Sound at SASC Events

[Wayne Dyck]

Here are the sound logs for anyone who is curious....

https://drive.google.com/drive/folders/0B90EOLfq2VvgbVpVUkZZbk02MXM?usp=sharing

Far too many comments / complaints about sound yesterday at YYC.

The SASC number one challenge maintaining venues is sound complaints. Over the years Westerner NE lot, Grey Eagle, and Fort Macleod have been lost, or close to lost, all a result of sound complaints. So in 2016, as part of our campaign to secure Fort Macleod airport, the SASC implemented the current 93 dB sound limit.

Why 93 dB when SCCA events are 100 dB?
#1  We are not in the USA running on old military sites, where allowances for high sound limits are tolerated. Many regional and local SCCA events are faced with the same pressure on sound limits as we are, and have implemented lower sound limits to maintain venues.
#2  City of Calgary... Bylaws Related to Noise
"In Calgary, all residents have the right to not be disturbed by noise. Sound is restricted to certain levels during the daytime and at night.
Traffic or vehicle noise
A person shall not create or cause any loud and unnecessary noise from a vehicle or any part of a vehicle.
A motor vehicle must have an exhaust muffler that expels the exhaust gases without excessive noise.
A person shall not drive or operate a motor vehicle if the exhaust outlet has been widened.
A person shall not drive or operate a motor vehicle if a device is attached to the exhaust system or the muffler that increases the noise.
Any vehicle in motion emitting noise measured at 96 decibels or more by a sound pressure level meter is “objectionable noise” and is in contravention of the Traffic Bylaw.
At Council on  July 5, 2011 the Municipal Traffic Bylaw 26M96 was amended by Bylaw 41M2011 and the following point was added to the definition of “objectionable noise”:
Noise measured at 96 decibels (dBA) or more as measured by a sound pressure level meter at any point of reception. Where “Point of reception” means any location where sound levels are measured with a sound pressure level meter."
#3  Municipal District of Rocky View No. 44
"Section 14. No person who owns, operates or controls a vehicle shall allow the engine of the vehicle to be raced or otherwise operated so as to cause excessive and unnecessary Noise."
#4  How do we measure sound waves?
Sound energy travels in waves and is measured in frequency and amplitude.
The energy in a sound wave can be measured using Decibels.
Amplitude measures how forceful the wave is. It is measured in decibels or dBA of sound pressure. Normal speaking voices are around 65 dBA. A rock concert can be about 120 dBA.
Sounds that are 85 dBA or above can permanently damage your ears. The more sound pressure a sound has, the less time it takes to cause damage. For example, a sound at 85 dBA may take as long at 8 hours to cause permanent damage, while a sound at 100 dBA can start damaging hair cells after only 30 minutes of listening.
#5  We enjoy the use of venues at the pleasure of the owners. But they have no real stomach to deal with noise complaints from neighbours. Venue owners typical response is to tell us to leave. End of Story.

Some of you may feel noise goes hand in hand with performance. Nothing could be further from the truth. A quick look at the sound logs from yesterday show...
Top 10 PAX finishers; 8 of 10 entrants consistently were less than 89 dB.
Top 10 RAW finishers; 7 of 10 entrants consistently were less than 89 dB.

The SASC places the Sound Meter 50' from the course, set to "slow" response. The microphone will be 3 to 4 feet above ground, perpendicular to vehicle traffic, at a point where the vehicle can reasonably be expected to be under load at full throttle.

Sound Variance... "my vehicle has been to many events and never been over". Each course has it's own points of "full throttle under load". It's not exacting. But vehicle sound, under a given condition, throttle position and load is. And the sound meter measures this accurately.
Examples: (this is not to point fingers, but to show variance between drivers in the same vehicle)
#92    84 - 85 dB
#192  87 - 88 dB
Entrant #192 was the more aggressive, experienced driver ~6% quicker overall.
#52    90 - 92 dB
#529  92 - 94 dB
Entrant #529 was the more aggressive, experienced driver ~4% quicker overall.
#51    84 -89 dB
#151  82 - 85 dB
Entrant #51 was the more aggressive, experienced driver ~5% quicker overall.

