Good morning

I recently purchased 2 x Forcefield 4 subs from a friend of mine for e dedicated listening room. I am very satisfied with the integration and they really sound fantastic. A week ago I noticed a humm or buzz coming from one of the subs when no music played. This buzz appeared suddenly and my wife pointed it out as well without mentioning it to her. I listened to the other sub and I could hear the same buzz but a third of the volume compared to the other sub. The buzz can be heard while playing music as well at low volumes. I started faultfinding and did the follwing:

* I removed the input (rca) to the sub but the humm was still present
* The buzz is not changing when I change the volume or cut off frequency potentiometers
* I changed the power cord but the buzz remained
* I moved the power chord to the same multi plug as the amplifier with no improvement
* I took the sub (worst sub) to a friend and work to test them on different power grids but the buzz was still present
* I measured the buzz to peak at 149 Hz with a downloaded sound spectrum analyzer for android
* Note our grid frequency is 50hz which makes me believe the 149Hz could be a power supply fault.

Has anyone else experience this buzz from their forcefield 4 subs? Are there any more tests I can do to find the problem?

Note that we do have power cuts in South Africa and the grid power is unstable at times. My music system is connected to a surge protection device at all times but I know it is possible for any spike to still get pass these protectors. I haven't had problems with any of my other appliances. My next step would be to open the units and measure the voltage out of the DC rectifier with an oscilloscope to see if the ~150Hz buzz could be coming from that. Any advise would help.

Fantastic SUBS otherwise

Thank you

Jakes

Hi Jakes, It certainly seems like the amplifier built-into this ForceField 4 subwoofer is defective and needs to serviced. I would recommend contacting GoldenEar's customer service department at This email address is being protected from spambots. You need JavaScript enabled to view it.. They can go over your service options.

Thank you. I sent them an email