While trying to connect wireless speakers for the Xmas season I noticed that
on the receiver end I get a distinct hmmmmmmmm. I tried different plugs
and turned off all the fluorescent lights I could find. Still there.
Also I don't think any appliances and/or chargers were functioning at the
Can some of you please suggest what other areas I might check?
Yours or neighbors cordless phones and equipment can be an issue, is
it 900mhz, alot of things use the standard frequencies, outlet wiring
and ground can have effect, try turning off all breakers to see if you
can isolate it, is it a wide plug that goes in one way, reverse the
polarity, you have to experiment, or maybe the hmm is a defect, take
it to the neighbors and try it.
Some wireless speakers aren't designed all that well, and suffer from the
very problem you describe. Even good models, as they age, begin to suffer
this problem in some cases. The electrolytic capacitor(s) used to filter the
power supply get dry and provide less filtering. Can you try running them
off a battery supply or a known good source of DV to see if they still have
the problem? This would separate your problem as being either "conducted
EMI" versus "radiated EMI". Conducted comes from the power line or power
source / power supply whereas radiated comes from fluorescent lighting or
other nearby sources of RF interference.
First connect wired speakers to your receiver and check for a hum. This is a
common, but tricky to diagnose, problem in audio systems. If your amp has a
hum that is heard through wired speakers, it is a ground loop problem. This
is caused by multiple groundings. Only one source of ground is recommended
as a loop is formed when multiple items are interconnected while plugged
into grounded outlets, this includes the grounded sheath of "cable TV"
cabling. Only the amp should be grounded all other equipment should not be
grounded. A grounded "cable TV" cable may need an isolation device added in
line with the cable.
If you have no hum through wired speakers, then it is the wireless system
picking up the hum or the circuitry is creating the hum.
Light dimmers are a possible source.
It's also possible the origin, whatever it may be, isn't even on your
Old wireless 'AM' intercoms were notorious for picking up 60Hz hum's.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.