I think you get the my point. A vehicle's sound can vary noticeably based on more aggressive driving. Whether that be your own driving, course dependent, or with someone else co-driving.

Also, entrants that bring vehicles knowing they can not or will not meet the sound limit must not be encouraged or tolerated. All that happens is the SASC will jeopardize the continued use of the venue.

The SASC must be diligent in the enforcement of Sound. Failure to do so does not bode well for Motorsports in general.

[MurrayPeterson]

I have to stick in my opinion here -- every car that got a warning or worse on Sunday was *LOUD* from my position in the timing vehicle.  When I see the starter plugging his ears, I can only think that this is a problem.  The sound levels were right on track with other events (76-78 dB in my Miata), so I don't believe that accuracy was a big problem here.

Perhaps it is my advanced age ( ), but I have less and less patience with people that feel a loud exhaust is a fast one or even one that sounds good.  It isn't pleasant to others, and doesn't make you fast in this sport.

[BrianHemming]

Why 93 dB when SCCA events are 100 dB?

The "official" SCCA sound limit is 100 db, but almost all the locations they run at have much lower limits.  Even Packwood has a lower limit (96 db?) and it's about as remote as you can get.

[Wayne Dyck]

Have you ever been to Crows Landing...

Packwood is down right urban.

[SKI-R]

Hear, hear!   

Have to admit I was concerned about the awful note from the SVT.  I grabbed an app for my phone, did a weigh scale first gear max acceleration with it registering 91.4 dB......was recorded at ~85 dB at YYC, so you can check on your own.  As a marshall, there were a few that were a complete auditory assault, personally I appreciate your efforts to police this aspect.

[Canuck]

I was one of the marshals running the meter - I was almost apologetic for brushing off the driver that came by to complain while we were manning the meter (please don't do this).  We're competitors as well, and it's not to most complex thing to understand.  You know you're loud - we're not the "sound police" or there to ruin the event.  I really appreciate Wayne's clarification and the others for chiming in - it's not the sound meter or the marshal's fault that your car is loud.

The monitoring was more than fair - come on...a tip pointed away from the meter is spoofing the meter, bot reducing sound pressure! 

[ZiG]

Oh is that why the GT3 had them pointed off to the side? Yikes. I feel like a turndown is legit, but that.... No.

Heh, maybe the club should rent these out: https://m.summitracing.com/parts/dtc-772-32520

[Midnightsky]

I was one of the marshals running the meter - I was almost apologetic for brushing off the driver that came by to complain while we were manning the meter (please don't do this).  We're competitors as well, and it's not to most complex thing to understand.  You know you're loud - we're not the "sound police" or there to ruin the event.  I really appreciate Wayne's clarification and the others for chiming in - it's not the sound meter or the marshal's fault that your car is loud.

The monitoring was more than fair - come on...a tip pointed away from the meter is spoofing the meter, bot reducing sound pressure!

Disrupting the sound log station like that, just to complain, is complete garbage.   Such disruptions should be grounds for DNF to all their times.  If you have a complaint take it to the event organizers during a drivers meeting or afterwards privately.  As many have already said, its not the clubs responsibility to make your car quiet.  That's on the owner of the vehicle to be respectful and greatful that they even have the opportunity to run their vehicle locally on an autocross course.  We cannot be risking losing venues over a couple of clowns who want to run loud cars somewhere that it just isn't feasible.  Said individuals need to man up, accept their responsibility as a fellow competitor, and goto an exhaust shop to have something modified to lower the decibel level.

[Reijo]

It appears that we need a bit more education on sound here.  It is not quite as simple as we may think.

In that light, let's add some more facts to the picture to make our understanding of the situation more clear. 

