I cant figure it out, need your guys help.

I have a RF T600-2 amp and two RF P3 shallows wired up at 4ohm each. Avic Z2 HU. Running 4awg to the amp, 60A barrel fuse.

Now for some reason, at random times my subs will start knocking, it usually starts when i have the volume turned down to 0 on the Z2. Also I checked the amp and the stupid amps protection safety mode light flickers on and off each time the sub knocks. It gets louder and louder, knocking at a same constant beat. Even turning the subwoofers off through the Z2 doesnt help. To make it stop I have to turn then vehicle off and open my doors to completely shut everything off, and even sometimes turning the truck back on the subs will still be knocking, then i will disconnect it at the fuse and just leave it for a couple days.

I've checked all my wiring numerous amounts of times, I've changed my ground location three different times. Every time I think that its finally fixed it will start up again out of no where and its starting to drive me crazy. I'm just completely stumped, cant figure out what the hell is wrong. I know its not an over heating problem thats for sure.

Is it possible that I have bad wire or something? thats the only thing I can think of besides that I bought a toast amp/subs. Can anyone shed some light on this please? thanks

 

Take your ohm meter and make sure your subs are at the correct impedence. Just turn it to ohms and connect it to the speaker posts and see what the resistance is.

Also, make sure you've got them wired up correctly at 4 ohms or if they're wired to 2 ohms, make sure the manufacturer states that the amp is 2 ohm stable. There's a lot of good reading on www.crutchfield.com about how to wire subs for different impedences.

If that doesn't work I'd suspect your amp is fried.

 

Re-Check your ground and try unplugging your rca's. If it goes away then it is in front of the amp, if you know what I mean. If there was something wrong with the amp or subs it would still make the noise without any preamps plugged in. Start from there and reply back, I will try and help some more. Most likely bad RCA's.

Devildog101

 

Ok, so I checked the ohms - their good

Ground is good

Unplugged the RCA's, turned the truck on and right away it started knocking, so its definately not the RCA's.

What do you guys figure??

 

Sounds like it may be the RCA ground circuit in your deck . Run a piece of wire to a known ground (can be the same ground location your using for your deck). Then the other end , wrap around the barrels of your decks RCA"S , while they are still plugged in to your amp . Turn on the the deck . If the noise goes away , turn radio off , undo the wire from the rca's , and simply run it to the decks chassis (Preferably the back of deck)using a ring terminal and a small short metric screw that might of came with the deck . ,put radio back in .Enjoy

 

If his RCA cables are disconnected from the amp/HU, then doesnt that mean the HU is not sending a signal to the amp.....
amp could be fried

 

Oh , I didn't see where he said he unplugged the Rca's and the amp still made the noise . If the amp makes this noise while not plugged into the deck , then yes I would agree that there is a problem with either the amp or the speaker wires running from the amp to the subs .

 

I know for the speaker wire I used from amp to sub box and to wire the subs inside the box was a home audio 16 awg wire I had plenty of kicking around. I wouldn't think this would pose a problem though?

I built a stereo in my garage using old factory door speakers, old sub, old deck and amp using the same speaker wire and sadly the stereo performs better then my truck set up - haha.(can post pics of you guys want, its actually pretty sweet).

Also, I've figured out that the knocking only comes out of the right side sub and not both. I rewired the subs to check and see if it was a toast sub but the knocking still comes from the AMP RIGHT SIDE. So what the hell, I'm guessing my amp is half fried. Hopefully this shiat is still on warranty.

 

I would use nothing smaller than 12awg wire for subwoofers. (unless they are really low powered ones).

 

yea, if your RCA's are unplugged and its only coming from the one side, then yea, i would guess the amp is screwed....doesnt really make sense

 

1 last thing you could check.. disconnect the speaker wires to see if the amp flickers on/off of protect, just to be sure your amp is toastified. also touch the speaker wires together w/o RCA's plugged in to see if you could recreate the problem with the flickering, maybe when the subs aren't moving the +&- sides of the voice coils touch. the subs could be going out and causing the amp to go into protect.