(if there are any Buzzcocks fans out there, my Festool Hat's off to
you)
I always thought my planer was much louder when the dust collector was
running so I borrowed a sound level meter from work to verify it
quantitatively . Standing at a location where you would be feeding
stock into the planer (15 inch Delta, Chinese made) I first measured
the sound with just the planer motor on and no DC running and got
85db. With the planer off I then opened the 5 inch blast gate and
turned on the DC (3hp Oneida) which resides in a separate room and
runs from 7 to 6 to a final 5 inch diameter pipe at the planer. The
sound level was 82db. With the DC on I turned on the planer and
measured 106db. Planing 4 inch wide oak - light cuts - only increased
the sound level to 108db.
With the planer still under power I truned off the DC and watched as
the level decreased slowly to 85 again. I cycled the DC once more
just to repeat the readings and it was as before.
I never gave it much thought but it seems like you can suck the sound
out of a machine. I know very little about sound technology but I am
aware that the db range is logarithmic however I don't know how to
calculate what occurred. I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. Any sound experts reading this? Thanks for any
feedback.

Marc

On 4/2/2012 8:13 PM, marc rosen wrote:

calculate what occurred. I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. Any sound experts reading this? Thanks for any
feedback.

Adding two identical sound sources can indeed increase the sound power
level significantly.

There a few other possibilities, one being the result of standing waves
due to acoustic "nodes" in the shop room itself. Try moving the
instrument to another location in the room and see if you get the same
results.

Check out the SPL calculator he

http://www.engineeringtoolbox.com/ad...ibel-d_63.html

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 4/2/12 9:59 PM, Swingman wrote:
http://www.engineeringtoolbox.com/ad...ibel-d_63.html


Where has this site been all my life!?


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

-MIKE- wrote:
On 4/2/12 9:59 PM, Swingman wrote:
http://www.engineeringtoolbox.com/ad...ibel-d_63.html


Where has this site been all my life!?

They also have some handy Sketchup engineering models.
--
www.ewoodshop.com

On Apr 2, 10:59*pm, Swingman wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

calculate what occurred. *I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. *Any sound experts reading this? *Thanks for any
feedback.

Adding two identical sound sources can indeed increase the sound power
level significantly.

There a few other possibilities, one being the result of standing waves
due to acoustic "nodes" in the shop room itself. Try moving the
instrument to another location in the room and see if you get the same
results.

Hi Swing,
Thanks for the link and the comment. I did not measure the sound at
different locations but I have listened to it throughout my shop and
the living room area above. In all cases the sounds produced by
either the DC or the planer are insignificant. But turn them both on
and it is an unpleasant level.

Marc

On 4/2/2012 9:59 PM, Swingman wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

calculate what occurred. I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. Any sound experts reading this? Thanks for any
feedback.

Adding two identical sound sources can indeed increase the sound power
level significantly.

There a few other possibilities, one being the result of standing waves
due to acoustic "nodes" in the shop room itself. Try moving the
instrument to another location in the room and see if you get the same
results.

Check out the SPL calculator he

http://www.engineeringtoolbox.com/ad...ibel-d_63.html


I get the same increase in sound from my Delta 15" planer when I turn on
the DC.

On 4/3/2012 6:34 AM, marc rosen wrote:
On Apr 2, 10:59 pm, wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

calculate what occurred. I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. Any sound experts reading this? Thanks for any
feedback.

Adding two identical sound sources can indeed increase the sound power
level significantly.

There a few other possibilities, one being the result of standing waves
due to acoustic "nodes" in the shop room itself. Try moving the
instrument to another location in the room and see if you get the same
results.

Hi Swing,
Thanks for the link and the comment. I did not measure the sound at
different locations but I have listened to it throughout my shop and
the living room area above. In all cases the sounds produced by
either the DC or the planer are insignificant. But turn them both on
and it is an unpleasant level.

Marc

I have the same set up and agree that the sound significantly increases
in volume. I wonder if a jointer would show the same increase.

On 4/3/2012 6:34 AM, marc rosen wrote:
On Apr 2, 10:59 pm, wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

calculate what occurred. I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. Any sound experts reading this? Thanks for any
feedback.

Adding two identical sound sources can indeed increase the sound power
level significantly.

There a few other possibilities, one being the result of standing waves
due to acoustic "nodes" in the shop room itself. Try moving the
instrument to another location in the room and see if you get the same
results.

Hi Swing,
Thanks for the link and the comment. I did not measure the sound at
different locations but I have listened to it throughout my shop and
the living room area above. In all cases the sounds produced by
either the DC or the planer are insignificant. But turn them both on
and it is an unpleasant level.

IME, there at least a couple of things at play.

Each motor is producing varying frequencies which, when they coincide
with the other motor, the perceived intensity of those frequencies is
increased, either by adding together, or by exciting a resonance in the
room at those frequencies (think of a drum), or both.

In addition, and since loudness is actually perceived by the firing of
nerves, and the number of nerves, in different areas of the ears, with
both motors running and producing sound waves at their varying
frequencies, many more nerves are firing in your ears, which will also
result in an increase in perceived loudness.

And example would be in a symphony ... a section of ten violins playing
the same note will generally sound twice as loud as one violin. But ten
different instruments playing in harmony (different frequencies) at the
same time will sound more than twice as loud as any individual instrument.

From your description, most likely a combination of the above is what
is causing the phenomenon you are describing.

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

"Swingman" wrote in message
...
On 4/3/2012 6:34 AM, marc rosen wrote:
On Apr 2, 10:59 pm, wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

So.... is it possible to develop noise cancelling sound for the shop? This
along the lines of the noise cancelling systems in car audio systems?

