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smashedz28

Need help troubleshooting

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About a month ago I had a local shop wire my car and install a set of components/head unit in my 2011 Malibu. Basically ran all wires to the back for me to put my amps and sub stage in.

I installed a fosgate power 400.4 for my forgate t2 components using the passive xo. Couple different sub setups but always the same sundown saz1500. Extra kinetik hc2000 in the back.

As of yesterday I'm starting to hear crackling coming from the tweets at about mid volume. Kinda strange because this morning I got in there after sitting all night and I was able to lay into it a little with no problems.. For about 2 minutes then the crackling/fuzz starts coming from the tweets again. Figured I blew my shit..it happens. Especially with all the adjusting I've been doin. Out of anger I kept turning it up and I noticed the sub doesn't get any louder either.

So the components basically start crackling/muffling. More or less stop getting louder and sound like shit. But the sub is ran separate why isn't that functioning properly. Everything is fine and good till about 25 on the volume. Last night I reset all head unit audio settings and went to the amps to make sure settings were good and I'm not seeing anything out of wack. Connections as far as visible ones (all amp and battery connections) are right and secured.

Where do I go from here? If I blew my components then ill deal with it but no way in hell I'm gonna just throw another set in there and ruin those too. I need to find out what's goin on. I am heavy on my volume knob at times, just not sure why the sub is acting up. Thanks and sorry for writing a damn book here lol

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I deal with numbers.. Without them, i can't analyze much...

 

Measure everything as it's happening.

 

Measure AC voltage running to sub and components.

 

Measure ohm load when stereo is off and disconnected from amp of sub and components.

 

Measure voltage drop at amp(s) at full tilt.

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Don't waste your time with all that yet. You say the sub does not increase with volume?

Unplug the RCA at the amp and verify what the voltage is doing. It should stop increasing at the point when the sub volume would stop increasing.

I'm betting either a bad sub amp or bad head unit.

If it was just the highs fking up I'd say the crossovers were more than likely mounted in the doors and got wet.

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This is terrible timing on my part. I've just left on vacation for about 4 days. My apology but please offer up advice. I'm not the best with a DMM but do own one. I know the sub is wired right I checked the ohms when I put it in and saw 1.2 at the sub disconnected. The rest I don't know till Tuesday. It was working nicely till recently, no issues other than trying to get a little more output from my sub. But sounded very clean.

When I heard the sound my first thought was "damn I turned it up too loud and blew my comps" but listening more it wasn't just them it affected everything else. Which then made me think my head unit may have been compromised or what the shop installed for me may have been done sloppy. I'm terrible at removing interior panels which is why I had a shop do that part.

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Just unplug the RCA from the bass amp and see if the crackling in the highs stop

At the amp

Edited by Quentin Jarrell

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I would check to see if you are sharing a ground between the amps and unhook the kinetik in the back and test voltage with/without it hooked up to test if you have voltage coming from the front and test continuity from your ground point to the amp to make sure you aren't getting any extra resistance.

Edited by nadcicle

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Disconnected sub amp rcas and same problem.

While I had it disconnected I tapped the sub cone and the sub started 'whining' high pitched sound. Tapped it a few times more and it stops. Wtf is that about. Car was still on and sub connected just rca's pulled.

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Another thing, as I stated I went on vacation. Vehicle sat in the driveway. I was able to listen to it for a few minutes with no issues. Sub played normal, highs didn't get all scratchy for several minutes. Then it started acting up. The more I mess with it the more I rule out burnt equipment (speakers and amps) and point at the head unit

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Low voltage issues could be possibility for the noise, as you stated that after a few minutes the noise started.  Also one last thing, it could be caused by a short, or thermal issue causing an impedance change.

 

As for the whining issues with the sub-woofer, I can presume electrostatic energy was transferred into the amp when you touched it, and it was nothing more than a resonance.  (you stated that the sub was live).

 

I would try to locate the noise.

 

Start by disconecting the remote wire from the sub-woofer amp ( do not let it touch anything )

 

Next, disconnect the rca's for one channel at a time from the 4 channel amp, and let us know if any pair of rca's causes the crackling to go away.

