Common cause for subwoofer buzzing - repair guide

Apart from bad contacts in power switches, potentiometers or loose ground connections a common cause for a subwoofer that makes buzzing noise even when disconnected from an audio source is failing main filter capacitors.

They smooth out the AC component on the DC coming from the main rectifier and they have to sustain quite some ripple current over the years and that's whats weakening them.

They may not necessarily be bulging when defective, to be sure use a multimeter to measure the AC voltage across their terminals without load (no music playing), it should be next to zero.

[jimwatson]

Great video, thanks for sharing. Your plain speaking diagnosis helped me solve the problem with my Eltax speaker that had a subwoofer that was buzzing very loudly. I just swapped the blown capacitor for a new one at $1.50 and everything is back to normal. Much better than having to buy a new set of speakers! Cheers.

[randomschittz]

I've just started getting in to electronics and I'm starting to realize that it's most always the capacitors fault.

[szpeedy]

Just took out my vintage stereo system from the basement. Everything was working fine for a day.
All of a sudden, my subwoofer was making the same loud hum when I turned on the power, even without input source.
I was searching around and about to give up until I saw your video. I will take out the crossover and try to replace the capacitors. Now, I have to find my soldering iron! Thanks for the very informative video.

[aladinandyasmin]

thanks for the video. even the description is very helpful.

[clemmtec]

Thank you, You saved me from throwing mine away.

[dragan]

Awesome tutorial 👌 👍. Thanks heaps and cheers from Australia 🙂 👍👍👍

[jlkeegan]

Thank you! This is exactly what I was looking for.

[frank]

I have a set of altec lansing 220 amplified speakers and on the right speaker the input wire connector is missing.What kind of connector do I use or what type is supposed to go there?

[ERRORFACE]

Thanx for your vid m8.
I have a mj acoustic 100 mk2 and because i literary aloud to own my livingroom from 8pm till i die off i listen my stuff on low level and since i got a good deal on this sub and its truly quick and deep i love it. But i was always annoyed by that nois what i heard in the midnight silence . It wasn't loud because daytime u cant pick it up.
But if once u get it it the buzz was just there. So little research and all upon your vid i decided to replace all the capacitors. I got the same brand just in better quality- i guess- tho what i found on the web they are not the best but not crap eather i mean the original and also i dont want to change the sound mutch . On the old caps labelled as tested 13.01.2003 .
And the noise gone i cant hear it .
Awesome .
Thankx again .
O btw the buzz was exactly the sound of the torroid noise if u listen it closely just amplified version trough the speaker.

[chrisconstantinou]

Great video and very well and thoroughly explained.

QUESTION.
Would this solve a constant buzzing sound from the amplifier when it's switched on? In standby there is a hum which is acceptable but when it's powered on there is quite a loud constant buzz/hum. I don't think its a ground loop issue as the sound is there regardless if there is an input source or not.

[VioletDragonsProjects]

majority of the time its the filter cap! but recommend replacing all those caps just to extend its life.

[huaizhongli]

Great video and very helpful. My subwoofer (wharfedale PC10A) sometimes gives out loud bursting noise, all in a sudden, sometimes just works well. I disconnected the input audio cable, and turn the volume control to the lowest level, and found once you switch the sub on, sometimes the loud noise can still come out. I have to turn the power off then. Would you think this is also the cap problem? Thanks.

[AadilMehmood]

I have my paradigm pdr 12v3 making constant humming noise, no other sound is being played by the woofer, even after disconnecting from the source the hum remains constantly there. Are the main filter capacitors the culprit?

[knpg]

Hey i have the infinity tss sub 750 it turn on but because i can see the litler green bulb on but not sound even if i plug sound what u think i could pay attention thanks

[tamilinecreation]

Buddy.. how to repair sounds in SONICGEAR MORRO2 BOX??? Because it's playing in mute., No volumes

[macktheknife]

Hi, great video, I have a heartbeat sound coming from my subwoofer without any input signal. It usually happens after a couple hours of use. I’ve heard it might be the smoothing caps, would those be the same as the main filter caps?

[ronnybarela]

I really need to know the size of the capacitors in parallel with the speaker out pins. Just in front of the two big ones he changed.

[Iron-Soul]

Yup… I disassembled my subwoofer amp, and found 9 bulging capacitors. My amp was from 2014, and two years out of warranty.

[hunterfirestone]

I just got a surround sound system and it works great but when I plug any of the speakers into SL I get a small hum it's really annoying. What could be causing this?

[senhalp]

Is it possible that sometimes it just gets to much voltage line it’s build for 240v and the external power cable gives 250v