All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

Patrick Duley wrote:

All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley


It's probably RFI. Computer monitors ( CRT type ) Radiate all kinds of RF
trash at many frequencies. The speakers by themselves should not pick up this
RFI, but if the speakers have internal amplifiers, the amplifiers will pick up
and
amplify this noise. Where is the amplifier for these speakers, and can you
move it further away from the monitor? Just a foot or two should be enough.
Go to your local electronics supply place and buy some clamp on ferrites to
put on the power cable, and signal cable(s) feeding the amp. These will help
as well. Check the ground path. Make sure that the ground connection from
the monitor to the wall is good, and that the ground connection in the wall plug

is good. Buy signal cables that have better shielding on them.

--Dale

Patrick Duley wrote:

All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley


It's probably RFI. Computer monitors ( CRT type ) Radiate all kinds of RF
trash at many frequencies. The speakers by themselves should not pick up this
RFI, but if the speakers have internal amplifiers, the amplifiers will pick up
and
amplify this noise. Where is the amplifier for these speakers, and can you
move it further away from the monitor? Just a foot or two should be enough.
Go to your local electronics supply place and buy some clamp on ferrites to
put on the power cable, and signal cable(s) feeding the amp. These will help
as well. Check the ground path. Make sure that the ground connection from
the monitor to the wall is good, and that the ground connection in the wall plug

is good. Buy signal cables that have better shielding on them.

--Dale

Dale,

Thanks for the advice.

I put two ferrite choke cores on the receiver power supply cord but it
didn't have any impact.

The speakers are not amplified- I thought it might be hum induced into the
speaker drivers themselves because the hum is significantly reduced when I
place a cookie sheet between the monitor and speakers.

Maybe I just need a couple of fashionable cookie sheets to add to the decor!

Thanks again,
Patrick



"Dale Farmer" wrote in message
...


Patrick Duley wrote:

All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer
monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40)
is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive
Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley


It's probably RFI. Computer monitors ( CRT type ) Radiate all kinds of
RF
trash at many frequencies. The speakers by themselves should not pick up
this
RFI, but if the speakers have internal amplifiers, the amplifiers will
pick up
and
amplify this noise. Where is the amplifier for these speakers, and can
you
move it further away from the monitor? Just a foot or two should be
enough.
Go to your local electronics supply place and buy some clamp on ferrites
to
put on the power cable, and signal cable(s) feeding the amp. These will
help
as well. Check the ground path. Make sure that the ground connection
from
the monitor to the wall is good, and that the ground connection in the
wall plug

is good. Buy signal cables that have better shielding on them.

--Dale

Dale,

Thanks for the advice.

I put two ferrite choke cores on the receiver power supply cord but it
didn't have any impact.

The speakers are not amplified- I thought it might be hum induced into the
speaker drivers themselves because the hum is significantly reduced when I
place a cookie sheet between the monitor and speakers.

Maybe I just need a couple of fashionable cookie sheets to add to the decor!

Thanks again,
Patrick



"Dale Farmer" wrote in message
...


Patrick Duley wrote:

All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer
monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40)
is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive
Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley


It's probably RFI. Computer monitors ( CRT type ) Radiate all kinds of
RF
trash at many frequencies. The speakers by themselves should not pick up
this
RFI, but if the speakers have internal amplifiers, the amplifiers will
pick up
and
amplify this noise. Where is the amplifier for these speakers, and can
you
move it further away from the monitor? Just a foot or two should be
enough.
Go to your local electronics supply place and buy some clamp on ferrites
to
put on the power cable, and signal cable(s) feeding the amp. These will
help
as well. Check the ground path. Make sure that the ground connection
from
the monitor to the wall is good, and that the ground connection in the
wall plug

is good. Buy signal cables that have better shielding on them.

--Dale

This can be caused by a number of things. If the speakers have a built in
amplifier, it can be picking up some of the RF radiation from the scans,
high voltage supply, and power supply.

In many monitors the induced radiated magnetic field can be strong enough to
radiate to the speakers directly. Placement of the speakers to a farther
distance from the monitor is the best solution. You can try a metal shield
that is of a Ferris composite metal and see if this will do the job. The
size will have to be large enough. Also, it should be done in many layers.
This type of shielding is not easy to do, and is not cheap to do, if using
the proper type of metal.

The very best solution is to invest in an LCD screen. There will be very
little RF radiation, and no induced magnetic fields. LCD panels have almost
no UV radiation, and no flicker. Therefore you will not have anymore
eyesore, or fatigue when working on it for many hours.

As for long term health risks, there is no X-Ray radiation from LCD panels.
The radiation from CRT type monitors is very controversial, even though it
is at a low level, and complies to the international safety standards. But,
any amount of radiation is not good for living tissues.

In our work place where we do our service and support contracts, we only use
LCD panels. We found that the employee production increased by over 20%
over the long term. They are taking less breaks from eye fatigue, and also
there are less sick days. Now go figure this out...

