# Bizarre problem... speaker cuts out... please help...



## lunchmoney (Dec 27, 2007)

So here's my Mazda 6 2.1 car audio setup:

Stock head unit --> 5-channel Rockford Fosgate Amp --> TM front speakers (passive XO's) and a 12" sub

Yes, the stock head unit has line outs... it used to feed the stock Blows amp. Four of the five channels of the new amp are bridged to power the speakers, the 5th channel powers the sub.

So about a year and a half ago, some strange things started happening: randomly, every now and then, one front speaker or the other (never both!) would cut out... in it's place there would sometimes be a ground loop whine, sometimes not ... it would sometimes happen when I hid a bump, and sometimes fix itself when I hit a bump. Other times it would happen just randomly, even when I just turned the car on. Totally random. 

In addition, sometimes the whole system (all speakers) would do a scary WHUMP and all speakers would cut out... this was back when I had a different amp (Infinity). I figured out that the amp must have been causing this, so I replaced it with the RF amp, and it seems to be fixed. 

But the other problem (either speaker cuts out) still remained.

So I replaced the stock head unit with another stock head unit that I got from a salvage yard. That seemed to fix it... then 2 months later it started happening again... (a transcript of what came out of my mouth at this moment would have me banned from the forum).

I know it's from upstream of the amp, because when one speaker cuts out, I can pull over, swap the RCA's on the amp, and then it's the other speaker that's out... so it's gotta be the head unit.

Here's another weird thing: when one of the speakers is out, if I crank the volume up on the head unit it fixes it.

What would cause this? The obvious answer is that the replacement head unit is displaying the same problems as the old one... but what are the chances? I don't think there's anything inherently wrong with how its all hooked up, because it all worked flawlessly for about 2 years... and the replacement one worked flawlessly for a couple of months.

I think my only course of action would be to get an aftermarket head unit and hope for the best... but I'd really like to understand the problem. It's the random nature of it that's so bizarre. Hard to believe it's just a flaky connection, since either speaker can cut out.

Help?


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## asawendo (Nov 22, 2009)

lunchmoney said:


> So here's my Mazda 6 2.1 car audio setup:
> 
> Stock head unit --> 5-channel Rockford Fosgate Amp --> TM front speakers (passive XO's) and a 12" sub
> 
> ...


Have you replaced your RCA connection just to make sure?!

Because based from what you aforementioned above, it looks like a bad rca 
connection to me. Thx


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## The Baron Groog (Mar 15, 2010)

I'd 2nd that, also may be worth checking the line out joints on the HU circuit board and make sure none are dry-do this 1st with your old stereo if you still have it and just re-solder the board and swap HU back over to test


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## asawendo (Nov 22, 2009)

The Baron Groog said:


> I'd 2nd that, also may be worth checking the line out joints on the HU circuit board and make sure none are dry-do this 1st with your old stereo if you still have it and just re-solder the board and swap HU back over to test


Yep check that too. Also you should check your battery/ground wire for any defect. Thx

Best Regards

Wendo


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## lunchmoney (Dec 27, 2007)

asawendo said:


> Have you replaced your RCA connection just to make sure?!
> 
> Because based from what you aforementioned above, it looks like a bad rca
> connection to me. Thx


I still find it hard to believe it's bad RCA's when randomly _either_ speaker will cut out, and _never_ both. If it were bad RCA's, both lines would have to be bad, and there would be no reason why both wouldn't cut out at the same time. It has happened many dozens of times, what are the odds that both would never cut out at the same time?

The RCA is spliced into the harness wires coming out of the head unit, it does not directly receive RCA jacks.

I will double check the ground connections... but I don't see how a bad ground would cause either (and never both) speaker to cut out. Could a bad ground really cause this?

The whole "either speaker and never both" aspect is what makes this whole thing really mysterious. Makes bad connections/bad RCA's hard to believe.

Thanks for all your help!


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## lunchmoney (Dec 27, 2007)

The Baron Groog said:


> I'd 2nd that, also may be worth checking the line out joints on the HU circuit board and make sure none are dry-do this 1st with your old stereo if you still have it and just re-solder the board and swap HU back over to test


Not to sound like a broken record, but how would this explain how either but never both speakers cut out?

I agree it's probably something to do with the electronics in the HU... but it's got to be something more dastardly than the RCA connection to the board, since either but never both speakers will cut out.

Maybe it's something to do with the L/R balance circuitry?


