Tool Noise Levels

[LCHIEN]

I put this in a topic of its own so it could be searched for.
Tool Noise levels:

HF 2HP DC with port open: 90 dB SPL
DC with one port closed, one 4" port to Table saw: 88 dBSPL

Shop Vac (6 Gal) 94 dBSPL

BT3000 running, not cutting, DC off: 90 dBSPL
BT3000 cutting (Ripping 3/4" softwood), DC off: 92 dBSPL

Miter Saw 10" not cutting: 92 dBSPL
Miter Saw 10" cutting 2x4 105-109 dBSPL (ouch!)

Bosch 1617evspk router mounted in table:
idling full RPM: 96 dBSPL
Cutting 1/2" straight carbide spiral bit 1/4" deep dado in cedar: 100 dBSPL

delta 12" benchtop DP 1100 RPM: 68 dBSPL
Hitachi 15" floorstanding DP 990 RPM: 64 dBSPL

Delta 50-860 Air cleaner 800 CFM: 68 dBSPL


Radio Shack 33-2055 sound level meter, C-Weighted, at a distance of 1 meter from tool.

Remember that every <s>+3dB </s> +10 dB sounds twice as loud to humans.
But I do agree that the shop vac is much more shrill-sounding because of the pitch.

With the DC plumbed up it was probably moving a little less air and more likely the rushing air noise was moved to the saw ten feet away which is why it was a couple of dB lower.

So the Shop vac sounds about 6dB louder than the DC.

P.S. Zich was right
P.P.S. Added router levels 2/11/06
P.P.S. Added drill press and air cleaner 2/15/06

[Zich]

Small clarification... 3dB equals a doubling of the sound pressure, but 10dB is a doubling in the perceived sound level by humans.

[wassaw998]

Thanks Loring, very useful information.

Wonder how the newer (advertised quieter) Shop Vacs come out? I recently picked up a 5.5Hp Contractors unit, and it is definitely a LOT quieter then my old Craftsman and I'd say maybe quieter then the HF DC. Is it safe to say that all the things you tested indicate hearing protection should be wore for each?

[MilDoc]

Wow. Prolonged exposure to noise over 85dB can cause hearing damage. Short term can cause a Temporary Threshold Shift (TTS), ie, a temporary loss of hearing, which can become permanent if exposure is on a regular basis. And I've been neglecting my hearing protection. Enough of that...

[LCHIEN]

quote:Originally posted by MilDoc

Wow. Prolonged exposure to noise over 85dB can cause hearing damage. Short term can cause a Temporary Threshold Shift (TTS), ie, a temporary loss of hearing, which can become permanent if exposure is on a regular basis. And I've been neglecting my hearing protection. Enough of that...

OSHA says you can stand 95 dB for 4 hours per day...
http://hyperphysics.phy-astr.gsu.edu...d/deaf.html#c5
but i wouldn't want to.

Short term exposure to high levels (e.g. rock concert at 100-110 dB)
http://hyperphysics.phy-astr.gsu.edu...ound/deaf.html
cause TTS as you said.

[LCHIEN]

I believe I made 2 mistakes. One as Zich pointed out the human ear apparently hears +10dB as an apparent doubling of sound level.

The second is I've used C-weighting which counts 32-10,000 Hz equally,
Perhaps I should have used "A-weighting" which mimics the human ear lower sensitivity to low frequencies at moderate levels by only rolling off below 500 Hz - I think this will make the DC look better on the tests which may account for some of the surprise being expressed.

So I'll take some more data later using the different weighting.
I also found out how to make peak measurements over a time period so I
can see how mcuh noise increases when actually cutting (before I was afraid to watch the meter while feeding... safety issue I always watch the blade and hands when feeding).
Reading the manual always helps with things like digital sound meters.

[vaking]

Loring,
The way I understand this math:
If a DC alone generates 90db and BT3000 alone generates the same, by turning them together I will have 93db (doubling the sound pressure) and a perceived noise level going up about 30%.
Is this correct?

[Kristofor]

quote:Originally posted by vaking

Loring,
The way I understand this math:
If a DC alone generates 90db and BT3000 alone generates the same, by turning them together I will have 93db (doubling the sound pressure) and a perceived noise level going up about 30%.
Is this correct?

Depends on how they interfere... If you were really lucky they could exactly cancel each other out (what your active noise canceling headphones try to do). I wouldn't hold my breath for that to happen in my shop though.

Kristofor.

[germdoc]

quote:Originally posted by LCHIEN

Short term exposure to high levels (e.g. rock concert at 100-110 dB)
http://hyperphysics.phy-astr.gsu.edu...ound/deaf.html
cause TTS as you said.

After sitting front row at a Clash concert ~1980 my ears were ringing for 3 days. You call it TTS--I call it NTS (Not Too Smart)!

[RodKirby]

Loring - please add a Router to the list...

[Tom Miller]

quote:Originally posted by germdoc

After sitting front row at a Clash concert ~1980 my ears were ringing for 3 days.

Did you stay or did you go?




Apologies,
Tom

[bigfoot15]

Rod,
The Triton that you and I are both proud owners of seems to me to be quieter than my Ryobi 1-1/2 HP and my Mastercraft (CDN Tire Brand, made by Dewalt I believe).
A thing of beauty it is.
I am still curious though

[LCHIEN]

quote:Originally posted by vaking

Loring,
The way I understand this math:
If a DC alone generates 90db and BT3000 alone generates the same, by turning them together I will have 93db (doubling the sound pressure) and a perceived noise level going up about 30%.
Is this correct?

According to the web site I used earlier (linked in one of my posts) the addition of two sound sources playing the same tones will apparently go up by 3dB to the ear which is a small increase.
You need 10 sources playing the same thing at the same volume to make the sound appear double in intensity.

However, the ear distinguishes between different sounds. Two sources playing different tones will not add in the same way - even small differences in tone will make it sound twice as loud. The ear is amazingly discriminating in that sense.

See this article and the link for adding loudness near the end of the second panel.
http://hyperphysics.phy-astr.gsu.edu...d/loud.html#c1

[atgcpaul]

quote:Originally posted by RodKirby

Loring - please add a Router to the list...

Have you noticed that Norm only wears hearing protection when he's
routing?

[JSUPreston]

Jeff, I had the same problem, but it was at a Maynard Ferguson concert in '93. I thought I was hot stuff--dead center seat on first row in front of the stage. Concert was great, and he was LOUD! The entire band was miked, and nobody needed any amplification, but it was cranked.

Since my 6 year old has started hanging out in the shop with me, I try much harder to use my safety equipment. I still need to buy an all in one face shield with hearing protection. I prefer the shield to goggles.

atgcpul, I could swear that I've seen Norm put much more emphasis on hearing protection lately. Seems like whenever I've tuned in, he's wearing it more often.