Cause of 'whooshing' sound

[Bennett]

I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance

 

[mike]

On 4/30/2013 4:39 PM, Bennett wrote:

I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance
I'd put an oscilloscope on the power supply.

 

[Jamie]

Bennett wrote:

I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance
Some times a zorc circuit is placed at the output to halt possible

oscillation that can take place.

This usually consist of a capacitor and R in series.. optimized to
react at higher frequencies to maintain a lower lever of output Z.

Some amp circuits will go into oscillation with out this circuit and
you can hear all kinds of effects.


Jamie

 

[N_Cook]

mike <ham789@netzero.net> wrote in message
news:klpkpt$gks$2@dont-email.me...

On 4/30/2013 4:39 PM, Bennett wrote:
I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance
I'd put an oscilloscope on the power supply.

low voltages side of the power supply , initially anyway.

I would suspect a grounding/earthing problem .
If it is present most of the time , locally heat or cool different areas to
see if the character of the noise changes.
IS this a "sound bar" DSP type of amp for throwing stereo from one speaker
box, then a DSP failure?

 

[N_Cook]

I assume the problem is present with proper inputs connected. What nearby RF
sources are there , wifi, bluetooth, other kit with SMPSs etc. Does moving
any of those sources relative to the amp change the noise character. Or try
the amp in another room as a diagnostic approach

 

[Bennett]

On 4/30/2013 4:39 PM, Bennett wrote:

I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance

Thanks to all who've replied. This isn't a DSP and/or soundbar device
and definitely is not picking up RF from elsewhere. The 'whoosh' is
present with or without input cables connected.

 

[N_Cook]

Bennett <bjprice@cal.berkeley.edu> wrote in message
news:2bCdna_GyYYb3hzMnZ2dnUVZ5h2dnZ2d@giganews.com...

On 4/30/2013 4:39 PM, Bennett wrote:
I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance

Thanks to all who've replied. This isn't a DSP and/or soundbar device
and definitely is not picking up RF from elsewhere. The 'whoosh' is
present with or without input cables connected.

Assuming its safe to short an input to ground , is the defect still present
then?

 

[Bennett]

On 5/3/2013 9:28 AM, N_Cook wrote:

Bennett <bjprice@cal.berkeley.edu> wrote in message
news:2bCdna_GyYYb3hzMnZ2dnUVZ5h2dnZ2d@giganews.com...
On 4/30/2013 4:39 PM, Bennett wrote:
I've got a Creative PC speaker, woofer and 5 tweeters. With inputs
disconnected I get a sort of intermittent whooshing or wind like sound.
The volume of the sound is not controlled by the unit's volume control.

Since this is coming from all the speakers, I assume - correctly? - that
the built in power supply is acting up. I assume the built in power
supply is some sort of switcher - would bad caps cause this noise?

Where else should I look. Thanks in advance

Thanks to all who've replied. This isn't a DSP and/or soundbar device
and definitely is not picking up RF from elsewhere. The 'whoosh' is
present with or without input cables connected.


Assuming its safe to short an input to ground , is the defect still present
then?


Yes