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Sound Deadening Install of '16 Wakesetter 22 VLX


Slurpee

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On 3/25/2017 at 6:06 PM, JeffC said:

I am just geeking out on this... What are you measuring/collecting all this data from?  I have a sound meter, but NOTHING that would support this level of data.   Where are you measuring from - is there a large variance from one position in the cockpit to another, or is it relatively consistent?

I'm using the RTA function of Room Equalization Wizard along with a calibrated MiniDSP UMIK-1 microphones from Cross Spectrum Labs.  I'm running REW on my Macbook Pro.  Feel free to duplicate my work.  It's a cornerstone of good research and I'd like to see how well the test method stays consistent between boats and the like.

If you just like the topic, then let me reccomend you go lurk on DIYMobileAudio.com.  Those folks are hard core.  It's kind of like lurking on AWSForums.com, but a more practical type of obsession for us boaters.  At AWS those folks are purists. 

Yes there is a difference depending on where you are sitting in the boat.  It's what you'd expect though.  All of these measurements were taken while using a mic stand on the floor next to the driver.  I'm not planning on posting the plots from when I was running down the lake, but I have those from two positions.  On the floor again and from a secured position on the dash with a foam decoupling mat.  What I observed was that the difference was about 3-5dB (louder the higher you go).  Just using my own ears it's pretty obvious to me that what you get is a lot more sound from wind and spray as you get above the sides of the boat.

15 hours ago, Lees23 said:

Interesting that the 17's are quieter than the 16's.  What has changed?

I know of absolutely nothing in the drivetrain side of things that has changed.  I suppose it's possible there might be thicker upholstery, panels, etc.  Mass plays a big roll in deadening sound.  I'll look into that when I get my hands on a 2017.  I can't see production variation being a reason.  There's just too many different components moving.

Edited by Slurpee
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Okay, so I had some time to do the data for the 3000rpm plots.  This is the most important for most of us I think since it's really close to where we're using the boat most of the time.  I think these will be the last ones I post for a while.  Going on some business trips.

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3 hours ago, Slurpee said:

I'm using the RTA function of Room Equalization Wizard along with a calibrated MiniDSP UMIK-1 microphones from Cross Spectrum Labs.  I'm running REW on my Macbook Pro.  Feel free to duplicate my work.  It's a cornerstone of good research and I'd like to see how well the test method stays consistent between boats and the like.

If you just like the topic, then let me reccomend you go lurk on DIYMobileAudio.com.  Those folks are hard core.  It's kind of like lurking on AWSForums.com, but a more practical type of obsession for us boaters.  At AWS those folks are purists. 

Yes there is a difference depending on where you are sitting in the boat.  It's what you'd expect though.  All of these measurements were taken while using a mic stand on the floor next to the driver.  I'm not planning on posting the plots from when I was running down the lake, but I have those from two positions.  On the floor again and from a secured position on the dash with a foam decoupling mat.  What I observed was that the difference was about 3-5dB (louder the higher you go).  Just using my own ears it's pretty obvious to me that what you get is a lot more sound from wind and spray as you get above the sides of the boat.

I know of absolutely nothing in the drivetrain side of things that has changed.  I suppose it's possible there might be thicker upholstery, panels, etc.  Mass plays a big roll in deadening sound.  I'll look into that when I get my hands on a 2017.  I can't see production variation being a reason.  There's just too many different components moving.

Thanks, once I get my 17 and get it wrung out I may well try doing some testing.    First priority will be getting the boat sorted out (my first Malibu, first wakeboat), but this stuff fascinates me. 

I built a casual home theater in my basement (really a den with a projector and 5.1 surround), but it is FUN.   When my kids were in High School, I never had to worry (except about excessive food consumption) because they and their friends were in my basement every weekend.   I had a lot of fun getting it calibrated.     

Having said that, I did NOT do the stereo delete on the boat to build my own.   For the boat, I really wanted to focus on learning to surf, and maxing out my time on the water this year.   I think the Wetsounds will be good enough, although I did only put one set of speakers on the tower... whether that is enough to overcome the noise on the boat without your mods remains to be seen. 

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1 hour ago, JeffC said:

Having said that, I did NOT do the stereo delete on the boat to build my own.   For the boat, I really wanted to focus on learning to surf, and maxing out my time on the water this year.   I think the Wetsounds will be good enough, although I did only put one set of speakers on the tower... whether that is enough to overcome the noise on the boat without your mods remains to be seen. 

Oh don't worry.  From everything I read you can definitely overcome the ambient noise of the boat with the Wetsounds stereo.  Not even a worry.  I wanted a quieter boat for the non-music moments to just chat while under way.  Just don't damage your hearing. LOL.  And enjoy that boat!  

