Strange speaker noise

[Turtleherder]

Hi all, I'm new hear and looking for some trouble shooting advise. Usually I'm over at one of the sister sites, Roadbikereview. Anyway, last night I was re foaming a woofer from a set of older three way speakers. I had the woofer out and the speaker was flat on it's back, not connected to any source, and I noticed that the Vifa midrange was making a very faint buzzing noise. I thought I was crazy, but my wife also heard it.

So how can it be carrying a signal if it's not connected to anything? Does my house have that much stray interference flowing everywhere to power a non powered speaker? And if so, what is it doing to my primary system, and can I stop it? I should note that there was a small dorm sized refrigerator in the same room about 15 feet away.

So, anyone know what could be going on here?

[Luvin Da Blues]

I think that the "mechanical" vibrations from the fridge is being induced into the speakers' cone. Since the cone is vibrating it's producing a sound. Just a thought.

[Rich-n-Texas]

That might be the case LDB as long as the refridgerator's compressor was running at the time he heard the noise.

Turtleherder (that's a funny one), you're saying you had the woofer out but the Vifa midrange was making a noise. You're not saying whether or not the Vifa midrange was connected.

[cloudy9]

Yah.. Kindly specify it. So that we can easily give you a troubleshooting advice for your speaker.

[Turtleherder]

After reading some of the responses here I checked again. The way the speaker sits now, the woofer is out of the cabinet on the floor. The cabinet is flat on it's back, face up. No speaker wire is connected but all the individual drivers are still wired in.

When the compressor in the refrigerator is running the mid range buzzes. When the refrigerator is not running the mid range is quiet.

So do you think that the frig compressor is putting out enough radio interference to produce a signal, through the air, to make the midrange react? I can't think of what else it could be and maybe I need to get rid of the frig.


/ The turtleherder name came from my wife because in the summer I will stop and move the turtles off the road so they won't be squished.

[Rich-n-Texas]

Okay. I think aliens are getting ready to land on your house so you should put the speaker down and HEAD FOR THE HILLS!!! :smilewinkgrin:

The fridge compressor, in my opinion could very well be putting out a frequency that resonates with a speaker and causes it to buzz. Make sure your fridge is grounded, and also try plugging it into a different outlet. Are you saying the dorm size refridgerator is still in the same room?

[Turtleherder]

Okay. I think aliens are getting ready to land on your house so you should put the speaker down and HEAD FOR THE HILLS!!! :smilewinkgrin:

The fridge compressor, in my opinion could very well be putting out a frequency that resonates with a speaker and causes it to buzz. Make sure your fridge is grounded, and also try plugging it into a different outlet. Are you saying the dorm size refrigerator is still in the same room?

The dorm size frig (beer fridge) sits on a rack in the corner of the room and is plugged into a grounded outlet. The speaker I was working on was on the carpeted floor about 10 feet away. It's not mechanical resonance, as in vibration through the floor, it definitely sounds electrical through the speaker. I will try a different outlet and see if that does anything.

Maybe it is aliens or Nikola Tesla back from beyond the grave. Like I said I have never heard of an unconnected speaker actually producing a signal. And if it really is the frig I want to take it out of the electrical paths of my house because I have no idea what it could be doing to my main system upstairs.

[Rich-n-Texas]

To completely eliminate the potential interference that the fridge may be causing, I think you should send it to me, contents intact. :thumbsup:

It sure would be nice to get some opinions from other people here, in the event I'm way off base...

[kexodusc]

After reading some of the responses here I checked again. The way the speaker sits now, the woofer is out of the cabinet on the floor. The cabinet is flat on it's back, face up. No speaker wire is connected but all the individual drivers are still wired in.

When the compressor in the refrigerator is running the mid range buzzes. When the refrigerator is not running the mid range is quiet.

So do you think that the frig compressor is putting out enough radio interference to produce a signal, through the air, to make the midrange react? I can't think of what else it could be and maybe I need to get rid of the frig.


/ The turtleherder name came from my wife because in the summer I will stop and move the turtles off the road so they won't be squished.
Could very well be the vibrations from the fridge, but if the woofer is still connected to the system, then there could be some voltage generated just from the other drivers in the speaker....basically acting like a microphone would - the speaker motor is just a voice coil wrapped around a magnet, so any movement of those motors could be sending some current back through the speaker system...does the vifa vibrate if it's disconnected from the rest of the speaker?

It's pretty odd that a fridge vibration would excite a speaker in suspension, but maybe it's a perfect combination of frequency of resonance and energy?

All just speculation on my part...