Some new insights/thoughts/explanations have occurred to me for what we experienced Sunday.  I have been pondering this and I think there are some logical explanations and potential solutions for us:

1.  Background:  For a little over 2.5 years when I lived in LA I ran every event I could at San Diego and my S2000 always logged within 0.5 db of a typical value of approximately 92.6 db - almost without fail.  The case was the same at various Pros and Tours and Nationals with this car - very little variation even with the ambient air conditions (temperature, moisture content of air, elevation etc. which can all make a difference to the sound pressure waves generated (ever notice in winter how sound is more crisp/sharp?).  Nevertheless there was surprising consistency.  I don't recall there ever being a reading outside of 1 db of 92.6 either way (and we are talking over 10 years of running now ... That is a lot of events I can assure you).  Right now in our club we don't have that kind of consistency - not even close.  Why?  (p.s. this might explain some of the complaints from this past Sunday don't you think?).  I'll get back to this later.

2.  Car 529 was louder than 52 as Wayne mentioned.  I was driving car 529 and rode along with car 52 for most of the runs and am very aware of what happened for that reason.  My 2nd run was the most aggressive launch and it was my 2nd lowest sound reading!  The back tires spun and the back end drifted out that run on the initial left turn where the sound meter was located because the supercharger was putting out a bunch of power since I floored it that run ... and did not back off.  It was a bit too much throttle.  The run was my slowest.  That should have been my loudest recording for sound - the most throttle, right?  All other runs I held back to reduce wheel spin and I short-shifted into 2nd to prevent wheelspin.  That 2nd run of the day was the only significant tail wag at the start.  In fact, I would say car 52 was more aggressive than me on the launch than I was and held 1st gear longer than me typically.  By this criteria, he should have been louder, right?  And, in fact, on my last run I purposely held the throttle back slightly more with no wheelspin and short-shifted slightly more and that yielded my highest sound reading!  Huh?  I was wondering what the heck was going on by then as you might imagine (and prior to that ... as a matter of fact and why Tom and I looked into what was going on - as well as a number of people approached me about why the sound readings seemed to be out of wack.).  The loudest I heard for 529 was 94.6 db (might have been an error in radioing?  It is not recorded in any case and might have been an error.  Note that this was a car that has not been changed and has not registered above 89 db. at our previous events.  The exhaust is a Toyota TRD exhaust that has to meet 92 db roadworthy requirements from the government.  It is not a loud exhaust and definitely quieter than my S2000).  Why would we think something was amiss?  Anyway, I will come back to this later.

3.  Car 42 was louder than car 142 according to the logs even though I would estimate 142 was probably one of the most aggressive drivers out there on Sunday (yes, I watched him as many others do ... and I often do watch).  Therefore, more aggressive/faster does not necessarily equal louder.  Although, yes, in certain cases this can be true and I understand that over the course as a whole the car would likely be louder.  However, we talking about one specific location for the sound meter here.  The location is important and I"ll come back to this in a bit.

4.  Tom G. and I checked the sound meter placement (50' from where we could reasonably expect to have cars traveling - there were tire tracks/lack of marbles and dust) and it was more or less right ... I think we moved it 1 ft. - not really a big difference either way.  I'd say the original placement had been just fine. We also corrected the height (should be between 3' and 4' in height - it had been too low which can increase the reflected waves from the pavement).

5.  We observed about 20 or so cars pass by the meter and the readings seemed to be all over the place.  We readily agreed that some cars were noticeably louder than others and yet registered a lower sound reading and vice versa.  We did not disagree on a single car notably as to which one was louder and which was not.  Not one disagreement!  By that time we figured something was definitely amiss somewhere (and this is not a criticism of the operators by the way!  Not in the least!  We just knew we had a problem).

6.  Earlier we had checked to make sure the sound recorder was on slow-speed and NOT fast speed since this kind of variance could be caused by a simple error - not touching one button but that setting was correct when we checked on it).  Note that if the instrument is turned off, it goes by default to the instanteous (quick) reading mode.  We need to specify the slow or averaged meter readings.  It is like peak G's in a corner vs. sustained G's.  You want to deal with sustained G's not peaks which may be caused by bumps in the pavement or even jerky inputs on the steering wheel etc.). 

