RTH: Possible amp issues/smoke coming from center dash speaker (1 Viewer)

[TXMeatball]

2010 LX. Sitting on the side of the highway right now. Earlier today while driving I heard a thud from what sounded like behind the infotainment and saw "Bluetooth disconnected" along with my sound being killed. Pulled over and can't reconnect, the audio part of the console with the volume/tuning knobs was unresponsive. Couldn't reconnect with Bluetooth or get fm/am to play. Could turn it on/off with the steering wheel controls but that didn't do anything. Turning off and on fixed that.
Just now while driving again I start hearing a high pitched electronic squeal playing on top of what I had coming from the speakers and see smoke/electronic burning smell coming from the center vent/where the light sensor is. Pulled over immediately and shut it off.
What's under this center vent? I'm not sure if my amp is dying or what, my infotainment was working normally. Not sure if I should leg it back or go with a tow.

 

[Sandroad]

I’d tow It. The earlier thud must have been something heavy coming loose. Burning smell and smoke are the flags for a tow. Wiring should be protected by fuses, but smoke is not good. Are you in situation where a tow is a option?

 

[bloc]

I’d start finding any fuses associated with sound/nav and pull them, and get home. Which might kill your AC..

 

[TXMeatball]

Legged it home, kept the radio/ac off though. Everything's acting normal as it should which is weird. Forgot to mention- both these things happened after driving 2+ hours. Maybe something's getting hot over time? Gonna pull the infotainment apart and see what's going on back there.

 

[TXMeatball]

Infotainment pulled apart. No obvious burned wires or anything. Pulled center speaker(tweeter?) And smelled the soldering. Not an electronics expert, but it smells smokey. Sure enough, the cone looks a little burned/deformed where the wires connect to it. Pretty sure this is the culprit of the smoke/smell. I'm thinking it's being overdriven by the amp if it got this hot?
I have one of the few non-ML LXs so there isn't a lot of info on the system out here.
I was listening to music a bit louder than I usually do (35 vs 26 level). That combined with the long distance driving (2 hrs+) seems to be overdriving the speakers? Gonna pull the amp and check that next- I don't think it should be causing speakers to cook like this.
Anyone knowledgeable about audio opinion here would be appreciated.

Edit: forgot to add pics

 

[bloc]

Speaker looks fine to me. Typical soldering..

 

[TXMeatball]

Kinda hard to see because of the mesh. The speaker cone is melted/burned/deformed. Can also see in the 3rd pic I posted earlier. Trying to figure out of it's an amp issue cooking it or just listening to music too loud for too long and overheating it.

 

[bronc076]

Rarely does the source of electricity cook something, meaning a shorted speaker would cook an amp but amp failure frying a speaker is not unheard of but rare. Do you have a multimeter to check the resistance of the speaker? With a 9v battery like a smoke detector takes you can verify cone movement By momentarily touching the battery contacts to the speaker wire connections with the speaker out of circuit. If it ohms out good and the cone moves freely the speaker is probably okay. Is the impedance of the speaker printed on it anywhere? Typically car speakers are 4 ohms.

Have you given everything else back there the sniff test looking for something burnt?

 

[bloc]

Kinda hard to see because of the mesh. The speaker cone is melted/burned/deformed. Can also see in the 3rd pic I posted earlier. Trying to figure out of it's an amp issue cooking it or just listening to music too loud for too long and overheating it.
View attachment 2753278

Ah, got it.

I’d be absolutely shocked if merely listening to music loudly could melt a speaker cone. Toyota just doesn’t let stuff make it to market without testing of that type.

Then again, I don’t have any other explanation.

 

[TXMeatball]

Rarely does the source of electricity cook something, meaning a shorted speaker would cook an amp but amp failure frying a speaker is not unheard of but rare. Do you have a multimeter to check the resistance of the speaker? With a 9v battery like a smoke detector takes you can verify cone movement By momentarily touching the battery contacts to the speaker wire connections with the speaker out of circuit. If it ohms out good and the cone moves freely the speaker is probably okay. Is the impedance of the speaker printed on it anywhere? Typically car speakers are 4 ohms.

Have you given everything else back there the sniff test looking for something burnt?

Speaker is dead, no movement from a 9v battery. Also the melted cone is definitely what started smoking, still has that electronic burning smell. I'm thinking of chalking this up to a weird set of circumstances that contributed to its death (assuming the amp is fine, which I'll just monitor).
On another note: the OEM part is $140 LOL. I've had luck with Dayton Audio in the past, gonna replace it with one of their same size and 8 ohm ones. OEM is a 6 ohm.