 

Lastly can you take a picture of the amp as it is wired, of the rca's and the speaker wiring.

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Here in maybe an hour I'm gonna tear it down and put my 2 sa12s back in.

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Disconnected sub amp rcas and same problem.

While I had it disconnected I tapped the sub cone and the sub started 'whining' high pitched sound. Tapped it a few times more and it stops. Wtf is that about. Car was still on and sub connected just rca's pulled.

That is called shitty output filtering. When you tap the cone the coil is generating signal that is traveling back into the amp and is being looped back to the sub.

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Disconnected sub amp rcas and same problem.

While I had it disconnected I tapped the sub cone and the sub started 'whining' high pitched sound. Tapped it a few times more and it stops. Wtf is that about. Car was still on and sub connected just rca's pulled.

That is called shitty output filtering. When you tap the cone the coil is generating signal that is traveling back into the amp and is being looped back to the sub.

So that translates to just a shitty amp or install?

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Translate to shitty or broke amp. Is lean more to it being broke. If it was a design flaw it would be obvious as it would do the same thing when a door or trunk were closed causing the cone to vibrate. (Of course the amp would need to be on in order for it to happen)

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That's a possibility I suppose. I bought this amp used maybe 2 years or more ago. One day it popped the internal fuses, I replaced them and never noticed anything again. I have a brand new crescendo bc2000 here I can swap it with but not until I sort out why my highs are acting up.

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Unhook one RCA at a time. If that doesn't fix it unhook one speaker wire at a time at the amp until it stops. (Unhook then hook back if the noise doesn't stop)

Does it make the noise with the car not running?

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I'm not sure if the noise happens when the cars off. As of right now it's all unhooked and removed from the vehicle (subs and amps) I'm taking this Treo out and putting the 2 sa12s back in. One thing I noticed while unhooking it, I may have had the RCAs mixed up at the 4ch amp. I bought the knu rcas that are twisted together. It's a 4ch pair and it has 4 colors. Red black blue and white. I may of not had those right. I assume red and black are 1 set. But I didn't hook up the deck to see if the shop used them that way. Working on it now ill check back

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null-6.jpg

Figure this could be part of my trouble

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Removed everything and reinstalled different subs. Charged battery after noticing low voltage, just hope the battery isn't on it's way out. Completely disconnected rear rcas and speaker wires. Problem seems to be solved. I ran it hard for about 10 minutes and everything is working as it should. I may of had the rcas mixed up and I know battery voltage was low. I checked all fuses front to back and everything was good. Thanks to everyone who offered advice I truly appreciate it.

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It may seem like it has been fixed, but if the amp is indeed broken and the output filtering is out of wack, it's probably a lose component in the filtering section of the amp. Those brands of amplifiers are not known for bad outputs. Just throwing it out there if it crops up again. Don't be afraid to take the cover off and wiggle around components and look for broken traces, unless it is under warranty haha.

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This issue is back. It's strange. Sub amp and bass amp both are affected. As I was driving home from work (45 mins) I was messing with it. Totally feels like a voltage problem. The weak signal plays at lower volume.. Sounds like ass but as I turn it up it almost turns into a solid hiss sound. Vocals in the music disappear as volume increases.

I know last time around I found the rear battery that both amps run from was down to 10.x volts.. I threw it on the charger for maybe 20 mins and reinstalled different subs and moved all the amps. Lasted till yesterday.. Almost 2 months.

I'm gonna head outside soon and check my battery again. Could that be my problem? I'm really hoping its not the deck. I believe warranty is gone since I held onto the HU for about a year before using it. I want to rule out everything else before the deck.

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I now know for sure what my problem is. Re reading my own thread pointed me in the right direction. Voltage! Rear battery showed 9.80 Vdc. Put the charger on it and tested the radio and the problem was gone. Now I know what low voltage can do.

I tested front battery with car off and saw about 12.6 ish ( just drove for almost an hour). I think the battery is just on its way out. Had it ~4 yrs and never charged it really. Guess a battery is cheaper than a new 80prs lol

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