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@Slurpee thanks for reaching out on the other thread.  I was just trying to get some perspective on how different the 17's are from the 16's and how much a surfpipe helps noise.  I am coming from a MC and got so sick of trying to hear the stereo or carry a conversation over the exhaust noise.  

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Howdy @Lees23,  dude I understand.  These are loud boats.  My buddies have recent model years MC, Nautique, couple of Wakesetters, Centurion, and they're all loud.  I just think it can be improved with some new applied engineering.  Eventually hydrodynamics and bling is all going to sort of wash out and a real differentiating factor that will command value can be comfort in the boat when you don't want to crank the tunes.  Best part is that it can be measured pretty easily unlike more subjective things like wake quality.  [that was rhetorical please no one answer! lol].  I think you see something like this in 2017 with Malibu doing a tune on the sound system for the first time that appears to be high quality by all reports.  

Now the surf pipe I am a believer in for sure.  The Sunsetter VLX I had before started with straight exhaust.  I had it for a couple years and it had a certain volume.  Especially behind the boat, but inside it to.  It never really bothered me.  But I'm a compulsive upgrader.  Going to STE turn downs helped a decent bit.  I could take them or leave them again if I was in the same kind of boat.  Probably take them, but more because of the look I guess.  A year before I sold my boat I installed a Fresh Air Exhaust.  It was definitely much improved behind the boat.  I think that was the first time I could talk loudly while surfing and be heard by the driver instead of having to shout.  It was also noticeably quieter (read noticeable, not remarkable) in the boat especially at low speeds and idle - not that you really need it that way then.  I've read from the gearhead forum sites that exhaust noise is a specific tone and timbre.  Squashing it changes part of what your ears are dealing with only. I wrote down what I learned about that a few posts up.

But back to the surf pipe.  It was money well spent.  I'm sold on them.  Like I mention in my first post, bringing down the noise of the boat is a fraction-here-fraction-there affair.  Make sure you're running one of the larger pitch props like 16.25" pitch or so.  That's the single biggest improvement you can make.  I can't however say how much a surfpipe improves the sound on a 16 or 17 compared to one without.  I've only had a 16 with it from the beginning.  Some folks are beginning to get their second boats two years in a row.  Hopefully a few are getting surf pipes for the first time and can give some opinions.

When do you get your new '17?

Edited by Slurpee
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2 minutes ago, Slurpee said:

Howdy @Lees23,  dude I understand.  These are loud boats.  My buddies have recent model years MC, Nautique, couple of Wakesetters, Centurion, and they're all loud.  I just think it can be improved with some new applied engineering.  Eventually hydrodynamics and bling is all going to sort of wash out and a real differentiating factor that will command value can be comfort in the boat when you don't want to crank the tunes.  Best part is that it can be measured pretty easily unlike more subjective things like wake quality.  [that was rhetorical please no one answer! lol].  I think you see something like this in 2017 with Malibu doing a tune on the sound system for the first time that appears to be high quality by all reports.  

Now the surf pipe I am a believer in for sure.  The Sunsetter VLX I had before started with straight exhaust.  I had it for a couple years and it had a certain volume.  Especially behind the boat, but inside it to.  It never really bothered me.  But I'm a compulsive upgrader.  Going to STE turn downs helped a decent bit.  I could take them or leave them again if I was in the same kind of boat.  Probably take them, but more because of the look I guess.  A year before I sold my boat I installed a Fresh Air Exhaust.  It was definitely much improved behind the boat.  I think that was the first time I could talk loudly while surfing and be heard by the driver instead of having to shout.  It was also noticeably quieter (read noticeable, not remarkable) in the boat especially at low speeds and idle - not that you really need it that way then.  I've read from the gearhead forum sites that exhaust noise is a specific tone and timbre.  Squashing it changes part of what your ears are dealing with only. I wrote down what I learned about that a few posts up.

But back to the surf pipe.  It was money well spent.  I'm sold on them.  Like I mention in my first post, bringing down the noise of the boat is a fraction-here-fraction-there affair.  Make sure you're running one of the larger pitch props like 16.25" pitch or so.  That's the single biggest improvement you can make.  I can't however say how much it improves the sound from a 16 or 17.  I've only had a 16 with it from the beginning.  Some folks are beginning to get their second boats two years in a row.  Hopefully a few are getting surf pipes for the first time and can give some opinions.

When do you get your new '17?

You are talented man.. thanks for all the info.  I have a buddy that has a 16 Tige Z3 with the base raptor and no surfpipe. I am not sure if the same tranny is being used but I have noticed the whine at higher speeds... wakeboarding and cruising speeds.  It's not terrible but if there is an easy way to help limit it, I am all for it.  I can't say that I would go the the lengths of putting sound deadening material in all compartments but if you found one compartment that seems to help the "most", like the in the transmission access compartment, I would do it.  And obviously adding the surfpipe(which will be done before delivery). 

