WTF decibel test? TORCH LAKE MI
 

So last year I was sound checked at 96 decibels on my own action pulling Sheriff Tim Tilly over. I just figured it was not worth the hassle getting pulled over so I figured I would get a baseline test and comply with the laws. I added some stainless insert type cones I picked up from summit racing and got rechecked a couple weeks later. I checked watching the meter bounce around from 90.8 to 93. Sheriff Tilly was happy and wrote me a sound check sheet at 90.8db and said I was borderline. In response I added Gibson mufflers and made sure to point them out to him for which I got the thumbs up from him. Never got checked with the mufflers and it was obviously much quieter.

Now this year comes around and there is a new Sheriff in town. I decide to get tested so as not be hassled at a later time. I pull the new Sheriff over again, have a not real pleasant conversation with him and get tested. Now I am at 103 decibels? WTF!!! I mentioned something about something has got to be wrong with his meter. He said they are all the same and you must have done something to your boat over the winter. I replied yes...I added the mufflers and there has to be a problem with his meter. Now I could see I wasnt getting anywhere with him. I pulled out my sound check sheet from last year and showed him...he didnt look like he tried to hard to read it and repeated that I did something to the boat.

He looked like he was about 4ft back and 4ft up. I did not see him calibrate his meter and I also did not see it bounce around like I did last year. Does he have the meter set to hold the max level? What the hell is this guy doing wrong?

He may not be doing anything wrong...
 

...just not right!

So I called a friend of mine who plays music. They meter where they play to make sure they are not over-blasting the neon haired patrons!

His statement was to the effect "usually if a meter is not reading correctly, it reads low, not high". He made it a point to say they are electronic, so anything is possible. It could always be the original test was faulty.

He also said if you set a sound level and move the meter a little there will be some change, but that change is minimal.

I just looked for a decibel meter on line and they vary from $40 to the sky, but there seemed to be a number of them in the $70-$100 range.

http://www.radioshack.com/product/in...uctId=12680845

Have you ever been pulled over at Torch? I have been going there for years and they don't even look at me twice. I sure hope they aren't cracking down there!

Where did they test you? Were there docks, bridges, etc around that could cause the noise waves to bounce off? Was his boat behind you? What was the ambient noise level? All these can affect the reading.

Yes, I was idling back to the sand bar half broken down and Tim Tilly (nice sheriff BTW) warned me that I was loud but didn't have his meter with him. That is when I decided to be proactive.

The lake association bought a meter for the Anterim Co. Sheriff. They are not on every boat and Kalkaska Sheriff does not have one.

Figures. I guess I'll wait and see what happens when I go up. I know I'm over but I don't have a lot of room to work with.

So, what about how he tested you? Boat position, docks, etc?

BTW you can get a db meter app on an Iphone. Probably not super accurate but can be used to test with and without mufflers to see the difference.

I bet my lunch that the new sherriff is using a different "weighting scale"
There are different db scales that relate to how humans can hear sound. A-weighting is most common, and what is usually used when measuring industrial sounds. If he had it on a different scale, or had the weighting turned off, you will get VERY different numbers. It would be important to read the statute, and understand what scale is expected by your governing body. If it does not say, I would collect evidence that OSHA uses A weighting and bring that to the new sherriff...make sure he takes the test again with the correct setting.

Yes, there are also max hold, and response functions on many db meters. If you set your meter to a slower response, it will not bounce around as much, and be more of an average...that would be in your favor, as it would not be showing the much higher spikes an engine can exhibit.

Get yourself a cheap radio-shack db meter...they work great.

Test was in the middle of the lake far away from anything. Ambient sound was like 68db...which seemed high to me. I also read in the law they award supposed to subtract 3db when testing from another boat to counter any reflected sound.

I have a high quality industrial decibel meter if you would like to borrow it
just pay shippiing both ways and I need to make sure I get it back

Kevin

Bingo,

I bet he has the weighting off. The radio shack meters are pretty good,,,, I have a I phone app but haven't tested how accurate it is.

Look up the law, I bet it will say A weighted, and if you are over 100 A weighted that is LOUD.

Read this... http://questtechnologies.com/Support/boatnoise.aspx

That article says 50ft...so what's the correct way to measure in Michigan?

Looks like its anyones guess... I did a search for "noise decibel meters that boat police use" - check out how many ordinances pop up!!! I would say that each city, or lake may have its own standards, but this company (if particular city/lake buys from them) is probably going to recommend their test standards. Bottom line is, its still in the hands of Barney Fiffe, and worse, Mayberry.

No, Michigan only does at idle.

Last I knew they could do either SAE-J2005(stationary) or SAE-1970(moving) but obviously stationary is much easier.

You are correct it is suppose to be measured at slow response and A weighting.

