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Faint buzz from woofer when nothing physically connected to speaker

Penelinfi

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So I've just noticed a very faint ground loop style buzz coming from a woofer, only really notice it from 50cm and closer. I thought it may be seepage through the amp when turned off. It wasn't.
Unplug speaker leads from speaker - buzz still there!
I also unplugged a few powered devices in the near vicinity thinking it could be magnetic coupling from their transformers - still buzzing!
It's only from this one woofer speaker - no noise from tweeter, no noise from other speakers which are right next to it.
I'm thinking :
- Maybe magnetic coupling from power cable in that area?
- Other source of magnetic field in the area (I've noticed buzzing from this corner before, though not from a speaker)
- Reflection off of the cone - but if this was the case, I'd hear the buzz from somewhere else? Plus I was blocking the space while listening to it.

The crossover is one inductor on the woofer, notch filter on the tweeter in conjunction with first order cap, ability for bi-wire/amp, terminals currently linked, if that helps.
 

AnalogSteph

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Interesting.

Any changes with both speaker terminals shorted? Or even the woofer itself shorted directly?

You don't normally get much magnetic coupling from power cables, after all that sort of thing takes substantial loop area / inductance and there isn't much of that in twin lead. As insensitive as speaker drivers are, it would take a fairly strong magnetic field to be audible. Buzz instead of hum suggests something power supply related.

You may want to exclude the possibility of a mechanical vibration creeping in through the surface the speaker is sitting on.
 

Chrise36

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So I've just noticed a very faint ground loop style buzz coming from a woofer, only really notice it from 50cm and closer. I thought it may be seepage through the amp when turned off. It wasn't.
Unplug speaker leads from speaker - buzz still there!
I also unplugged a few powered devices in the near vicinity thinking it could be magnetic coupling from their transformers - still buzzing!
It's only from this one woofer speaker - no noise from tweeter, no noise from other speakers which are right next to it.
I'm thinking :
- Maybe magnetic coupling from power cable in that area?
- Other source of magnetic field in the area (I've noticed buzzing from this corner before, though not from a speaker)
- Reflection off of the cone - but if this was the case, I'd hear the buzz from somewhere else? Plus I was blocking the space while listening to it.

The crossover is one inductor on the woofer, notch filter on the tweeter in conjunction with first order cap, ability for bi-wire/amp, terminals currently linked, if that helps.
Do you have a router or cellphone nearby?
 
OP
Penelinfi

Penelinfi

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Buzzing stopped upon shorted terminals.
There is the power box and power line entry near to this wall section.
 

restorer-john

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Maybe the inductor/cap filter on the crossover (most likely on the rear terminal plate or lower rear of the speaker cabinet) is near the power outlet or power wiring and it's inductively coupling.

Sounds like you just made a busted-ass version of a wireless charger! ;)
 

Andysu

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it could have been buzz , fuzzing around with the electricity , make a video so we can actually hear the specific buzz on your system as buzz and buzzes , buzzing come in many forms of buzz ? even buzz is buzzled ?
buzz-aldrin-buzz.gif
 
Last edited:

wwenze

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PBF246-Bee.png

Buzzing stopped upon shorted terminals.
There is the power box and power line entry near to this wall section.

You should get an EMF meter for around $20 on aliexpress

The ideal field strength should be below 1uT

"This classification was based on pooled analyses of epidemiological studies demonstrating a consistent pattern of a two-fold increase in childhood leukaemia associated with average exposure to residential power-frequency magnetic field above 0.3 to 0.4 µT. The Task Group concluded that additional studies since then do not alter the status of this classification."
 

Chrispy

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Maybe it's like what you get when you put your ear up to a seashell....
 
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