I am am excited to hear the new Wetsounds equipment.  In my MC(2014 x2 with the gen 1 surf system)I repowerd the in cabin 7.7" JL's, upgraded the towers to 8.8" and re powered and pulled the IB sub out and replaced it with a 10w6 in a sealed box.  It made an amazing difference with the boat off..  but fire up the motor and the frequency of the exhaust just killed the low end and hearing any decent sounding music behind the boat was virtually impossible.  

I will pick up my VLX 4/8 as long as the sale of my MC goes well this weekend.  

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That's a good idea actually just doing the tranny area with sound deadening.  It's easy enough to pull the panels and measure that to see what difference it makes.  I'll make some time to do that in the near future.  That's the easiest area to do.

I did a simiilar all JL speaker system upgrade of my Rockford Fosgate system recently.  Sounds great.  Now I'm playing with a DSP to see what that's all about.  Major learning curve, but I'm having fun figuring out how to use my ears for the first time to judge the benefits.  Hah.  Funny thing to say that.

I guess my wife has been right all along and I'm a lousy listener sometimes. :)

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Just now, Slurpee said:

That's a good idea actually just doing the tranny area with sound deadening.  It's easy enough to pull the panels and measure that to see what difference it makes.  I'll make some time to do that in the near future.  That's the easiest area to do.

I did a simiilar all JL speaker system upgrade of my Rockford Fosgate system recently.  Sounds great.  Now I'm playing with a DSP to see what that's all about.  Major learning curve, but I'm having fun figuring out how to use my ears for the first time to judge the benefits.  Hah.  Funny thing to say that.

I guess my wife has been right all along and I'm a lousy listener sometimes. :)

When I bought the boat I had to agree to no mods for a year.. "you are spending that much on a boat then you don't need to make any changes, it should be perfect".  I guess I'll have to do it while she is away. 

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Ha.. nice.

I was thinking about going to a 2401 prop to help keep the RPMs and noise down as we typically don't have large loads of ppl with us and I doubt I will ever use more than standard ballast plus PNP.  The last thing I want is a boat that is stuggles to get to speed though so I am pretty hesitant to do this.

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6 hours ago, Lees23 said:

Ha.. nice.

I was thinking about going to a 2401 prop to help keep the RPMs and noise down as we typically don't have large loads of ppl with us and I doubt I will ever use more than standard ballast plus PNP.  The last thing I want is a boat that is stuggles to get to speed though so I am pretty hesitant to do this.

@bbattiste247 is running a 2401 on his 23 LSV and seems to like it. Altitude will have something to do with it working g well for you as well  

I'm ruining an OJ 925A (15x16.25) and like it. Though I'm going to borrow a 2401 soon to see what I think. 

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9 hours ago, Lees23 said:

Ha.. nice.

I was thinking about going to a 2401 prop to help keep the RPMs and noise down as we typically don't have large loads of ppl with us and I doubt I will ever use more than standard ballast plus PNP.  The last thing I want is a boat that is stuggles to get to speed though so I am pretty hesitant to do this.

In order for the 2401 prop to work effectively, you need to keep the boat fairly level. I have noticed that the prop works much better when there is little bow rise, so I keep a lot of weight up front. 

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3 minutes ago, bbattiste247 said:

In order for the 2401 prop to work effectively, you need to keep the boat fairly level. I have noticed that the prop works much better when there is little bow rise, so I keep a lot of weight up front. 

Yeah.  You've said that before and it's had me thinking.  I'm going to try it anyways to see, but I'm suspecting that my 22VLX being shorter than your 23LSV is going to put a different (and less useful) angle of attack on the boat.  That is more natural bow rise.  It might take more weight up front for the same results.  Time and testing will tell when I get to it.  Thanks!

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1 hour ago, bbattiste247 said:

In order for the 2401 prop to work effectively, you need to keep the boat fairly level. I have noticed that the prop works much better when there is little bow rise, so I keep a lot of weight up front. 

I certainly down want to have to worry about having a bow sack in oreder to get to surfing speed.  I think I'll go with the 2277 and buy the 925A and a second prop and see which one I like better. 

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@Slurpee:  Excellent report, thanks for taking the time to document. 

