decibel meter and a small experiment

allen levine

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Location
new york city burbs
Im looking for a volunteer, a member Im familiar with to do a small sound experiment.
Has to have a small shop detached from his/her home and live in a suburban area where there are neighbors close by.


I purchased an inexpensive decibel meter. I read the reviews online and they were ok, just ok as long as the sound is over 60db.
Thats aroung talking level, or radio playing so I was ok with that.

IM going to log a few of my noisy machines inside the shop, with and without wood running through them. Then open the overhead door, do same steps at threshold of shop, 20 feet from shop, then at curb in front of home.
Doing each test with machines running and running with wood through them.Since someone has to run wood through TS or planer, another person will be needed to operate meter outside. If youre single and have no friends, this wont work unless you have a very smart dog.

I will also keep the radio on to boost the sound a bit.

I played around today, just to get an idea, and the machine seems to work fine.
I played the radio, got a low 60s reading, then turned on the dust collector, reading topped out at 75, then the TS, up to around 85-, the turned on the planer also and hit 92, that was standing in a enclosed shop dead center of shop in middle of all machines.
I went outside, left all machines on, the decibel meter didnt pick up anything greater than 60, which felt right, because outside the door closed, I just heard a slight hum.
I understand there are different frequencies, but noise is noise, whatever frequency, and I only want to know if Im making too much of it.
Ill conduct my little experiment this weekend.

Ill send the meter to someone and pay for return shipment so I get my meter back!(im not looking for a new member or someone who never posts, yeah, I said that, dont be offended, I just prefer
someone who I think would be courteous enough to send it back to me.)
Must have a garage shop, detached garage would be better.
I just want to make sure my shop is average.
 
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Hey Allen i would happily be your man if you like and i would gladly pay shipping back if you ship it to me.

Just one thing though i just thought i have double layer drywall on my shop.

But i do have a jointer and planner.

Try it with the planner crunching some wood and with the router cutting a bit of wood.

Those two are noise emitters and cause most of the trouble because of their high frequency.

High frequency permiates structures far easier than the low ones.

Happy to work with you and do any experiments you like. But i will also completely understand if you want to compare to a building more like your own.
 
ok, good, forgot about the router........real noisemaker, will include that.
Im going to also use a piece of ash or oak to run through machines. Cant send ya that. Ill ship it out to you one day next week.
 
Cool i look forward to it. Just dont put a value on it when you ship it and make it a gift. That way we can get it back and forth without the Queen getting her cut or Uncle Sam his. :rofl:

I have been dying to try this out.

I will do a whole report Allen. Airconditioners included. :thumb:
 
its not a professional meter, but the kind people buy to see if their band is making too much noise or if their neighbors party is too loud.
I believe its good enough for me to get a grip on the sound.
 
Leaves me out. In college when I took Physics, the teacher did a decimal test on the 80+ students in the class. Started out high decimals and went low, Teacher asked for us to raise our hand when we could not hear anything. I was the 1st to raise my hand.
 
I used to do sound level measurements for the motorcycle industry. (Yeah, I know...LOUD!):D:eek:

Allen,
Mainly, your meter will just read the level of the noisiest tool. Try turning on all those tools you mentioned, then begin turning them off - one at a time - starting with the quieter ones and progressing upward. I think you'll find that the 92 dB(A) you mentioned will only decrease a very little when the planer is the only machine left running.

Also, sound levels decrease in orders of magnitude as the distance form the source increases. That 92 dB(A) next to the planer may well be only in the 65~70 range when you're 25 feet away.

Next time your neighbor mows his yard, or uses a leaf blower, stand in your front yard with you sound level meter. I expect you'll find his mower or blower is louder than your tools at the same distance.

BTW, I hate it when tool manufactures list their noise levels as "and only 82dB." There are two things wrong with that: 1. Sound is measured according to either the "A" scale or the "C" scale. They differ a lot, but the "A" scale most closely approximates the human ear's perception. So, which scale are the manufacturers using? dunno... and 2. Sound level readings are oly usable when they tell you at what distance from the source they were taken. 82 dB means nothing, but 82 dB(A) @ 0.5 meter tells you pretty much everything you need to know.

For example the manufacturer of my dust collector advertises it as "under 65 dB." In actuality, it measured 85 dB(A) at 0.5 meters, and I had to get about 7 meters away to get their stated 65 dB(A).

One generalized rule of thumb: For each 3 dB(A) increase in sound level, the human ear perceives it as a doubling of the noise.

Sitting here in my relatively quiet home office, the background sound level is about 45 dB(A) at my desktop. Oops! Wife just came in. Sound level is now 75 dB(A)! :rofl:
 
understood, Jim, but I never have more than one machine on with dust collector at a time, so I wanted to keep it real. Just that machine with me using it and the dust collector. Whether the planer is louder or quieter than another machine wont make a difference since Ill be measuring each one by itself as I use them in real time.

I also noticed that the sound is different when I walk 10 or 15 feet to the right or left sound, the way it projects out of the garage.

Honestly, I do not think the machines turned on and me working on one with the door closed now is noticable up to my neighbors open window in the front room. Out at street distance, Im sure its just a faint buzz you have to listen for, not noticable if youre not straining to listen for it.
and jim, enjoy the doghouse tonight.
 
60 sounds pretty good. How loud is your house air conditioner? I'm pretty sure my shop is quieter than the AC is outside. I know the DC and grizzly planer are quieter than the AC, not sure about a router or miter saw.
 
I don't know about sound, I do know about light. I do not know of any reason why the drop off of the two would not be the same. That said:

The intensity of light falls of at the inverse square law. Everytime you double the distance the intensity is one-fourth. That is a bit of a tricky statement. If I could draw a picture you would understand it instantly.