I have a radio shack DB meter. They are inexpensive and very good. 103 db is very loud. 90 db is not too tough to get to on a boat with mufflers. I once had a boat that was 572 CI blower with straight exhaust test at 105. That boat was really loud. When you would start it at the docks it would make people jump if they were not expecting it. I agree with the comments about what weighting scale he is using. Big differences. The radio shack meter will help a great deal. Most tests are 3' back and 3' up from the transom.

103 doesn't sound right. I got a ticket on Lake George, NY for 99.2 dbs on my single 525 EFI with straight pipes. A sunsation with the same motor registered 98 and my brother 29 fountain with the same motor was 97 dbs. This was done with a meter stick to the transom. A guy on the lake with twin 500 efis and CMI mufflers pulled 90.3.

I remember that one... The year prior I was a 92 FB straight pipes stock manifolds with 330's. Still haven't paid..

I very much appreciate the offer but I think I will buy the same meter he has or atleast the same brand. I did get a good look at it.

I agree, it does my sound right. I had a guy check me with a radio shack meter 3yrs ago and it was around 96 db with my stock package...575sci with e-tops and no mufflers. I just hate to piss in this guys wheates and say he is wrong as he does not seem to be the type that would ever admit to being wrong.

I put money on it that he had it on C-scale or unweighted. The C-scale will read much louder if there is a lot of low frequency sound, which V8 engines do.

I have a sound level meter which reads both A and C scales. I'll give it a try with my Trans Am with LT1 engine and see what happens. Also 68 ambient is VERY high. If you are on the lake with nothing else going on, it should be more like 35 to 45. In fact, if you start out at an ambient noise level of 50 or above, don't even bother running the test.

Michael

I usually don't post here, but I was told this was being discussed, and I have done a bunch of research on it with the current laws, (and th proposed changes they have been trying to push through).

Here is the Michigan law as posted. The shoreline, moving, law is the one that is almost impossible to beat. Even the outboard Sheriff's boat failed it when they ran the tests (in Higgins I believe, I'd have to check my records).

If you want, most know where to find me, but I'll try to check this thread once in awhile.

6.10 Equipment Requirements and Required Personal
Flotation Devices

A. Misdemeanor—Equipment Requirements

MCL 324.80156 details the sound requirements for motorboat mufflers and underwater exhaust systems. MCL 324.80156(1) states:
*MCL 324.80156(2) allows the DNR to establish rules for alternative sound level tests and maximum decibel levels.

“Subject to subsection (2),* a person shall not operate a motorboat on the waters of this state unless the motorboat is equipped and maintained with an effective muffler or underwater exhaust system that does not produce sound levels in excess of 90 dB(A) when subjected to a stationary sound level test as prescribed by SAE J2005 or a sound level in excess of 75 dB(A) when subjected to a shoreline sound level measurement procedure as described by SAE J1970. The operator of a motorboat shall present the motorboat for a sound level test as prescribed by SAE J2005 upon the request of a peace officer. If a motorboat is equipped with more than 1 motor or engine, the test shall be performed with all motors or engines operating. To determine whether a person is violating this subsection, a peace officer may measure sound levels pursuant to procedures prescribed in SAE J1970, issued 1991-92.” A person who violates MCL 324.80156(1) is guilty of a misdemeanor punishable by: • imprisonment for not more than 90 days; and • fine of not less than $100.00 or more than $500.00. MCL 324.80156(6). In addition, the person must install a muffler or underwater exhaust system that meets the act’s requirements before putting the vessel back in use. Id.


R 281.1238 Mufflers; cut outs.
The exhaust of all internal combustion engines used on any waters of this state shall be muffled effectively by equipment so constructed and used as to muffle the noise of the exhaust of the engine in a reasonable manner. The use of cut outs, bypasses, or similar devices is prohibited, except for vessels competing in a boat race or regatta sanctioned by the department under sections 151 and 152 of the act. A modern device, underwater exhaust system or a system discharging cold water through the exhaust of an inboard engine, each of which is capable of muffling the noise of the exhaust of the engine in a reasonable manner, shall be considered as meeting the requirements of this rule.

Yeah, when he said ambient was that high I thought something was up rite away. I really appreciate everyones input on this. I will definately have ammo now. I had no idea about the weighting scales.

Rat, I saw you posted on chickens thread in our regional section. This sucks because I'm a guy who is trying to be compliant and will be into this for over $1000 if I buy the meter.

J, copy and paste this, then laminate it and carry it on the boat to make sure they perform the test properly. IMO there's no reason to buy an expensive meter as it will be a moot point if Jonny Law says you're over.

Procedure 4.

4.1 Measurement Site—A suitable site is a body of water free of large obstructions or reflective surfaces such as
buildings, boats other than those involved in this procedure, large embankments or breakwaters, etc. for a
minimum distance of 8 m (25 ft) from the boat being measured. The boat being tested shall either be moored
to a dock or lashed to another boat. If moored to a dock, the dock shall be of open construction so that it
presents a minimum of reflecting surfaces. If the measurement is made in open water, the boat being
evaluated shall be lashed to the measurement boat to prevent relative motion and to allow positioning of the
microphone in the prescribed location. The measurement boat shall be positioned to minimize reflected
sound.