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## jmil1974 (Dec 24, 2007)

Bad ground could certainly do it. Most common annoyance and it can do some really odd things. 
Double check that RCA splice into the HU. It may also be pulling on the harness coming out of the deck, causing your symptoms. This one makes sense since it could cause both. 
Also consider retracing your speaker wiring. It may have gotten pinched and rubbed a small hole in the wiring. Seems odd, but if you routed them similarly, it could happen to both. It's a pain, but running new speaker wire is a relatively cheap fix and/or way to rule something out.
I've had two window motors die simultaneously so odd things happen. Keep checking basics.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

lunchmoney said:


> Yes, the stock head unit has line outs... it used to feed the stock Blows amp. Four of the five channels of the new amp are bridged to power the speakers, the 5th channel powers the sub.
> 
> 
> Help?





> The RCA is spliced into the harness wires coming out of the head unit, it does not directly receive RCA jacks.


So NO, the HU does NOT have RCA outputs correct and the RCAs are spliced in? 

hard to imagine a problem there... 

I'd look for a bad connection, before I looked for bad solder... 

Pull the HU and wiggle the wires WHILE it's playing... see what happens... I bet you find a bad connection..


I don't want to sound harsh, but am I the only one that actually CONSIDERS troubleshooting in the way troubleshooting should be considered? 

You start with the easiest things first and work your way towards the most difficult... 

If you've hacked into the harness, that IS WHERE you should be looking, ESPECIALLY if that hack is providing you with intermittent signal that "sometimes returns after hitting a bump" 

You've already replaced the HU and miraculously it does the SAME ****ING THING.... 

What does that spell right there... a bad connection... one that is NOT of the HU... 

Check your work...


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## lunchmoney (Dec 27, 2007)

Aaron'z 2.5RS/WRX said:


> So NO, the HU does NOT have RCA outputs correct and the RCAs are spliced in?
> 
> hard to imagine a problem there...
> 
> ...


Did you even read my post?

Bad RCA connections can't explain why only one speaker cuts out at a time, randomly either one, and never both. Why never both?

Your aggression is ridiculous.

Thanks for the reminder of why I never frequent this forum any more.


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## Phreaxer (Oct 8, 2005)

It could be something as simple as a wire being manipulated back and forth in a bad connection as Aaron was trying to explain. The back and forth thing is odd, for sure, but I would agree with Aaron and take it a step further and say tear apart that connection and redo it.


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## The Baron Groog (Mar 15, 2010)

lunchmoney said:


> Not to sound like a broken record, but how would this explain how either but never both speakers cut out?


Horrible little thing called chance.

As said by others all that's been done to fault find is change the stereo, no guarantee it was ever the stereo...

RCA's are the most likely culprit, after that where they join the HU as there will be physical stress at that point and the problem seems motion induced-hence my suggestion of checking the board. Dry joints are a pretty common fault with ciruit boards-lost track of the amount of stereos and amps where that's been the issue.

Also, really dumb question and no insult intended, is the amp secured? Again lost count of customers who've come in bitching about the "POS amp" I sold them when it was floating around in the boot secured only by the wires in it's terminals...Even had a guy come in saying the amp I sold him was "****, it just doesn't work" to go out and find he'd earthed it to MDF!!!


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## lunchmoney (Dec 27, 2007)

The Baron Groog said:


> Horrible little thing called chance.
> 
> As said by others all that's been done to fault find is change the stereo, no guarantee it was ever the stereo...
> 
> ...


I will definitely try a new RCA cable, an easy enough thing to try instead of buying an aftermarket head unit.

But I'll be very surprised if that's the problem... literally hundreds of times one, never both, of the speakers has cut out... if it's bad RCA connections, that just defies probability.

Let's also remember that I can fix it by cranking the head unit up... _every single time_... that doesn't sound like typical behavior for a bad RCA connection.

Remember that the "new" head unit was still a used one... who knows how old and how abused... maybe it's exhibiting the same failure mode as the first old one.

Thanks for the help!


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

lunchmoney said:


> Did you even read my post?
> 
> Bad RCA connections can't explain why only one speaker cuts out at a time, randomly either one, and never both. Why never both?
> 
> ...


Did you read MINE? 

I didn't say bad RCA... I said bad hack into the stock low level outs.... 

If it's "that" close, then possibly turning it up jumps the gap... ever consider it? 

This really isn't even that bizarre of problem... it's a car, things come lose all the time.. The "new" HU doing the same thing as the old HU says to me, again seeings how you somehow missed it, bad connection, possibly in the one part of the car actually CUT into... 

If you can't see this, well, my aggression is possibly warranted..


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## The Baron Groog (Mar 15, 2010)

lunchmoney said:


> Let's also remember that I can fix it by cranking the head unit up... _every single time_... that doesn't sound like typical behavior for a bad RCA connection.


