are amplified due to the built in amp inside the headunit. Then take that amplified signal and send it into the amp and it's boosted again. Now with the gains turned all the way up as you stated has really made the signal even louder. That's what I think is causing the Headunit noise.
As for the Alternator whine. I think that is because of the wires you are using to send the signal from the headunit to the amp isn't shielded. The Signal Wires can also pick up noise through body the body of the vehicle not just Power Cables. So that's possibly where you're getting the Alternator noise from.
But by installing a Line Level Covertor and adjusting the gains on the Convertor and on the amp should reduce if not eliminate the noise coming from the Headunit. And by using the Patch Cables that are sheilded and running them away from Power Cables should take care of the altenator noise.

 

running signal cables next to power cables is probably not the cause of your noise. The entire chassis is a ground, and I'm sure everyone's signal cables are running along the chassis!

Ok, so we have a speaker level signal being fed to the amp. Does the amp have speaker level inputs ?? Or did you splice the wires from the head unit into some RCA's ??

Also, never just crank the gains on an amp. It will clip the signal, and make the amp amplify noises you normally would not hear. To set the gains properly, turn them all the way down, turn the head unit as loud as you can with out distortion, then turn the gains up until you hear the speakers distort a little. With subs, it may be hard to hear, so you want to play something with smooth bass, nothing that is distorted to begin with. Once you hear distortion
, back off a little. Done.

If you still have noise, check your grounding. Make sure it is good and clean.

mike

 

thanks a lot guys you really helped me out. And to answer your question Dj the amp does have provisions to have speaker wire used as an input. The place it has it though says its for hi pass but since there is a switch for hi pass and low pass filter i just put the switch to lpf and that solved that problem. Thanks alot guys.

 

Glad to see that you've got it fixed.