4.2 Boat Operation—The engine shall be operated at low idle speed within the engine manufacturer's
recommended operating range, in neutral gear if so equipped. For motorboats without a neutral gear, the
engine shall be operated at its lowest operational speed. The engine shall be operated for a sufficient amount
of time to allow water to flow through the exhaust system before taking measurements.

4.3 Measurements

4.3.1 The microphone shall be placed at a distance of 1.2 to 1.5 m (4 to 5 ft) above the water and no closer than
1 m (3.3 ft) from the vertical projection of any part of the boat in the area adjacent to the exhaust outlet(s).

4.3.2 The meter shall be set for slow response and the A-weighting network.

4.3.3 The observer reading the meter shall not be closer than arm's length from the microphone to minimize sound
reflections.

4.3.4 The applicable reading shall be the average sound level measured during a period when the background
sound level is at least 10 dB lower than the measured sound level. Background sound level includes wind
effects, noise from boats other than the one being measured, wave action, boat wakes, and other extraneous
noises. Peak readings of intermittent sound levels created by wave slaps or changes in sound level due to
wave action and/or engine speed variation shall not be included in the applicable reading.

4.3.5 The observer shall record the applicable reading and the background sound levels taken immediately before
and immediately after the applicable reading.

Am I reading this right...switchable mufflers and silent choice are prohibited?

There meter is messed up. Guy on another thread put up the EXACT same reading as jrider put up. 103.9.... Cops don't ever keep their breathalyzers calibrated so wtf would there decibel meters be any different.

The way some cops read it they say they are prohibited. The reality is silent choice is fine because you are going from one form of muffling to another. You would have to pass the test with the loudest form of exhaust equipped on your boat though.

Could not be too far off it a few things where taking place.

I was tested on the 4th on the St Criox and was very SURPRISED and happy what mine came in at.

But I will say several major things helped with a more then accurate reading then I ever have!!
First, he let the boat run several minutes BEFORE setting up the measurement
Second, he used the proper 'sticks' for measing where the meter is supposed to be at and not just held out at arms reach.
Third, his boat was on the SIDE of mine! So no bounce back of sound. Many years ago I was tested and the DS had his boat right behind me and I read over 110!!
Fourth, I made damn sure that the back of the boat was pointing as far away as possible from ANYTHING! Shore, other boats as well as other boat traffic. I chose the location and made sure we floated that way :)
Lastly, he was the more sincere pleasany officer I have ever dealt with on land or water!
I have stock twin 502's, y-pipe with straight out exhause as well. No diverters on the ypipe at all.
I have am also runnint Teague 4.5's switchable tips. The switch is/was closed during this test as its wired closed with the main power switch.
He came up behind us in the no wake area and was commenting on my sound level.
I told him my version of things :) and he still wanted to test :(
After everything he agrees with me that the fact of still have the open ypipe allows too much water to go our the prop exhaust then the tips, this increasing the sound level. He too was surprised that I read out at only 82! :)
My tips are also on top of my swim platform and is in high above water level :(

When the meter first started it peaked at 112, then 107, 105,101, 99, 96 and then settled on 82 :)

So thus my final thought is that if he did everything else properly, did he leave the meter running LONG enough to let it settle down? It really seemed like he had the meater there for well over 3 minutes and the wife said over 5 minutes he held it there!

Just my thoughts and personal experience!

Wecome back Paul!!!!

Tired of talking to himself

The MI testing method and what not was discussed pretty good in this thread. :(

http://www.offshoreonly.com/forums/g...i-exhaust.html

He can make a phone call if he needs someone to talk to. :violent-smiley-021:

AS an FYI i was sound checked at Higgins lake this past weekend and they let me go at 97 db but the next day was told they gave out 4 tix for excessive noise.

Saw this yesterday too...

http://www.petoskeynews.com/charlevo....html?mode=jqm

i think everyone with 5 inch dry exhaust should raft up in front of Bill Henne's house and bounce their engines off the rev limiters a few times

I want to call up the police and compliment the area for all the cool loud boats that are here. Tell them we come to this area just for that reason. It only takes one guy complaining to stop the cool boats that men women and children find so amazing. No reason calls shouldnt come in to compliment the loud boats

A Radio Shack dB meter!!?? Can you even calibrate that thing. I would question that immediately if pulled over.

I always wonder when they say have boaters use silent choice how we are suppose to do that and not damage the motors.

This year going dry exhaust...going to be loud!

From the news article:

"So the biggest thing we want to do is educate boaters," (Lt./Sheriff Dept.) Richards said. "Let them know if they are over or under the limit."

In some cases, he said, boaters may be requested to close their "flap exhaust," which is designed to reduce noise.



I can think of a couple people that need to close their exhaust flaps, namely Bill Henne and Nancy Ferguson.
If I drive by their homes and their faces annoy me, will the local constabulary make them put paper bags over their heads?