Sounds like the board to me, more current flowing generates enough to temporally bond the dry joint, another bump takes it out agin


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## gnesterenko (Mar 17, 2011)

Gonna resurrect this dead thread, but I am having the exact same issue in my car, completely different hardware. IDA-X100 HU running to a JL HD 600/4 in the trunk. This happens VERY intermettenly, and until today, only happened to the front right speaker. Only for a few seconds, and as the poster above, cranking volume fixes issue. Then today, on the way to work, the front left speaker cut out briefly, just a few sconds with a minor static crackle (not loud, but present), and with a similar static crackle, came back on to full swing.

I thought it may be my solder connections on the speakers (soldered 12 GA wires to the quick disconnect tabs), but now reading this, I'm almost positive its the HU. Its connected via RCAs, but I know for a fact that already one channel on my HU is dead (left rear - my rear channels are running of the right rear signal only via an RCA splitter), so it wouldn't be a stretch that the other channels are starting to go as well.

I did just pick up an Alpine HTX-100 imprint kit, which should take the signal from the HU via the AInet cable. I'm hoping this will allow me to put off buying a new HU as those RCA outs are going to be bypassed once I switch to the (4V!) outs on the 100. Though based on some other suggestions above, I think im going to wiggle the speaker wires a bit while they are on to make sure I didn't fudge one of the solder jobs.

This says nothing for my other huge fudge in my build.... if you have a car where the trunk has a little flap type of panel in one of the sides - make sure you put it in facing the correct way. I put mine in backwards without realizing - so that it let water INTO the trunk but not OUT (designed to let water out of trunk in case of emergency/disaster scenario). Didn't realize this until my subwoofer stopped playing one day and amplifier went into permanent protection mode. Started digging around, and found my sub wiring sitting in a pool of collected water in one of the side pockets in my trunk. Thankfully the subwoofer (12" Shiva X2 - one of the last ones made!!!) is OK, but the amp (JL HD 750/1) is most certainly been short circuited and fried. So there you have it folks. You may run your wiring in the most meticulous fassion, you can check and double check all your connections, but one minor oversight and bam - you are out hundreds of dollars. /sigh.

Posting from work, so need this disclaimer:
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."


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## goodstuff (Jan 9, 2008)

gnesterenko said:


> Gonna resurrect this dead thread, but I am having the exact same issue in my car, completely different hardware. IDA-X100 HU running to a JL HD 600/4 in the trunk. This happens VERY intermettenly, and until today, only happened to the front right speaker. Only for a few seconds, and as the poster above, cranking volume fixes issue. Then today, on the way to work, the front left speaker cut out briefly, just a few sconds with a minor static crackle (not loud, but present), and with a similar static crackle, came back on to full swing.
> 
> I thought it may be my solder connections on the speakers (soldered 12 GA wires to the quick disconnect tabs), but now reading this, I'm almost positive its the HU. Its connected via RCAs, but I know for a fact that already one channel on my HU is dead (left rear - my rear channels are running of the right rear signal only via an RCA splitter), so it wouldn't be a stretch that the other channels are starting to go as well.
> 
> ...


IF you can replicate the problem, and get the speaker to stay off, when it's off try turning the gain knob on the amp that feeds that speaker just a hair and see if the sound comes back on.


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## minbari (Mar 3, 2011)

Aaron'z 2.5RS/WRX said:


> So NO, the HU does NOT have RCA outputs correct and the RCAs are spliced in?
> 
> hard to imagine a problem there...
> 
> ...



I have to agree with this. a methodical troubleshooting practice will help more than the "shotgun method"


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## FartinInTheTub (May 25, 2010)

I've had this issue before... It turned out to be a small abbrasion on one of my speaker wires. That also explains the whining sound when it makes slight contact with a grounded surface. I would check your run on that side and replace if needed. Sometimes the simplest things can cause the most headaches. Good luck.


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## SSSnake (Mar 8, 2007)

OK folks here is my $.02...

I used to have these problems ALL of the time. I was running eight amps (and two of them were four channel). Everytime I turned around I had what sounded like alt whine in the output with accompanying reduceded output levels. In troubleshooting one day I removed the RCA then put it back in the amp and viola no noise. I pulled the RCA cable (no fun BTW) and checked it with a meter while moving it around. Dead solid, no issues whatsoever. So I re-ran it back to the same amp and no issues with that cable for about six months. However, one of the other amps acted up during that time. This time intead of pulling the RCA I just wiggled it. Viola everything was right again. Pulled the wire, checked with a multimeter and found no issues so back in the car it went. So I decided to try wiggling all of them to see if the problem abated for a while. It did. 