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Patrick Duley" wrote in message
k.net...
All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

This can be caused by a number of things. If the speakers have a built in
amplifier, it can be picking up some of the RF radiation from the scans,
high voltage supply, and power supply.

In many monitors the induced radiated magnetic field can be strong enough to
radiate to the speakers directly. Placement of the speakers to a farther
distance from the monitor is the best solution. You can try a metal shield
that is of a Ferris composite metal and see if this will do the job. The
size will have to be large enough. Also, it should be done in many layers.
This type of shielding is not easy to do, and is not cheap to do, if using
the proper type of metal.

The very best solution is to invest in an LCD screen. There will be very
little RF radiation, and no induced magnetic fields. LCD panels have almost
no UV radiation, and no flicker. Therefore you will not have anymore
eyesore, or fatigue when working on it for many hours.

As for long term health risks, there is no X-Ray radiation from LCD panels.
The radiation from CRT type monitors is very controversial, even though it
is at a low level, and complies to the international safety standards. But,
any amount of radiation is not good for living tissues.

In our work place where we do our service and support contracts, we only use
LCD panels. We found that the employee production increased by over 20%
over the long term. They are taking less breaks from eye fatigue, and also
there are less sick days. Now go figure this out...

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Patrick Duley" wrote in message
k.net...
All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

Jerry,

Would the "aluminum constraining layer" of the
http://www.b-quiet.com/extreme.html solution meet the requirement of your
"ferris composite metal".

I hope you say yes since I've already ordered $40 of this stuff.

If not, what do you recommend?

The LCD is last if I can't fix the problem inexpensively.

Thanks,
Patrick



"Jerry G." wrote in message
...
This can be caused by a number of things. If the speakers have a built in
amplifier, it can be picking up some of the RF radiation from the scans,
high voltage supply, and power supply.

In many monitors the induced radiated magnetic field can be strong enough
to
radiate to the speakers directly. Placement of the speakers to a farther
distance from the monitor is the best solution. You can try a metal shield
that is of a Ferris composite metal and see if this will do the job. The
size will have to be large enough. Also, it should be done in many layers.
This type of shielding is not easy to do, and is not cheap to do, if using
the proper type of metal.

The very best solution is to invest in an LCD screen. There will be very
little RF radiation, and no induced magnetic fields. LCD panels have
almost
no UV radiation, and no flicker. Therefore you will not have anymore
eyesore, or fatigue when working on it for many hours.

As for long term health risks, there is no X-Ray radiation from LCD
panels.
The radiation from CRT type monitors is very controversial, even though it
is at a low level, and complies to the international safety standards.
But,
any amount of radiation is not good for living tissues.

In our work place where we do our service and support contracts, we only
use
LCD panels. We found that the employee production increased by over 20%
over the long term. They are taking less breaks from eye fatigue, and
also
there are less sick days. Now go figure this out...

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Patrick Duley" wrote in message
k.net...
All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer
monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

Jerry,

Would the "aluminum constraining layer" of the
http://www.b-quiet.com/extreme.html solution meet the requirement of your
"ferris composite metal".

I hope you say yes since I've already ordered $40 of this stuff.

If not, what do you recommend?

The LCD is last if I can't fix the problem inexpensively.

Thanks,
Patrick



"Jerry G." wrote in message
...
This can be caused by a number of things. If the speakers have a built in
amplifier, it can be picking up some of the RF radiation from the scans,
high voltage supply, and power supply.

In many monitors the induced radiated magnetic field can be strong enough
to
radiate to the speakers directly. Placement of the speakers to a farther
distance from the monitor is the best solution. You can try a metal shield
that is of a Ferris composite metal and see if this will do the job. The
size will have to be large enough. Also, it should be done in many layers.
This type of shielding is not easy to do, and is not cheap to do, if using
the proper type of metal.

The very best solution is to invest in an LCD screen. There will be very
little RF radiation, and no induced magnetic fields. LCD panels have
almost
no UV radiation, and no flicker. Therefore you will not have anymore
eyesore, or fatigue when working on it for many hours.

As for long term health risks, there is no X-Ray radiation from LCD
panels.
The radiation from CRT type monitors is very controversial, even though it
is at a low level, and complies to the international safety standards.
But,
any amount of radiation is not good for living tissues.

In our work place where we do our service and support contracts, we only
use
LCD panels. We found that the employee production increased by over 20%
over the long term. They are taking less breaks from eye fatigue, and
also
there are less sick days. Now go figure this out...

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Patrick Duley" wrote in message
k.net...
All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer
monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

Aluminum is non-ferrous.

Kal

On Tue, 28 Oct 2003 02:31:07 GMT, "Patrick Duley"
wrote:

Jerry,

Would the "aluminum constraining layer" of the
http://www.b-quiet.com/extreme.html solution meet the requirement of your
"ferris composite metal".