John

The most likely cause of the increase is the airflow within the planer. If
your Delta is like mine the dust collector hood has a 4 inch round opening
for the hose and a narrow wide slit that attaches to the planer to suck up
the chips. Pulling your dust collector airflow thru the slit will produc
noise on its own. Sort of like blowing over the top of a soda bottle.

Russ
"marc rosen" wrote in message
...
(if there are any Buzzcocks fans out there, my Festool Hat's off to
you)
I always thought my planer was much louder when the dust collector was
running so I borrowed a sound level meter from work to verify it
quantitatively . Standing at a location where you would be feeding
stock into the planer (15 inch Delta, Chinese made) I first measured
the sound with just the planer motor on and no DC running and got
85db. With the planer off I then opened the 5 inch blast gate and
turned on the DC (3hp Oneida) which resides in a separate room and
runs from 7 to 6 to a final 5 inch diameter pipe at the planer. The
sound level was 82db. With the DC on I turned on the planer and
measured 106db. Planing 4 inch wide oak - light cuts - only increased
the sound level to 108db.
With the planer still under power I truned off the DC and watched as
the level decreased slowly to 85 again. I cycled the DC once more
just to repeat the readings and it was as before.
I never gave it much thought but it seems like you can suck the sound
out of a machine. I know very little about sound technology but I am
aware that the db range is logarithmic however I don't know how to
calculate what occurred. I'm sure the sound produced by the
combination of planer and DC is greater than the additive effect of
each device. Any sound experts reading this? Thanks for any
feedback.

Marc

On 4/3/2012 8:08 AM, John Grossbohlin wrote:

"Swingman" wrote in message
...
On 4/3/2012 6:34 AM, marc rosen wrote:
On Apr 2, 10:59 pm, wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

So.... is it possible to develop noise cancelling sound for the shop?
This along the lines of the noise cancelling systems in car audio systems?

In theory, yes. Practically ... easier, and cheaper to stick with ear
muffs.

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 4/3/2012 8:20 AM, Russ Stanton wrote:
The most likely cause of the increase is the airflow within the planer. If your
Delta is like mine the dust collector hood has a 4 inch round opening for the
hose and a narrow wide slit that attaches to the planer to suck up the chips.
Pulling your dust collector airflow thru the slit will produc noise on its own.
Sort of like blowing over the top of a soda bottle.

Well sorta. I have a 15" Grizzly planer and a Grizzly cyclone, and the planer
makes a LOT more noise when the dust collector comes on. The collector pulls a
*considerable* amount of air past the planer knives, and those rapidly spinning
knives will make a huge whirring noise as they "cut" through that high-speed
flow of air. Any fan or propeller is going to make a quite a bit of wind noise
at high speed, but planer blades are far less aerodynamic so the noise is much
greater.

I'm curious to hear what the noise factor might be on a planer that has the
network of spiral cutters rather than full length knives. I'll bet they are
much quieter.

--
Free bad advice available here.
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/

On 4/3/2012 8:20 AM, Russ Stanton wrote:

The most likely cause of the increase is the airflow within the planer.
If your Delta is like mine the dust collector hood has a 4 inch round
opening for the hose and a narrow wide slit that attaches to the planer
to suck up the chips. Pulling your dust collector airflow thru the slit
will produc noise on its own. Sort of like blowing over the top of a
soda bottle.

That doesn't explain the additive nature of the increase with two
machines running, neither one being louder than the other, which I think
is what his question was ... could have misunderstood the original question


--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

"Swingman" wrote in message
...
On 4/3/2012 8:08 AM, John Grossbohlin wrote:

"Swingman" wrote in message
...
On 4/3/2012 6:34 AM, marc rosen wrote:
On Apr 2, 10:59 pm, wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

So.... is it possible to develop noise cancelling sound for the shop?
This along the lines of the noise cancelling systems in car audio
systems?

In theory, yes. Practically ... easier, and cheaper to stick with ear
muffs.


Maybe for you or me... but there are folks out there that would buy it. ;~)

John

On 4/3/2012 8:53 AM, Swingman wrote:
On 4/3/2012 8:20 AM, Russ Stanton wrote:

The most likely cause of the increase is the airflow within the planer.
If your Delta is like mine the dust collector hood has a 4 inch round
opening for the hose and a narrow wide slit that attaches to the planer
to suck up the chips. Pulling your dust collector airflow thru the slit
will produc noise on its own. Sort of like blowing over the top of a
soda bottle.

That doesn't explain the additive nature of the increase with two
machines running, neither one being louder than the other, which I think
is what his question was ... could have misunderstood the original question



Could the hose be acting as a megaphone?

On 4/3/12 11:03 AM, Leon wrote:
On 4/3/2012 8:53 AM, Swingman wrote:
On 4/3/2012 8:20 AM, Russ Stanton wrote:

The most likely cause of the increase is the airflow within the planer.
If your Delta is like mine the dust collector hood has a 4 inch round
opening for the hose and a narrow wide slit that attaches to the planer
to suck up the chips. Pulling your dust collector airflow thru the slit
will produc noise on its own. Sort of like blowing over the top of a
soda bottle.

That doesn't explain the additive nature of the increase with two
machines running, neither one being louder than the other, which I think
is what his question was ... could have misunderstood the original
question



Could the hose be acting as a megaphone?

Might want to check everything for Oak Rust©.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On Tue, 3 Apr 2012 09:08:22 -0400, "John Grossbohlin"
wrote:


"Swingman" wrote in message
...
On 4/3/2012 6:34 AM, marc rosen wrote:
On Apr 2, 10:59 pm, wrote:
On 4/2/2012 8:13 PM, marc rosen wrote:

So.... is it possible to develop noise cancelling sound for the shop? This
along the lines of the noise cancelling systems in car audio systems?

Quite possible all it takes is money.

Mark