ok this is not in an evo but thats kind of irrelevant. i helped my cousin install an amp and sub into his factory HU (2003 tiburon). ive never done an install with the stock HU so its the first time ive used the RCA adapter thing.splcd it into the rear left speaker and when i was putting the panel back on something sounded funny, kind of echoing. whenever there was a vibration on the body of the car, the sub was picking it up. we closed the hatch and damn near blew the sub....is this just a bad adapter or did i screw something up?

 

anybody???

 

Oh wow, this is cool

What's the difference between a microphone and a speaker? Design wise, basically nothing.

a little mister Wizard here:

They are both transducers. meaning they transfer one form of energy into another. In a microphone, they take motion energy (from the vibrations of a membrane), and through magnets inside, turn it into a small electrical impulse.

This electrical impulse goes to an amplifier, and is magnified, then this intense signal is sent down a wire to another transducer (the speaker), which takes these electrical impulses, and through magnets, turns it into motion energy.

put a multi-meter on the positive and negative terminals of a speaker, then yell at the cone. you will see energy produced.... just like a microphone... you catching on now?

Your Left Rear speaker is acting like a microphone. then because you have the RCA adapter SPLICED into the wire, the small electrical impulse being produced by sound in the car is being transfered down the RCA wire to your Sub Amp, being amplified and then coming out of your sub.

cool huh?

To test this, tap on the left rear speaker cone and listen to that sub pound.

 

ok Einstine that doesnt answer my question at all. Ive never used an RCA adapter and to my knowledge, i connected it correctly. Did i not? or is that a symptom of a faulty adapter?

 

look for a grounding problem usually a thump like that is caused from that

 

Wow.. I can't believe this. I totally tell you what your problem is, and you give me grief!!! You just jumped on my "never help this guy" list.

There is no grounding problem.... you are a moron.

You're not using the RCA adapter correctly. Increase your reading comprehension skills, and you might be able to figure it out. Either that, or turn your gain WAY up on your amplifier, and slam the trunk, doing this will blow out your sub, and the echo will go away.

 

hahahaha...niceeeee

 

I know there is not a grounding problem, and it seems you already had me on your little list because you didnt help me. I already stated i've never used the adapter before and it appears you need to increase your reading comprehension skills because its not my stuff as you keep referring to it as "yours". Im simply relaying information (or lack thereof) to my cousin. He does not have, and probably doesnt have access to a multimeter. Are you suggesting that the leads on the adapter are not matching the pos/neg speaker wires? that seems to me the only way to mess that up.

you came off very sarcastic and you know it. this place is designed to disseminate information and im just trying to figure out a problem. I appreciate the input, but be able to take it if you're gonna dish it out.

 

I didn't dish out anything. I wasn't being sarcastic, I truely found it fascinating the situation that's going on.

RCA adapters are not designed to be spliced in. Voltage flows either way down the wires.

RCA adapters are designed to be dead-headed... meaning that they are the terminus. you spliced it in at a junction. Therefore the RCA adapter is getting voltage from the head unit AND from the speaker which is working as a microphone.

You are basically going to need an amp that has an RCA input and output.

Run RCA adapters from both rear speakers, to the R/L input of the amp. on the output of the amp, run RCA adapters back to speaker level, to the speakers.

You designed your setup incorrectly.

I refer to "you" and "your" as you are the OP. I'm not going to substitute "have your friend" as you are the one who posted the question.

 

TempeRacerGuy totally explained why it was happening and the surface fundamentals behind it. All movements of that speaker caused by vibrations from anything (air, voice, slamming doors, trunks) will transmit to the amp and if the amp is on, will become amplified and re-produced by the sub. The sub then produces energy which the speaker again absorbs and you create a feedback loop. Like holding a microphone to close to amplified speakers. I just said exactly what he said all over again.

To answer your questions though, 1. if that lineout converter you purchased is one of those cheap-azz $20 and under ones, then it doesnt have the propper design features to minimize or block feedback loops. That is probably your problem. 2. Your installation is fine and your ground is OK as mentioned before. Tell your cousin to either buy a better lineout converter or get an aftermarket stereo. He can also splurge on external factory processing units like the JL Audio clean sweep or one of those Rockford Fosgate, MTX, or Clarion doodads but an aftermarket stereo would be cheaper. Good luck.

*** EDIT: Or you can do what he said above. Whoops. Totally forgot about that!****

 

well i understand what was happening. the post made it sound like thats a normal thing for the adapter to cause. i dont think many would sell if they all caused that problem.

and also, he was givin the RCA converter/adapter by someone that had it installed before. i spoke with that person on the phone and they verified that what i did is exactly how they had it set up, and it did not have that affect. and with some searching on here, others have it set up the same way.

another amp is out of the question for him so i guess i'll tell him to get a new RCA converter and try that.

temperacerguy, thanks for the input. some of your first post sounded sarcastic to me and i guess what i was asking wasnt exactly clear. i understand what was happening between the components, i just didnt know why it was happening.

again, thanks for the replies