I hope you say yes since I've already ordered $40 of this stuff.

If not, what do you recommend?

The LCD is last if I can't fix the problem inexpensively.

Thanks,
Patrick



"Jerry G." wrote in message
...
This can be caused by a number of things. If the speakers have a built in
amplifier, it can be picking up some of the RF radiation from the scans,
high voltage supply, and power supply.

In many monitors the induced radiated magnetic field can be strong enough
to
radiate to the speakers directly. Placement of the speakers to a farther
distance from the monitor is the best solution. You can try a metal shield
that is of a Ferris composite metal and see if this will do the job. The
size will have to be large enough. Also, it should be done in many layers.
This type of shielding is not easy to do, and is not cheap to do, if using
the proper type of metal.

The very best solution is to invest in an LCD screen. There will be very
little RF radiation, and no induced magnetic fields. LCD panels have
almost
no UV radiation, and no flicker. Therefore you will not have anymore
eyesore, or fatigue when working on it for many hours.

As for long term health risks, there is no X-Ray radiation from LCD
panels.
The radiation from CRT type monitors is very controversial, even though it
is at a low level, and complies to the international safety standards.
But,
any amount of radiation is not good for living tissues.

In our work place where we do our service and support contracts, we only
use
LCD panels. We found that the employee production increased by over 20%
over the long term. They are taking less breaks from eye fatigue, and
also
there are less sick days. Now go figure this out...

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Patrick Duley" wrote in message
k.net...
All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer
monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

Aluminum is non-ferrous.

Kal

On Tue, 28 Oct 2003 02:31:07 GMT, "Patrick Duley"
wrote:

Jerry,

Would the "aluminum constraining layer" of the
http://www.b-quiet.com/extreme.html solution meet the requirement of your
"ferris composite metal".

I hope you say yes since I've already ordered $40 of this stuff.

If not, what do you recommend?

The LCD is last if I can't fix the problem inexpensively.

Thanks,
Patrick



"Jerry G." wrote in message
...
This can be caused by a number of things. If the speakers have a built in
amplifier, it can be picking up some of the RF radiation from the scans,
high voltage supply, and power supply.

In many monitors the induced radiated magnetic field can be strong enough
to
radiate to the speakers directly. Placement of the speakers to a farther
distance from the monitor is the best solution. You can try a metal shield
that is of a Ferris composite metal and see if this will do the job. The
size will have to be large enough. Also, it should be done in many layers.
This type of shielding is not easy to do, and is not cheap to do, if using
the proper type of metal.

The very best solution is to invest in an LCD screen. There will be very
little RF radiation, and no induced magnetic fields. LCD panels have
almost
no UV radiation, and no flicker. Therefore you will not have anymore
eyesore, or fatigue when working on it for many hours.

As for long term health risks, there is no X-Ray radiation from LCD
panels.
The radiation from CRT type monitors is very controversial, even though it
is at a low level, and complies to the international safety standards.
But,
any amount of radiation is not good for living tissues.

In our work place where we do our service and support contracts, we only
use
LCD panels. We found that the employee production increased by over 20%
over the long term. They are taking less breaks from eye fatigue, and
also
there are less sick days. Now go figure this out...

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Patrick Duley" wrote in message
k.net...
All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer
monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley

All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley



Speaker shielding does not protect the speakers from induced hum, it protects
the CRT from speaker magnetic fields.

If your CRT is putting out that much hash, move the speakers away from it.

You might consider another CRT, or aflat panel monitor.

A large steel plate or Mu-Metal between the speakers and the CRT may deflect
the signal, but I doubt it.

Frost King insulation or aluminum foil will do nothing.
Richard H. Kuschel
"I canna change the law of physics."-----Scotty

All,

I have a pair of PSB Alpha-Mini speakers setup beside a 17" computer monitor
(only 1-2" clearance). According to the manufacturer's literature the
Alpha-Minis are shielded.

There is an audible buzz or hum from the speakers when the monitor is
powered on. The buzz is present whether or not the receiver (NAD L40) is
powered on.

Is this buzz likely due to inadequate shielding of the speaker drivers?

Is it possible to add additional shielding to the speakers?

I was thinking about using something like this:
http://www.b-quiet.com/extreme.html or Frost King Self-Adhesive Foil/Foam
Duct Insulation bonded to the interior walls of the speakers.

Would this work or am I off-base? Any advice appreciated.

Thanks,
Patrick Duley



Speaker shielding does not protect the speakers from induced hum, it protects
the CRT from speaker magnetic fields.

If your CRT is putting out that much hash, move the speakers away from it.

You might consider another CRT, or aflat panel monitor.

A large steel plate or Mu-Metal between the speakers and the CRT may deflect
the signal, but I doubt it.

Frost King insulation or aluminum foil will do nothing.
Richard H. Kuschel
"I canna change the law of physics."-----Scotty