Strange noises coming from subs (possibly a poltergeist)

[jakemccarthy]

When I first turn on my stereo with no music playing I get a strange crackling/static and sometimes a small burst of bass sound coming from the subwoofers whether its running or not. It never used to do this and I cannot figure it out. I have checked all connections and that hasn't helped. I was thinking it is from some sort of interference, but it never used to do this and nothing has changed recently. Sometimes I can undo one of the amp to subwoofer connections temporarily and it stops it for a while. Its not a blown voice coil because I have checked them with a muti meter. Does anyone have any ideas because Im starting to think that my explorer is haunted?

 

[Jasonaudio317]

does the sound change with engine rpm, or have a rhythem, like a throbbing sound? Could be many things. . . Interferance bleed over from rca to ground, ground loop, poor ground, could have lost a low input into the amp, or could just be a pos amp. Hard to say without any more info about your set up. . . sorry

 

[jakemccarthy]

No change with engine rpm,and it still happens when the engine is off. So its not alternator whine. My set up is a kenwood x995, phoenix gold 15 farad power core, phoenix gold line driver, phoenix gold 300.2 amp bridged to 4 ohms, 2 image dynamics idg 12's. Both bass boost and gain levels are set to a little less than half. I have tried to bypass the line driver and it didn't help. My RCA connections seem fine, at least on the amp side. So I guess I will have to check my RCA's on the head unit side.

 

[jakemccarthy]

I just went out and looked at the connections and they all look good. For whatever reason it didn't make the noise even before I started screwing with things, Im starting to think that it has something to do with heat. The past few days have been in the 80's and before that I have never noticed it. And now that it has cooled off a bit it has stopped. Does this make sense?

 

[Jasonaudio317]

Ive has similar effects one time with a orion 2400d. Is the line driver matched to your amps, voltage etc etc? It is easy to burn up the preamps with over loading it due to the line driver. Does the line driver have sensitivity adjustments? if so, try cutting back the signal on both line driver and gains. The heat shouldnt cause that much of an issue. it can increase your thd %, and make the amp less effecient.

 

[jakemccarthy]

My line driver is set to about 25% gain and its not the cause because I have tried bypassing it and it still made the noises.

 

[Jasonaudio317]

well. . . if its not the line driver, and all amps have good connections, then it seems to point to your head unit.

 

[jakemccarthy]

My head unit is brand new, so I dont think thats it. I have read a little about my amp and it seems that one of the transistors sometimes go and that can cause this noise. The only thing is that it is intermittent, and lately it hasn't been doing it. So for now Ill leave things alone until it starts up again.