7.  The sound readings we saw while observing simply did not make sense.  Was the meter out of wack? We plan to look into getting it calibrated - which should be done as a part of maintenance.  More on that later.

8.  Earlier on in the day, apparently some of the loudest readings came from when the cars were well past the meter and that was what was being recorded (and beyond 50' ... note that sound diminishes at an inverse square rate - 1/(square of the distance)).  This would have been when the exhaust was pointing toward the meter (e.g. just before entering the first slalom).  That is why we put the box and cone (to hold it down) on the west side of the meter to minimize that effect.  We were supposed to be measuring sound perpendicular to the path of the car at 50' and not when the exhaust was pointing at the meter (it is the standard).  By the way, Murray, the exhaust would have been pointing at you in the timing car when the cars went by the first left corner at the light.  I would suggest a different angle for the placement of the timing car in the future or even place the car further away so you aren't being subjected to extra noise.

9.  Someone suggested taking readings only between the first two pointers (not beyond) and that seemed to help smooth out some of the readings once we instituted that measure.

10.  Wind:  Wind can carry sound pressure waves.  The wind was changing direction and increased as the day went on.  I thought that might be an issue but as Tom and I observed the readings that did not seem to have much influence on the results since the wind was somewhat gusty but not really strong although it did increase a bit later on.  I think we agreed on that.

11.  Notes on wind from Ft. Macleod (I manned the sound station a couple of times last time down there):  We know from experience there that if the wind is steady and strong from the west (Crow's Nest Pass), that we can easily hear cars at the extreme west end of the track.  If the wind is from the east, then the cars are hardly past the grid area when you no longer hear them.  Wind carries the sound - pretty sure we can all agree on that.  Last event when I manned the sound station at FM, I had to shield the mic from the wind to get any kind of proper readings because the ambient sound of the wind was approaching 85-90 db with the gusts of wind!  As the wind got stronger, even the clipboard held next to the meter did not help and I gave up trying to monitor the sound.  In fact, when the wind is like that, I doubt the neighbouring houses/people can hear any of our exhaust or tire noise.  There was no point to monitor the sound for the rest of the day.

11.  Notes on wind:  At the previous to last YYC event we, all of a sudden, started to get high sound readings (yep, people came to me to "complain" that time too - right away.  But, you know what?  If they come to "ask", there is probably a good reason for it.  We should think of the "complaints" as questions and for those with a "complaint", re-word them as a question - my advice for everyone.  Anyway, they did have a legitimate "question" because the wind was carrying the sound to the meter and, of course, the readings were elevated).  The solution was obvious and easy that time:  Move the sound meter to another point on the track where the wind was at 90 degrees to the track.  The readings went back to normal.  Problem solved.  The moral of the story is that if people are "questioning" the readings, there just might be something to the "question".

12.  At the end Tom and I did not come to conclusion about why the sound readings seemed too high and all over the place.  A number of vehicles (one had done work to his car to quiet it down and now was reading higher than before the work.  I think he had a legitimate “question”, don’t you?).  Anyway, the best reason/idea we could come up with was that the instrument may have gone out of calibration.  I later also wondered if the batteries were weak and were causing erroneous readings.

13.  After pondering the situation over the last day or so, I think the fault may lie with me.  Yep, me.  I have to take responsibility for this situation!  It was me who placed the sound meter near the start where we could “reasonably expect” to be on full throttle (and workers safe etc).  It seemed like a good location at the time, but I think that location was incorrect.

The location of the meter was exactly where I was short-shifting into 2nd gear!  My co-driver was shifting into 2nd beyond the point where the readings were being taken just like I did on my 2nd and full throttle run out of the box!  So, let’s see:  With a supercharger and most cars , in fact, when you lift on the throttle (I was not power-shifting someone else’s car nor do I mine), you can get pops and burbles of the exhaust…..a sort of spike in noise you might say.  I also remember some others shifting at that same point where readings were being taken among the “loud” cars and torquey (red Mustang I remember specifically).

