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Discussion Starter #1
I have this weird problem with my Bose stereo system: When music is playing, say, at value 30, front speakers are quiet (at least I think they are). But when I raise the volume, the speakers (one by one) start to sound as if they were stuck in some way.

What's causing this kind of behavior??
 

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^^^

Quite right.

If that fails, it may actually be the voice coils of the loudspeaker units which have become slightly seized owing to corrosion, though. If this is the case you'll likely need new drive units.

Removing the grilles and gently prodding the cones to check for free movement will give you an idea of whether this is the problem.
 

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Resistance due to corrosion will be constant with voltage so it won't cause a surge. Also it's highly unlikely to affect all speakers.

I've never heard of seized speaker coils but you'd expect to clearly hear distortion if the movement of the speaker is being impeded. Again, it's very unlikely to affect all speakers together.

Much more likely that it's an electronic fault in your head unit or the Bose amp in the boot. My guess would be the Bose amp.
 

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Resistance due to corrosion will be constant with voltage so it won't cause a surge. Also it's highly unlikely to affect all speakers.
......
a) according to op, it's only front speakers
b) higher voltage due to turning up the volume will (temporarily) bridge the corrosion layer....

I've had exactly same problem on my car, solved by cleaning the door connectors ...;)
 

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a) according to op, it's only front speakers
b) higher voltage due to turning up the volume will (temporarily) bridge the corrosion layer....

I've had exactly same problem on my car, solved by cleaning the door connectors ...;)
A higher voltage can't "bridge the corrosion layer" (unless it's a very high voltage indeed) because that's not how electricity conducts. I'm glad you found an easy fix for your problem but I don't think it was down to magic electrons. The connections in a car are complicated and not often well designed so I guess it is possible for a dodgy connection to somehow affect the audio system in this fashion. You're right in that cleaning connections is a cheap and simple place to start a diagnosis.
 

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I have the same issue with my Bose at times. Turning up the volume loud does indeed temporary fix it.
 

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In both the 147 and 156 I owned with Bose, the subwoofer didn't activate until I'd adjusted the volume up or down by 2 increments. Is this what you're noticing?
Others noted the same thing and one very determined owner did eventually get it resolved by sending the head unit back to Blaupunkt for a firmware update.
 

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Discussion Starter #10
And to be exact, this is more common for the left speaker. I've shoot some video about the issue, I'll upload it later. :yes:
 

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https://youtu.be/ohttMzCFP6Y

Here you can hear the problem. After a few seconds, you'll hear how the volume suddenly rises. I was raising the volume step by step up to 36...

E: and this is the left speaker.
That's a big change in gain for a bad connection to be responsible. My Bose system would change volume by a similar amount although it used to do it by itself and not depending on the head unit volume control. I changed the Bose amp to fix.

Please do wiggle and clean your door connector before jwq does himself an injury.
 

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Don't have Bose system, but had a similar issue (not the same) with front speakers. On some days they didn't start to work until the volume was higher than 25-27. On other days they were fine.

I did it a non-scientific way - as advised by many Alfa owners I cleaned those round door connectors using Maplin contact cleaner.
Maplin Contact Cleaner 200ml | Maplin

It worked and speakers has been working fine since I did it.
 

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Discussion Starter #16
I'll try that, I think I can avoid all possible harms (probably). But it's gonna be hard to tell if it makes any impact on the issue as the speaker works just fine for a while after it has "cleared its throat"
 

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Discussion Starter #17
Okay, let's see what I have:

Did some testing today and wiggled the connector (without disconnecting it). As I wiggled (and I wiggled it hard:smoker:), the speaker indeed stuttered. Next step was disconnecting the connector and using some contact cleaner. Now touching the connector won't cause any stuttering, so far so good.:biglaugh:

We'll keep eye on the situation:thumbup:
 

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Okay, let's see what I have:

Did some testing today and wiggled the connector (without disconnecting it). As I wiggled (and I wiggled it hard:smoker:), the speaker indeed stuttered. Next step was disconnecting the connector and using some contact cleaner. Now touching the connector won't cause any stuttering, so far so good.:biglaugh:

We'll keep eye on the situation:thumbup:
:thumbup:
 

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How odd, had this exact problem earlier this week - no output from right front speaker until volume level raised a lot, then it burst into life and has been fine at all levels since.
 

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Discussion Starter #20
Years ago we had a Volvo S60, which had exactly the same problem. About once a week you had to raise the volume up and all problems cleared up:yes:

But testing the connector is rather easy: you don't even have to disconnect in (in some cases).
 
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