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Electronics => Beginners => Topic started by: Charlie86 on May 19, 2018, 11:20:30 pm

Title: Bose Companion 2 series II Buzz
Post by: Charlie86 on May 19, 2018, 11:20:30 pm
Hi,

My nice Bose speakers starts buzzing even on low volume. Buzz is not really load, but loud enough to be annoying. I unplug all cables form it, and buzz is still there so it is amp itself not source.

 https://www.youtube.com/watch?v=_ai8Hhy8-JY (https://www.youtube.com/watch?v=_ai8Hhy8-JY)

Is there any easy way to fix them?

Is it possible the problem is in power supply? Hope it is because they are quite hard to disassembly.

https://www.youtube.com/watch?v=nYAj0ZpW2pc (https://www.youtube.com/watch?v=nYAj0ZpW2pc)

Title: Re: Bose Companion 2 series II Buzz
Post by: ez24 on May 20, 2018, 04:07:30 am
Quote from: Charlie86 on May 19, 2018, 11:20:30 pm
Hi,

Is it possible the problem is in power supply? Hope it is because they are quite hard to disassembly.


??  Must be the caps, FYI I also have the same problem with my Bose Roommate. 

Would you be disappointed if easy? 

Have you tried moving the AC cords?
Title: Re: Bose Companion 2 series II Buzz
Post by: Charlie86 on May 20, 2018, 07:56:47 am
Just feed them with 12v from bench power supply and buzz is still there.

Thank you Bose, to add glue on housing joins so they are pretty unrepairable.
Title: Re: Bose Companion 2 series II Buzz
Post by: Zero999 on May 20, 2018, 06:32:11 pm
It sounds like mains hum. It's interesting it doesn't go away when they were powered by a bench supply. The only other thing you could try is powering them off a battery. Note if you try this with a large lead acid battery, such as a car battery, then it must be protected by a 10A or lower rating fuse. If that doesn't work then I don't know what else to suggest.

I've heard some bad things about Bose on the Internet, regarding the general build quality and people often claim they sound inferior, yet someone I work with thinks they're great. I don't have an opinion, other than Bose are unlikely to be better or any worse than other consumer audio equipment, possibly just more expensive, due to the branding.
Title: Re: Bose Companion 2 series II Buzz
Post by: Audioguru on May 20, 2018, 10:03:01 pm
It sounds like hum picked up from the air when an input ground has a poor contact, not like power supply hum that gets into the circuit.
The Bose owner's manual says the speakers are only 2.5" in diameter and the power supply is only 12VDC/1.2A. The heatsink for the amplifiers is small so the power for each channel is about only 4W and a total of 6W creates heat.
Title: Re: Bose Companion 2 series II Buzz
Post by: Charlie86 on May 21, 2018, 05:46:32 pm
Hi,

I try to power them from 12v battery and result is the same.
Title: Re: Bose Companion 2 series II Buzz
Post by: ez24 on May 21, 2018, 07:02:16 pm
Quote from: Charlie86 on May 21, 2018, 05:46:32 pm
Hi,

I try to power them from 12v battery and result is the same.

Is this with RCA cables connected?

Are you at Diego Garcia ?

If so could this be caused by antennas (high power) ?  I used to live at a high power antenna site (I think it was closed down because of Diego Garcia) and had to place all audio equipment in Faraday cages made by lining my locker with copper screen.

So far I like the ground problem.   My problem comes and goes and so far I just deal with it but I would like a solution.


One thing about this forum is messages get "lost" very fast.  If this happens to this one - repost it with this suggested title -->  How to reduce hum in powered speakers

I am sure someone hear knows what is going on - you just have to get their attention
Title: Re: Bose Companion 2 series II Buzz
Post by: Charlie86 on May 23, 2018, 08:03:27 pm
Hi, non of cables are connected, only 12V.

No I am not from DG. And at my location are not major transponders, radars etc,..

Thanks for yours replay.