In other words, the location may not have been ideal.  People were not on the throttle as per sound regulations and those throttle lifts for shifting could have been causing elevated sound readings.

Therefore, the sound meter should have been further down the track (maybe SW corner?) where cars were well into 2nd gear and full and steady on the throttle.  I suspect that would have solved the “problem”.  Anyway, it is the best explanation I have for what seem to be strange readings and could account for the differences between cars and even drivers!

Sorry about being long-winded, but I felt that we should get the full picture here before we all get carried away.  No one wants to lose a venue.  But we also want to be fair and consistent with these sound measurements.  Live and learn, eh?

As for the calibration?  Well, we should look into that as well.  What are the recommended calibration parameters (how often should it be calibrated/hr. of operation?) etc.

So, as you can see, sound is not exactly straight-forward as we might think on the surface.
 
By the way, I think sound readings in San Diego are more consistent because the Qualcomm stadium lot is not as exposed to the wind nor is it as windy in SD in general as it is in Southern Alberta.  That is probably why they have more consistent sound readings.  Also, I don’t recall the sound meter ever being near the start anywhere at big events down south.  It is almost always located somewhere near the middle of the course ... and a 2nd gear area where you are on the throttle ... not near any shifting or slow speed areas that I can recall.
 
So, in the future, going forward, we (and me) have to ensure we put a bit more thought into the location of the sound meter.

Again, this was my mistake … I placed the meter there at the start.  My apologies for causing all this angst (the most ever over sound)!

Cheers,

Reijo

[SKI-R]

Well, sound limits are LIMITS....

Whether it's w.o.t. or liftoff and exhaust burble or B.O.V. release - the same limit applies.  Unless the meter calibration is off there's no need to apologize - you should be able to have sound meters everywhere on the course without anyone exceeding maximums.

[Wayne Dyck]

The points I was trying to make...

- Sound disturbance / annoyance is very arbitrary.
- Squealing of tires, back firing, pop off valve release, boom box, car alarms going off, all can be considered a disturbance and annoying.
- Provincially, municipally there is no set standard, although 96 dB is referenced at times.
- Sound measurement is not an exacting standard, but doesn't need to be.
- SASC has adopted a procedure somewhat taken from SCCA, but it is not the gospel.
- Attempting to measure sound only at one type of load point, wide open 2nd gear (example), may miss the real annoyance factor of back fire or pop off valve release.

John Q Public does not give one hoot about dB readings, so called standards, etc. If he finds it annoying, he complains. If he complains, he's heard, and we lose. End of story.

[Reijo]

Well, sound limits are LIMITS....

Whether it's w.o.t. or liftoff and exhaust burble or B.O.V. release - the same limit applies.  Unless the meter calibration is off there's no need to apologize - you should be able to have sound meters everywhere on the course without anyone exceeding maximums.

Well, if we put a sound meter right behind the exhaust pipe of all cars, I guarantee all cars will fail.....every single one, even with stock exhaust.

So unless you have some valid scientific reason, that is just nonsense.  Maybe we should think of the children too ... and the world is going to end etc.  That's the same kind of reasoning.  Nonsense.

R

[Reijo]

The points I was trying to make...

- Sound disturbance / annoyance is very arbitrary.
- Squealing of tires, back firing, pop off valve release, boom box, car alarms going off, all can be considered a disturbance and annoying.
- Provincially, municipally there is no set standard, although 96 dB is referenced at times.
- Sound measurement is not an exacting standard, but doesn't need to be.
- SASC has adopted a procedure somewhat taken from SCCA, but it is not the gospel.
- Attempting to measure sound only at one type of load point, wide open 2nd gear (example), may miss the real annoyance factor of back fire or pop off valve release.

John Q Public does not give one hoot about dB readings, so called standards, etc. If he finds it ann

oying, he complains. If he complains, he's heard, and we lose. End of story.

Yes, you're right.  Some people don't give a damn about others and complain just to be heard or something .... They are called nimbys.  Some of them you will never please.....unless you are gone altogether.

