"AestheticsInMotion" (aestheticsinmotion)
10/14/2018 at 14:38 • Filed to: None
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"AestheticsInMotion" (aestheticsinmotion)
10/14/2018 at 14:38 • Filed to: None | 0
| 12 |
I’m frustrated. I’ve spent 10+ hours over this weekend trying to fix something—and I managed to get it working—only for it to crap out again.
My subwoofer just doesn’t want to work with me. It stopped working about a week ago, intermittently. I assumed there was a bad connection because this was my first wiring job, and my car is... Vibration-prone. Opened up the dash, looked things over, re-did a connection, jiggle some wires... And the sub started working. After an hour of driving, it cut out again and I haven’t been able to fix it.
I’ve got a 4-channel amp. The rear two channels are powering the left and right door speakers, and the front two channels are bridged to power the sub. I tried swapping the door speakers to the front two channels, and they worked just fine. The sub didn’t work hooked up to the front or rear channels. So the amp is probably not the culprit? Swapped the RCA line in’s that go from the head unit to the amp, still got no change. So the RCA cables are fine. The headunit itself seems to work. I can fade from Front to Rear, which makes it pretty easy to tell if the subs working seeing as my front channels are 100% subwoofer.
I’m getting zero volts on the multimeter when testing for power to the sub, but... I’m also getting zero volts from the speakers that are working just fine so... User error? 12.6 volts on the battery, not sure why I can’t seem to get a reading on anything else.
It has to be a power issue though, right? If everything else is working?
You know what sounds nice right now? A brand new car, that just works.
(update) I removed the sub from the enclosure and... It started to work. I think I can assume that this means any bad connection is somewhere from the sub enclosure to inside the sub. Annoying, but probably the best outcome. At least I won’t have to dig around in the dash anymore.
Future Heap Owner
> AestheticsInMotion
10/14/2018 at 15:01 |
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When you say “testing for power”, what exactly are you doing? Are you trying to test literally for power, i.e. wattage? I think that’s non-trivial with the AC current, and would require wiring the voltmeter in series (which scares me because audio systems push real power). I’ve never heard of speaker cables that couldn’t transmit the load properly as long as they weren’t broken, so I think testing for low resistance to make sure the connections are all good is sufficient.
Do you have access to another receiver (such as one in a home stereo system) where you could hook up the subs?
Highlander-Datsuns are Forever
> AestheticsInMotion
10/14/2018 at 15:27 |
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I got a C in circuits so I am no help at all here. My feeling is it’s in the subwoofer itself or a secondary amp.
CarsofFortLangley - Oppo Forever
> AestheticsInMotion
10/14/2018 at 15:50 |
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Hey, I was... not shopping for Miatas... and found this.
https://vancouver.craigslist.ca/rds/cto/d/parts-car-1990-miata/6714112726.html
Less than $700 USD.
MM54
> AestheticsInMotion
10/14/2018 at 16:01 |
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From your diagnostic (which is pretty well done) it sounds like you’ve determined the issue is in the wiring to the sub or the sub itself, which is good because nobody likes working in the dashboard.
You won’t see any DC voltage on the speakers, they’re AC (and if there was 12VDC the speakers would let the smoke out after a few moments).
If removing the driver from the enclosure made it start working that sounds quite a bit like something has vibrated loose in the wiring there - either where the wires enter the box, where they attach to the frame of the speaker, or (hopefully not) where the braided wires hop over to the cone. I would be most suspicious of the wiring between the clamp terminals on the side of the box and the terminations on the speaker itself.
Hard to say much more without seeing it, but hopefully that gets you in the right direction. Intermittent contacts can be a real pain to troubleshoot, so hopefully you find a smoking gun (or re-seat everything and it’ll work fine for the next year or two).
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AestheticsInMotion
> Future Heap Owner
10/14/2018 at 16:20 |
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Voltage, I think? Multimeter set to DC voltage, and 20 volts (it’s a cheap harbor freight meter).
No other receiver, but I think something might be loose in the sub itself. See the last update.
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AestheticsInMotion
> CarsofFortLangley - Oppo Forever
10/14/2018 at 16:21 |
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You'll join the club someday, and I'll be so happy.
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AestheticsInMotion
> Highlander-Datsuns are Forever
10/14/2018 at 16:21 |
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Yeah, subwoofer. It's working again, but all the wiring I can see going into the sub looks great, so I may have to take the sub apart at some point
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AestheticsInMotion
> MM54
10/14/2018 at 16:25 |
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Ah. That would explain the multimeter not showing what I was expecting. I guess I just thought all things electrical were 12VDC in the automotive world...
Everything looked good between the subwoofer cone and the clamp terminals, but I redid everything n ot soldered just to be sure. It's working now but we'll see
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MM54
> AestheticsInMotion
10/14/2018 at 17:17 |
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If you have an analog (needle-style) voltmeter, you could put it on the terminal and the needle would jump around and bounce more-or-less with the music, but that’s about all you can get on speaker wiring without an oscilloscope.
Redoing the connections may be all it takes, might fix it for good, might buy you a few days, weeks, or years. If it acts up again, I’d consider reflowing any soldered connections (that aren’t part of the speaker assembly from the factory)
as well as cleaning/tightening any clamped ones.
merged-5876237249235911857-hrw8uc
> AestheticsInMotion
10/14/2018 at 23:17 |
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Second MM54s comments. Those speaker wire terminals in the enclosure sides are notorious for crap connections. I used to just run the speaker wire through a drilled hole in the enclosure and apply ample clear sealant at the hole. Works great and allowed me to run larger speaker wire from amp to speaker direct. And I’d also give them a nice twist to try and cancel out any noise in the line as well.
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Future Heap Owner
> AestheticsInMotion
10/14/2018 at 23:30 |
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Audio is always AC to & from the speakers, because of how speakers work: the AC voltage directly encodes the pressure wave of the sound vibrations. The magnet in the speaker translates the AC voltage into sound pressure by moving the speaker diaphragm in and out, which compresses air to restore the original pressure wave (i.e. the recorded sound).
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AestheticsInMotion
> merged-5876237249235911857-hrw8uc
10/15/2018 at 03:22 |
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Hmm. Getting rid of two potential points of failure. If I have any more issues I'll definitely try that