Figure this one out!

[sant6236]

Hey Guys~

I am getting feedback or humming and addiitonal bumps here and there from my subwoofer.

Turn the gain up on the amp and the humming increases.

The bumps will come periodically here and there.

Not sure what is causing it, but its annoying.

Any ideas or possible remedies?

 

[cennijimenez]

Did you run the power and rca's with each other? what king of amp are you running? do you have a good flat surface where there is no paint? i know that if you run your RCA's with your power it can cause interferiances, and the ground is a really big deal you want to grind all of the paint off.

 

[tarheeltp17]

subs generally do not play the frequencies associated with engine noise most commonly caused by running signal and power on the same side. Reason being is that on the amp there should be a LPF or Low Pass Filter setting that allows you to cut off frequencies above a certain point where as a full range speaker you'll select HPF where you can't select to not play frequencies below a certain point.

Anyway, sounds like an amp issue or maybe even a loose RCA. Definitely check your grounding point as well as the connections at the amp. Wiggle the RCAs and see if that causes more of the bumps etc.

 

[viper4evr2001]

i had a similer problem with my sub amp it turned out to be a bad cap inside the amp.

 

[sant6236]

I checked the grounding point and I used a dremel to grind away all of the paint.

So it has a good grounding point and still has this issue.

I may try a different grounding point.

The RCA's are infact run along the same side as the power wire, but has one of you stated this should not interfere.

 

[004Gunner]

Route the power wire away from everything else. It should be completely isolated to avoid interference

 

[leftyguns21]

and get better RCA's. you get what you pay for. thats not something you want to go cheap on, heavily insulated RCA's is the only way to go. in addition to running the wires on different sides of the car.

 

[pcpackrat]

If you are using a line level converter then the speakers are acting like microphones to your subwoofer. You are converting the energy created by speakers to line level and feeding it to the amp along with the signals from the radio.

I figured I would add this as some people use the line level converters with the speakers still connected.

-PCP

 

[borgzman]

HUM?
1. Bad Capacitor in the supply stage - replace capactor or add higher capacitance. 2. Highly sensitive preamp in the Stereo( factory defect) - can be solve by shielding it with tin foil and paper or soldering additional grounding to chassis. or soldering a very small mylar caps from the preamp output and send the hum to ground. 3. Mismatch output impedance from stereo amp and the "external amp" - can be solved by adding a coupling resistor in series with input-output, stereo to amp. 4. Improper grounding - file the stereo chasis and solder a wire to the chasis of the 4runner. 5. The output impedance of the amp is intended for lower impedance subwoofer.

What happens here is the audio is picked up from the tuner or the lens of the CD player it is preamplified by a low power preamp and send it to the car stereo main-amp(usually IC type). From the output of the stereo, we connect it to a more powerful external amp. If the external amp is IC type,..you will have now two IC amplifier in series, one in the stereo itself, and one is external. Both have different characteristics and obviously not designed for each other hence the mismatch and causing the hum.
I would choose a "BOOSTER" transistor or transformer type to boost the sound.

Amp are usually ICs. And why would we double the IC amp when there's a built-in one in the car stereo. We need to boosterized that car stereo amp... It hard to explain..but its just my old skol experience in installing sound system.