You should know this really well, Wayne ... just like those f'ing BC enviros paid by foreign interests don't want our oil flowing through BC no matter what we do.  There is no pleasing them, so why should we bother to try pleasing that bunch of fringe lunatics - complete waste of time and effort.  It sounds like a good idea ... just like the NDP government trying to please those idiots, but in reality it ain't gonna work.

So, we have to draw the line somewhere and do our best within reason. 

Something else, there were planes taking off the entire time and flying directly overhead every 15 sec. or so during the first part of the morning.  I looked at that as a possible cause of noise too ...  I remember a couple of planes without the hush jet technology and one drowned out the 3 cars on-course at the time.  The newer planes can be taking off under full throttle and they are quite quiet.  Then later on, the planes were taking off in the other direction and there was another that took off on the west runway and I could hear it clear down the runway to past McKnight Blvd and after it left the ground.

We aren't anywhere near as loud as those planes.  But anyway ...

I'd like to keep it quiet too but do we quit running every time the wind is blowing the wrong way?  We have to be reasonable.  There is also the discretion of the people running the event allowed for whether a car is too loud or not in the rules ...

There was some other observations I made as well, so what I'm saying is that if you really want to define sound and what is too loud, the definition is not so black and white and easy to determine.  Beyond that it becomes just a bunch of emotionalism and whatever other nonsense and I'm not interested in going there.  It is nonsense.

[Jackal]

Personally I feel we should keep this more on topic. Environmentalists, Extremists, the NDP, and "the children" have little to do with the event this weekend. In the end we can agree that some people can never be fully pleased... However those same people have potential to end events at YYC,  so reasonable limits through all conditions must be met to avoid that scenario.

I can only speak from the experience in my car as I have never run the sound station,  but had to have the warning conversations in the pits this weekend. 

My car traditionally has never blown over 73 dB at other events.  This event however I did average 73.4 dB with a high blow of 78.6 dB on the last run of the morning.  While most of my runs were exactly as expected,  there was one unexpectedly high result,  and a couple slightly higher than the norm.

I have been reading about the effects of heat on sound over the last day or so,  to see if that could have been a probable explanation for the slightly higher results and occasional very high result.  Although the velocity of propagation is higher in the heat and can cause greater refraction of sound off the ground; with it being as dry as it was on Sunday,  the two effects should have cancelled and at 50ft,  it should have been a very minor change. My theory also doesn't support the fact that from my own personal experience I experienced the occasional pop up in sound,  and the largest pop being before the full heat of the day set in.

Personally I think that the park and ride here is the best venue we have and will do my part to ensure we keep it.  I just thought I'd add in my personal experience and a theory I explored a little since then.  As an aside.... Sound propagation and it's relation to heat is some great bed time reading.   

 

[Reijo]

Good points, Duane.

Sound transmission is affected by a number of factors ... even the current barometric pressure ... something else that hasn't been mentioned.  It is, unfortunately, not an exact science.  I wish it was.  It would be so easy then!

When looking through the sound logs, I noticed the same uptick in sound levels on the 3rd and 4th runs in the afternoon.  It cannot be because people were learning the course and getting significantly faster (to a degree, yes) because we ran the same course in the morning.  Something had changed.

Something I forgot to mention directly was the effect of background noise from the wind.  That was why we had to stop recording in Fort Macleod the last time because the meter was reading over the limit when there were no cars around.  Yep, it was windy.

At YYC this past weekend the wind picked up in the afternoon (first thing in the morning, it was essentially calm).  The wind picked up late in the morning with varying gusts from varying directions (seemed circular almost) and continued to build as the day went on.  That may have affected the readings for sure.  Maybe that is part of the explanation for why cars were all of a sudden louder than the morning.  Furthermore there were wind gusts the entire time.....which could have caused "surges" in volume.

Anyway, I guess we have to be aware of these factors and maybe we have to weigh the results in or provide wind protection for the sound meter. 

A final thought:  Have you ever tried to do a video recording on a windy day?  How was the sound?

R