Just take my word. If you measure light (and I am sure sound) intensity at one foot, when you measure it at two-feet, it will be only one-fourth as bright (loud).

This works when there is nothing but air between the source and the measuring device. Your garage walls, insulation, etc. will all reduce the sound even more.

I live in the city. From my shop wall to the nearest neighbor's outside wall is 32 feet. It is 47 feet from my house to the curb out front. Out back is absolutely no problem. I own 190 feet down the hill to a small stream. Then it is a couple city blocks beyond that, across and up the hill on the other side of the "valley" to the closest house. I say, "valley." To me it seems awful small to call a valley; however, it is a whale of a lot bigger than a gully.

All of that verbiage was to say that the only possible problem is one neighbor. The neighbors say that my shop sounds do not affect them at all, even when they have company out on the patio. (I try to do quiet things when they have company anyway.)

The closest thing to the neighbors is the dust collector, which is in an add-on, enclosed, not insulated, shed, with vents to the outside. This shed is outside of the shop. My noisiest machine is probably the De Walt 735 thickness planer. Routers are probably the next in the noisy line, then I would guess the jointer or TS. But the only two machines that operate at one time are the DC and another tool.

My garage doors are almost always about 1/2 way open.

The power tools across the street from me, do not bother us (The motorcycle and the ski boat motors are a different story. However, we can live with it.). We are certainly not going to complain.

I know this wandered. However, I hope it helped.

The clarity of my hearing has dropped off quite noticeably. Since this has happened I have become quite annoyed by loud sounds. A baby crying/screaming is quite painful to me for example. I am VERY much more upset by loud noise than I was. The power saw across the street, with his and my garage doors open, is not a problem.

Enjoy,

Jim
 
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Im not an expert when it comes to anything, other than aquiring or contracting illnesses.

sound, this is my take on it all.

Someone sitting 20 feet from a dust collector or large air conditioner, arent as likely to be bothered by the steady swishing sound as they would be by some "offensive" sound like a 735 planer fighting with some ash.
When a sound is piercing, noticable, its a bit unpleasant to people.
If you go into a broadway show, the music and singing can get quite loud, but its not offensive, its just loud.

Thats how I feel about my machines. some are offensive sound, some are just loud sounds. the low pitched machines are mostly non offensive.
The loud pitched screaming of routers and planers are offensive.

Offensive sound constantly can get to you.

My reason for soundproofing is only to stop the offensive sound.
If I ran only dustcollectors or mortisers, I would have never worried about the sound.
 
I don't know about sound, I do know about light. I do not know of any reason why the drop off of the two would not be the same. That said:

The intensity of light falls of at the inverse square law. Everytime you double the distance the intensity is one-fourth....Jim

Sound pressure levels (decibels) will decrease by about six dB when the distance from the source doubles. For acoustic engineers, this is referred to as the 'rule of sixes.'

Also, sound levels from multiple sources are not additive. The total reading will be very slightly higher than the highest single reading. In allen's case that means that, once he's feeding wood through the planer (90+ dB(A) at the source), the other (lesser) sounds from his dust collector, etc, are pretty much inconsequential.
 
results from sound test

Ok, 1.5 car garage, 320 sq feet, one entrance door, one overhead door, one small window.
Framed on a slab. Sound insulated on 3.5 walls and some fibreglass insulation tacked on inside of overhead door. Insulation on walls covered with 1/2 inch sheetrock.

Meter is not a professional meter:Schosche SPL1000F 135 db max.
Any sounds under 60 db doesnt really read on this meter, and 60 is about the level of normal conversation.

I held the meter right next to the AC inthe window while it was on, 69 dbs.

TS-sawstop 1.75hp cabinet saw-All readings were taken in front of overhead door. All readings included the DC running.

TS-door open, 74 dbs, door closed 61 dbs
TS-ripping 3/4 maple, door open 87 dbs, closed 65 dbs

Planer(dewalt 735)

Planer-door open 87 dbs, door closed 64 dbs
Planer- with maple running through, door open 89 dbs, door closed 68 dbs

Router(milaukee 5625)

Router-door open 87 db, door closed 61 dbs
Router-rounding over maple, door open 88dbs, door closed 62 dbs

My wife said walking 15 feet away the sounds were too low for the meter to pick up.

I didnt bother taking any other readings.

My feelings on it all, if you want to harass your neighbor, whether its kids yelling, radios playing, or TS's humming, youre going to harass your neighbor.

I will eventually put some tiles on the ceiling and build a folding screen made of out stiff insulation just to block the inside of the entrance door. Even if it knocks off a few decibals, the cost will be worth it. I want to woodwork in peace, not disturb anyone including my own family.
 
Cool i look forward to it. Just dont put a value on it when you ship it and make it a gift. That way we can get it back and forth without the Queen getting her cut or Uncle Sam his. :rofl:

I have been dying to try this out.

I will do a whole report Allen. Airconditioners included. :thumb:

Rob, FYI you might be able to find a pretty good SPL meter app for your Atrix. I have one for my iPhone that compares pretty closely with the Radio Shack meter I've had for years. (Bought it back then to balance my first surround sound system.)
 
and for what its worth, a reference? once a week I take a shower, whether I need one or not, and holding the meter at the shower door, the shower/running water in my enclosed shower was approx 80 dbs.
I know thats loud, but I cannot hear my wife talk to me when Im in the shower.
(sometimes I just yell to her cant hear ya, Im in the shower)
 
Wow, once a week? What are you, some kind of neat freak or something? :rolleyes: :p

I only shower in April...you know..."April showers bring May flowers" and all that. The rest of the year? Hello Old Spice! :wave: :D
 
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