jackal24

Ok heres the deal a couple of weeks ago my cousin installed a custom audio system and all. Theres is one problem that i have noticed and it is the static that it creats if you have the volume at high levels it is not really noticable but at low volumes you can hear a constant running hiss....it also does this when the stereo is completely off which really puzzles me.....If someone could please tell me how to fix this it would be greatly appreciated.

Also i have been having a problem with my amp....It is the new infinity 6 channel...at first it was going off every minute so we decided we had a bad amp and put in a new one of the same type....Then when we did this it works ok but when leaving on for a relativly short amount of time maybe a half hour or so the amp gets extremely hot....Is there a wiring way to fix this or should i just buy a couple of fans and stick them in the trunk.

Any help with these 2 problems would be greatly appreciated. Thank you all very much.

jackal24

How can none of you know this....i mean i dont know it because i am not an audio pro...but come on you guys all do this stuff you can at least help me with something.

eightboy

You need to give details first....

Static noise can be affect by many things:
Unshielded wiring, or bad wiring, of line level audio signals;
Ground loops;
Poor supply wiring;
Signal is taken from speaker level (which are very noisy once amplified).

If your amp is going off then it must be that you wired everything up wrong. Where did you get the supply from? Where did you get the audio signal from? Dont expect people to read your mind and say, "oh yea, its that green; you are not suppose to tie your dog to it...the hissing is from your dog"

Since your cousin installed it, then I might guess you have no idea what wire is what and its pointless for you to ask for help. Look for your cousin for questions.

jackal24

My cousin used all grade A moster cable wires...there in perfect condition...not used....it is a brand new infinity amp....i personally think the ground wiring might be messed up.....but is it possible that the negative and postive connections might cause this.....By the way i am sorry for giving such an attitude problem but i really need a solution for this fast......Thanks for all the help guys and i look forward to more feed back on this problem.

Thanks

eightboy

Perfect condition grade A cables are useless unless used properly. There are two main connections into the amp: power and audio signal.

First of all, where did you get the power (12V supply) from? Is it directly connected to the car battery? Or was is just connected to any random 12V you see?

jackal24

It is hooked up through the car battery along with a power cap

eightboy

Assuming the power is connected correctly...since it turns on.

Now how is the audio input connected? It is important that the positive side connects to the positive input and negative to negative input.

jackal24

See this is what i am not sure about........is there any way i can find a guide on how to take out the radio online.....see i have no clue about the wiring or anything because my cousin did it all.....i wasnt even there when it was being done.

PaddyMurphy

Does the hissing get higher pitched when you rev the engine higher? I had a problem with power cables being too close to audio at one point in my last car. With the amp, too, some need to be mounted either vertically or horizontally for the best cooling, but with what you're describing there must be another issue at work. I don't claim to be an expert, but just want to throw out some ideas.

B-Nez

Also, a general rule of thumb is to not allow power cables to run parallel alongside audio cables. Keep them separate. If they must cross paths at some point, make them cross perpendicularly.

The service manual warns against installing high-powered radio. They're probably mostly referring to a high-powered head unit in the dash creating EMI with the nearby systems. A low-powered head unit with a correctly located and installed amp should be fine. Here is the exact text from the manual:
* If a radio system is installed improperly or of a high-powered type is used, the CIS and other systems may be affected. When the vehicle is to be equipped with a radio, observe the following precautions:
--* Install the antenna at the farthest point from control modules.
--* Install the antenna feeder as far as possible from the control module harnesses.
--* Ensure that the antenna and feeder are properly adjusted.
--* Do not install a high-powered radio system.

That is from the last page of the General Information chapter. The first 3 sub-points I think are the main ones of concern for you.

eightboy

I think 'high-powered radio' is radio transmitters and not audio amplifiers. The two-way radios (walkie-talkie type) that you use to communicate with other people, like used in taxis, emergency vehicles, etc...

An amplifier is not the same as a radio. Many people get confused between the two mainly because almost all head units contains both a radio receiver (not transmitter) and an amplifier. Many amplifiers are properly shielded to prevent EMI, otherwise it would not be sold in America without FCC approval. And the output from the amplifiers are so low voltage, and usually paired with a returning signal, that it hardly emits EMI (unless parallelly put really close). Radio transmitters on the other hand are intended to emit radio signals on the antenna (lots of EMI if its high-powered) and requires linceses from FCC. That is why the service manual tells you to put the antenna far away from electronics.


Anyhow, about the hissing noise:
Two possibilities where you get the audio signal: connected to line level or connected to speaker level. If it is connected to line level, either directly from the head unit or from the bose rear speaker amplifier, this wire needs to be shielded. Those wires with the red and white RCA connectors are sheilded. Line level signals are low voltage; that means the noise is as loud as the audio signal itself. With two wires, there are two seperate ground paths and these can create ground loops: meaning these two ground paths now behaves like a big loop antenna. If the wire reaches from the front to the trunk, this loop is big enough to pick up any noise coming from the engine. So even though the wires are shielded, nothing is shielding the two ground shield itself (yes confusing). Not sure, but I think that is what ground isolators are used for (somewhat filters the noise from ground).

The other possibility is that it is connected to speaker level. Then there should be less noise. At speaker level, the audio signal is much much louder than the noise, so the noise should be not noticable. Taking speaker level signals will add more distortion (minor sound distortion, not noise) to the original signal, but this dont matter since nowadays people dont care about the accuracy of audio (MP3 distorts audio even more). Most people are mainly concern with the 'boom' instead of tune. This is the easy solution where you can simply tap into the rear speaker wires. Speaker level, shorter wires, easy hookup, no need to take out head unit...this is the solution if you just want boom.

B-Nez

Hahaha! I'm such a knuckle-head. Transcievers is what I do for a living, and it didn't even occur to me they might have been referring to that. :o I guess I won't be turning my 8 into a bambulance...:D

jackal24

The thing is when the audio is pretty high the static basically goes away and then at the low volumes it is very noticable... It even statics even when the radio is COMPLETELY OFF...i think it is probably one of the weirdest things ever...i know alot about home audio not so much about car audio...and this static noise is all new to me so dont get impatient on my abbilities i am very new at this stuff.....and thanks for all your help so far...another thing is when i drive to this one certain spot the amp always goes off at this one location...i think this is extremely weird also but i dont expect you all to have answers to that so dont really worry about it. Thanks for all the help so far....and more would be even better. Thanks.