low humming???

[tecmo04]

so i just bought 2 MM2124s and when i turn my car on there is a low but noticable hum. Now playing my music loud enough (not a big problem for me) it is imposible to hear. But when im driving home after a long day of work and am not in the mood to become deff then i hear this humming. THe hum also seems to get louder when my car hits bumps, it almost amplifys the bumps. kinda weird i know but any help would be greatly appreciated...

thanks all

[thehaens@cox.net]

Does it get noticebly louder when you accelerate? If so I would suspect it is your electical system. Bad Ground perhaps? Well either way, it is something electrical....but you could put an isolator on it. There are many available. Even at your local radio shack....

Not sure about amplifying bumps symptom....

[neomagus00]

our standard response for this kind of thing is to tell you to check your amplifier's power connections, specifically ground, as mentioned. ensure that it's bolted tightly to bare metal, and that it's clamped into the amp properly. then follow the length of the power and ground cables and make sure they're not being pinched anywhere, and that there's no cuts in the shielding.

just for reference, can you describe your system in more detail? i.e. do you have an aftermarket headunit or stock, etc. i'm inclined to believe that the problem is NOT in the signal path, because it doesn't get louder with the volume control. finally, as mentioned, does it change pitch with acceleration?

[Jstas]

Where is the ground point? Might be noise from an electric fuel pump.

[MacLeod]

I agree with the others. The problem is likely in the wiring and most likely a problem with the ground.

A really simple way to tell is to change the ground to a better, maybe more isolated spot and see if that helps.

[tecmo04]

honestly im not sure where the ground is located. when i bought my system i had the place i bought it at install it. i have a stock head unit concidering i have a 99 sable and am not able to replace it. my amp is the red sony p5 (not sure about the model number) that says it puts out 800 watts. i have a feeling that the power cord is being pinched as it runs along the back seats along the spot where they can be pulled down, which i do sometimes. it doesnt chage pitches. ill have to take a look at it at lunch or after work.

any other sugestions or advice would be graetly appreciated!

thanks for all the help

[neomagus00]

just so you know - and let me be clear that i'm not bashing you for this, this is so you don't embarrass yourself somewhere in front of a hot chick :) - but the p5 makes around 200 watts continuous, that 800 is peak (aka never happens). peak values don't matter a bit.

the power cable being pinched in and of itself wouldn't do anything, but checking to make sure the insulation isn't being pierced is a good thing to do. ditto for ground. to find these, simply follow them backwards from the amp (you may end up pulling carpet and panels to see where they go, it's easy, just go slow and you won't hurt anything). the ground should be anchored to the car under a big bolt, on top of bare metal; mine's under a rear seatbelt bolt. while you're at it, may as well check all the wires - ya never know; i had a noise issue a while ago, and i got so pissed at it that i just rewired the whole freaking car - don't do that :).

quick story - driving to work today, i hear a hissing coming from my right mid; i'm scared for the little thing, so i pull over, spend about 10 minutes trying to find the source of the noise (it's very intermittent), and eventually discover that the cap of my soda/pop isn't cranked down, and it's hissing as i move it around trying to find the noise... frickin pop...

[tecmo04]

thanks for the advise. i know the amp does put out 800 watts. im not a pro but far from a rookie. i was just describing it since i dont have the seriel numbers infront of me. i know sony makes crap but i got a deal i couldnt pass up.

could the problem be from turning the amp up to loud? to my recolection this problem started after i turned it up becuase i wanted it louder??

btw, does anyone know how to take the rear seats out of a 99sable? ive been meaning to do this for quite some time now.

[ilikesound]

i am having the same problem if anyone could HELP me it would be ****IN' RAD. narcotimous@hotmail.com if you figure it out god please tell me someone knows what's going on...

[dmk_187]

first of all was guage is your ground? some people run fat power wire, and scimp alittle on the ground. also, cone noise can be caused by a bad alternator, or the isolator for your alternator is going out. you can also have noise in your speakers if you ran the speaker wire too close to a power wire. same things goes for rca cables to the amp being too close to the power wire. check and make sure your remote wire is not pinched. i had the damndest time figuring out the remote wire will cause noise if the insulation is rubbed thin in a spot.

[ColeM]

I didn't read any of the other posts but is it grounded right? ground it where the tail lights are thats a great spot.

[jdr55]

check ur rca cables they pick up alot of distortion when they are about to go to ****