Old-powered sub "LOUD" hum (not grouding loop)

[Ketel1]

I see there's another thread going on this same topic but I don't want to hijack it in anyway.

I've been reading around, searching, digging, looking around for the past day trying to figure this problem out. My old Audiosource SW6.5 powered sub is humming.

This problem probably has actually been going on for the past half year or so just never used my sub after it happened cause it just got too annoying... Then again I rarely use my system since i'm on my laptop all the time at school. Only time i turn it on is when I have people over in my dorm for some drinks

Yes it is an old subwoofer, got it as a christmas present back when I was in Jr High which was... oh....8 years ago!

anyways, i'm going to include pics and a video clip here for all of you guys to look/hear. Maybe some of you more experience veterans can help me out here. I am truely stumped on this. I thought it was grounding loop from what I've been reading every where.

I went to every single socket in my house and tried out my sub and it still hums. (yes I'm using the 3 pronged adapter from my sub power adapter to the power outlet. you'll see in the video clip it's the white piece)

ok, so maybe fuse? -shrugs- Gave it a shot, had a spare one lying around. Nope, that's not it.

When it's plugged into my 5.1 Panasonic bookshelf system, it delievers the sound but the hum is still there when there's no audio.

Next thing I thought, hrmm.. Maybe it's the 4700uf35 capacitor that's on the circuit board. Have the same power cap. on my HID kit for my headlights on mycar. But i don't want to go through the trouble of unsoldering that and making a big mess. Just wanted to see what all your inputs are.

Video Clip-PhotoBucket, Click On This Can't hear the hum on laptop or regular 2 computer speakers. It can only be heard through a stereo system preferrably with a subwoofer. Yes, the humming sound is LOUD.

that rattling sound is just the bottom of the circuit board vibrating on the case. Not from the woofer.

 

[TLS Guy]

I see there's another thread going on this same topic but I don't want to hijack it in anyway.

I've been reading around, searching, digging, looking around for the past day trying to figure this problem out. My old Audiosource SW6.5 powered sub is humming.

This problem probably has actually been going on for the past half year or so just never used my sub after it happened cause it just got too annoying... Then again I rarely use my system since i'm on my laptop all the time at school. Only time i turn it on is when I have people over in my dorm for some drinks

Yes it is an old subwoofer, got it as a christmas present back when I was in Jr High which was... oh....8 years ago!

anyways, i'm going to include pics and a video clip here for all of you guys to look/hear. Maybe some of you more experience veterans can help me out here. I am truely stumped on this. I thought it was grounding loop from what I've been reading every where.

I went to every single socket in my house and tried out my sub and it still hums. (yes I'm using the 3 pronged adapter from my sub power adapter to the power outlet. you'll see in the video clip it's the white piece)

ok, so maybe fuse? -shrugs- Gave it a shot, had a spare one lying around. Nope, that's not it.

When it's plugged into my 5.1 Panasonic bookshelf system, it delievers the sound but the hum is still there when there's no audio.

Next thing I thought, hrmm.. Maybe it's the 4700uf35 capacitor that's on the circuit board. Have the same power cap. on my HID kit for my headlights on mycar. But i don't want to go through the trouble of unsoldering that and making a big mess. Just wanted to see what all your inputs are.

Video Clip-PhotoBucket, Click On This Can't hear the hum on laptop or regular 2 computer speakers. It can only be heard through a stereo system preferrably with a subwoofer. Yes, the humming sound is LOUD.

that rattling sound is just the bottom of the circuit board vibrating on the case. Not from the woofer.

The issue you have to address is this. Does the unit hum if it only plugged into the AC, and no other wires or anything connected to it? If the answer is no, then likely you do have a ground loop. If the answer is yes, then there is some type of fault in the power supply, or interruption of an internal ground.

 

[Ketel1]

it does hum both ways, when it's plugged into the system and when it's not plugged in but only getting power

 

[croseiv]

I'll say this-That capacitor in your last photo looks gnarly. Almost like it's burnt?

 

[Ketel1]

yeah it does look pretty nasty. It's just that brown wax stuff you see on the back of that last pic. I was just picking at it on the cap to see if it comes off or not so it looks worse.

 

[TLS Guy]

yeah it does look pretty nasty. It's just that brown wax stuff you see on the back of that last pic. I was just picking at it on the cap to see if it comes off or not so it looks worse.

That stuff was put on to stop it rattling.

If you have a meter check out the continuity of the ground plain, right from the input connector. If the problem is not there, and you don't have scopes etc. you won't fix it unless you are very lucky. It is not worth taking it to an expert to fix. At that point recycle it.

 

[Ketel1]

-sighs- figured