Bose companion 5 acoustimass module very loud buzzing sound

few months before small amount of noises and buzzing sound. it stops after a while. now after switching on power immediately very loud buzzing starts. even I tried out only the bass module, removing all other cables,  it continues. the noise is completely extreme. no bass wen the system is on with noise. 

Hello smtaufik92, 


Thanks for posting. 


I'm sorry to hear you're having issues with your Companion 5 speaker. 


You mentioned the buzzing occurs even if no other cables are connected to the bass module. This certainly shouldn't be happening. Have you tried plugging the system in via a different power outlet? Have you also tried using another power cord? 


I'll look forward to your reply!

It was stopped for 6 months….den when I wanna bang loud ….the bass module was extremely  buzzzing :(. It was a horror moment. I tried all steps avobe. Even I was so mad I was trying reboot  the speaker by a 30 sec power off. :(. This speaker is a emotion.  I purchased it from USA while Im completing my cadetship training onboard. Then fly over all the way from Texas to Bangladesh. Actually Im in love with Bose . Actually the orginal home of late Amar Bose (R I P) was  in my place. So its a emotional engineering thing. So please help me if you can, to save my 1st Emotion of Bose. 

Look How Frausted Im commenting on my  own question. One thing I missed which was so important I guess…Im using a stepdown transformer.

power rated as 1000VA.

Input : 220V~110V

Output: 1OO~120V

Rated frequency : 50/60Hz

but previously there a no such a problem xcept that minor humming.


Thanks for getting back in touch. 


We generally do not recommend the usage of stepdown transformers as performance of the product can be unpredictable. The buzzing you've noted may be directly related to the usage of the transformer. The Companion 5 (US variant) is a 120v system, so shouldn't be used with voltages of a higher output. 


If the problem persists, you may wish to get in touch with local support to discuss a repair and also the possibility of a voltage conversion if it is something the team can offer.