 

[Sandroad]

Speaker is dead, no movement from a 9v battery. Also the melted cone is definitely what started smoking, still has that electronic burning smell. I'm thinking of chalking this up to a weird set of circumstances that contributed to its death (assuming the amp is fine, which I'll just monitor).
On another note: the OEM part is $140 LOL. I've had luck with Dayton Audio in the past, gonna replace it with one of their same size and 8 ohm ones. OEM is a 6 ohm.

But……you haven’t figured out what the thud was. And, a shorted speaker would not likely have caused all the other issues that happened. IMHO, the blown speaker was a symptom, not a cause (though the burning smell and smoke likely came from that). Before you reassemble, look deeper for what caused the thud.

To your other question, yes it is possible to overheat a voice coil and burn out a speaker, but not by ordinary mortals. Your ears could not take the sound pressure level long enough to do that. I’ve blown the foam surround off of woofers, but the voice coils held up fine.

You’ll be fine with a 8 ohm in there instead of 6 ohm, but first find the cause of the failure.

 

[TXMeatball]

But……you haven’t figured out what the thud was. And, a shorted speaker would not likely have caused all the other issues that happened. IMHO, the blown speaker was a symptom, not a cause (though the burning smell and smoke likely came from that). Before you reassemble, look deeper for what caused the thud.

To your other question, yes it is possible to overheat a voice coil and burn out a speaker, but not by ordinary mortals. Your ears could not take the sound pressure level long enough to do that. I’ve blown the foam surround off of woofers, but the voice coils held up fine.

You’ll be fine with a 8 ohm in there instead of 6 ohm, but first find the cause of the failure.

Amp and wiring there looked normal. Wiring behind infotainment and around surround where smoking came from checked out as well. The smoke definitely came from the dead speaker. I'm still thinking my amp is doing something funny, but have no to way to check that aside from swapping in an entirely different unit. Check the dead speakers connector to see how much power its getting with a multimeter?
I'm also thinking maybe the radio unit. When my sound cut off the first time the physical buttons were completely unresponsive. The steering wheel controls could cycle between BT (which couldn't reconnect) and not BT (couldn't switch to FM/AM/Satellite). Turning off the LX and turning it back on fixed that. Does the amp power the radio unit directly? And then the radio powers the speakers?
Right now it's put back together (sans dead speaker) and functioning normally. Even immediately after both incidents restarting the LX caused things to go back to normal. I think it's weird both of these things happened around the 2 hour mark; first being me coming from San Antonio to Round Rock area and then Holland to just outside Schertz.

 

[Sandroad]

What was the thud behind the infotainment center that killed the audio and BT?

The easiest way to check wiring to the speaker is to hook up a cheap one and try it out.

 

[bloc]

The thud could easily have been the speaker itself.

 

[TXMeatball]

The thud was probably road noise and more of a coincidence. I shook the radio and infotainment getting them out, neither rattled. All plugs were firmly seated too.
Replacing the dead speaker with a Visaton FRS7-8. If that one burns up I'll probably go further into replacing the amp.

 

[Sandroad]

Be interesting to see how this progresses. I hope the new speaker is all that's needed.

 

[BrainDoc]

I had something similar with a trunk fulll of smoke in the past, back when I used to put more into sound systems than the car was worth...
It sounds like you cooked the voice coil of the speaker.
Hopefully a speaker replacement is all you need.

 

[TXMeatball]

Took apart the old speaker to jury rig the harness for the new one- voice coil was baked. Is that something that can happen normally (albeit rare/age related?). Otherwise the install of the new speaker went straightforward. New speaker isn't as dark-sounding as the oems ones, it's nice to get a little treble. Center channel is restored and there's nothing abnormal. Will update if anything else happens or catches fire.

 

[Sandroad]

Thanks for reporting back. Looks good. I’m glad a cooked voice coil was the problem. It’s amazing how many other issues that caused! Yes, rare, but voice coil failures do happen.

 

[BrainDoc]

A fried voice coil can wreak havoc on an amp. Most car audio amps are designed to work between 2-8 ohms. You can sometimes see 1 ohm applications. When the coil burns up it will melt the insulation on the thin copper wire that composes the coil and the wires short out. This changes the impedance and if it is a smarter type of amp, will put the amp into a safe mode or turn it off completely. This is with the hopes of not damaging the amp by pushing against a resistance outside of its normal operating parameters.

Now hopefully it was an isolated defect in the coil itself. What may also have occurred is the amp is malfunctioning and the current output becomes distorted and may lead to transient excess wattage. Basically like driving a speaker with DC current, this would quickly force the cone in one direction and could create that THUD noise you mentioned. After a short period of being in the ON/OVERDRIVEN position that speaker coil heats up melting that insulation we mentioned earlier, effectively shorting out that coil.