I have no proof but what I think what was going on was very slight oxidation between the RCA cables and the amp inputs (cables are gold plated and amp was not). I switched to locking RCA cables (Dayton Audio flavored) which really clamp hard between the outside (ground) of the RCA male connector and the outside (ground) of the female connector. The result, well they made it four years without issues whereas before I was wiglling wires every couple of weeks. IMO these locking RCAs are well worth the price.


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## Bluliner (May 16, 2011)

The speaker crackling, going out, and coming back on tells me that it's the amplifier's protection circuitry doing it's thing. The usual cause for something like that is a speaker with a rubbing VC or a speaker lead coming into contact with chassis ground. 

With a DMM, check the speaker leads ON ALL the channels to see if there's continuity with the chassis and check the leads to see if they all have similar impedance. The only bad thing is that something weird could be going on inside the amp, not usually the case, but it's something I've seen before. 

You also may want to take a look inside the door boots to see if you have a bunch of wires that are cracked & exposing the copper. That'll cause an amp to go into fits and will only rear it's head when the car is moving.


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## gnesterenko (Mar 17, 2011)

Bluliner said:


> The speaker crackling, going out, and coming back on tells me that it's the amplifier's protection circuitry doing it's thing. The usual cause for something like that is a speaker with a rubbing VC or a speaker lead coming into contact with chassis ground.


Hmm, I do have quick disconnect terminals connecting to the speakers inside the doors. They are insulated, but there is a bit of metal showing non-the-less. Maybe they are grounding to the door. Will wrap with electrical tape just in case.



Bluliner said:


> With a DMM, check the speaker leads ON ALL the channels to see if there's continuity with the chassis


Good call, will do.


Posting from work, so need this disclaimer:
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."


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## ATOMICTECH62 (Jan 24, 2009)

I had this same problem happen a few times.When I crank the volume the speaker will start to play.Turns out the braided wire that goes from the terminals on the speaker to the speaker cone were bad and moving them around would cause the sound to cut in and out.


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## ejschultz (Oct 30, 2009)

I'm going to once again resurrect this dead thread. I'm running an 800PRS, TS-C720PRS components, and an Alpine MRV-F345. When the system is cold, my right mid does this. I can turn up the volume, get it to crackle and eventually come on. If I turn it down, it will stop playing. Once the system is "warmed up," it seems to play flawlessly at all volumes. Any suggestions for that? Can a speaker not want to play when it's cold? I've never seen anything like that before.


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## gnesterenko (Mar 17, 2011)

Not sure on the temperature, but I figured out my problem. I had soldered wire leads onto my speaker tabs, and i figured that that was where my issue was. So I had a look and see, and partially right. The solder job was actually fine, but when I was terminating the speaker leads with some quick disconnect tabs, I must have overdone it on the heat on the heat shrink, as there was a rather apparent abrasion on the insulation at the actual quick disconnect termination - a bit of metal exposed. This + any bit of moisture in the door and a quick brush against chassis metal = continuity. Re-heat shrunk the terminals and now also wrap the connection with some electrical tape. So far so good.


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## ejschultz (Oct 30, 2009)

I'm letting everything cool down for a couple hours then I'm headed back to the garage to try again. I'm hoping it was a one time fluke... We'll see. I kinda doubt it. If its messed up, I honestly don't know when I'll be able to do any testing in there.


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## ejschultz (Oct 30, 2009)

Well damn it! It did the same thing after it cooled down. I turned up the volume after a minute of playing to get the mid to start to kick back in. It sounded static-y at first, then it started playing but it was very raspy. After a second or two at literally full tilt (62/62, there's a great thread on here somewhere that shows the 800/880 does not clip at full volume) it finally cleaned up and started playing like the C720PRS mid I used to know. I didn't turn it back down to see if it'd fade into oblivion again, like it did last time. I replicated the issue and that was enough to piss me off for now. Any suggestions on what may be causing this? I have a few ideas, but I'm not sure. I'm thinking that either that channel on my HU is going out, the channel on the amp is effed, my RCAs suck (double twisted/shielded Rockfords, about 5 years old), the speaker is on it's way out, or my speaker wire is pinched somewhere along the line. I'm feeling I can eliminate the speaker wire because nothing else is moving on the car to make/break contact with the wire; it was in the ACC position in my garage. I'm a little afraid to test my RCAs because I'd really hate to blow my pico fuse. Again, any suggestions are greatly appreciated. I'll probably start my own thread on this using this post if I don't get any responses in this old, dead thread. Thanks in advance.


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