Given your expertise in the area of sound suppression, I believe I have a question that most likely does not have the answer that appeals to me and you touched on it already:)  For my application, weight savings and weight reduction are the target which is improving the slalom wake.  One project being a carbon fiber engine box to reduce the fiberglass box weight (65#).  The construction technique is a few layers of carbon fiber sandwiched around a 1/2" foam core inner and less dense foam for the vinyl cover.  You can probably guess, there is now some additional mechanical noise transmission through the engine box cover, really only noticeable at ski / barefoot speeds and not that offensive.  There is also air intake noise as I have an open inlet slot at the back of the box that feeds cold air to the intake (separated from the bilge).  I was contemplating adding some sound deadening material, and only thinking of a thin layer similar to what is applied to a CC200 (looks like a 1/2" grey foam but I have not real details) if and only if the weight would be negligible (1-3 lb max.).  Your thoughts on the level of noise suppression that type of foam would offer and how much it would weigh (I can't seem to find any good data on that).  Thanks in advance for any insight. 

An example:  https://www.mcmaster.com/#54495t44/=16zgdb3

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1 hour ago, Woodski said:

@Slurpee:  Excellent report, thanks for taking the time to document. 

Given your expertise in the area of sound suppression, I believe I have a question that most likely does not have the answer that appeals to me and you touched on it already:)  For my application, weight savings and weight reduction are the target which is improving the slalom wake.  One project being a carbon fiber engine box to reduce the fiberglass box weight (65#).  The construction technique is a few layers of carbon fiber sandwiched around a 1/2" foam core inner and less dense foam for the vinyl cover.  You can probably guess, there is now some additional mechanical noise transmission through the engine box cover, really only noticeable at ski / barefoot speeds and not that offensive.  There is also air intake noise as I have an open inlet slot at the back of the box that feeds cold air to the intake (separated from the bilge).  I was contemplating adding some sound deadening material, and only thinking of a thin layer similar to what is applied to a CC200 (looks like a 1/2" grey foam but I have not real details) if and only if the weight would be negligible (1-3 lb max.).  Your thoughts on the level of noise suppression that type of foam would offer and how much it would weigh (I can't seem to find any good data on that).  Thanks in advance for any insight. 

An example:  https://www.mcmaster.com/#54495t44/=16zgdb3

Howdy @Woodski.  I don't think I'm an expert.  But you're right about it being hard to find objective data.  I can save you the time in research at least.  Dealing with sound is four things.  Since we can't make engines themselves quieter we're left with the other three. 

There's blocking the transmission of sound.  That's all about limp decoupled mass.  My project in this thread.  That isn't in your project parameters obviously at 1lb/sf.  

Then there's stopping vibrations in panels that the noise gets to.  That is CLD products, but they're about 10oz each and for an engine cover I bet you'd need 25 or so pieces at least to be effective on whatever might be there vibration wise.  That's out of your weight specs as well.  Do you have a suspicion about the hatch vibrating like a drum?  Or is the carbon fiber sandwich rigid enough that it's not a problem you think?

The last treatment is with sound absorption.  That's the foam products like you were looking at.  Specifically the best stuff is Melamine foam.  And with that it's all about thickness.  3/4" foam might do the trick.  If you can make 1.5" work that'd be even better.  The deal is that the thicker it is the more the curve in the image below shifts up vertically.  For instance if you wanted to have any effect on 300Hz stuff you'd want to find a way to get a good 3" thickness of foam in there.  The 1/2" foams I investigated really were for taking care of higher pitched noises like whistles of air over surfaces and sunroofs and stuff.  Architecturally they put very thick blocks of the stuff up on ceilings and walls as artistic pieces to treat rooms for echoes and background noise.

I read somewhere the very nicely put explanation that vinyl will protect folks in a room from sounds outside the room.  And foam will protect folks in a room from sounds in that room.

I have a sample of the foam from when I was pondering the project.  It weights next to nothing.  I'd estimate 10-11oz cu.ft. measuring the sample I have with calibers and a scale.  It's a little flexible.  Like a very rigid memory foam pillow core.  Don from SDS will send you a sample if you'd like to get hands on.  I thought about the foam, but I expected a decent amount of physical abuse in the engine area from me never quitting with the poking around.  The Melamine has a lot of great qualities, but robustness is not one of them.  And it's not cheap either since it's treated to be water proof.  You need that since it's open cell foam.  I think it'd physically work for an inboard hatch though pretty nicely.

As for noise from the engine I'm guessing you're running 2000-3000rpm most of the time?  That's a main rumble from the engine of 150-200Hz. Then you'll have all the higher frequency harmonics.  I think those are the most jarring to our ears myself.  The foam if you could get 1.5" or more in there all over would have an effect I'd think.  I couldn't begin to guess how much of an effect.  I'd suspect a change in timbre at least.

If you're up to spending the coin give it a try and let us know! I'd love to see how effective the treatment would be.  Or email Don at SDS.  He's pretty engaging and has a lot of experience.  Mention Bryan recommended him.  That might make him feel better about the endless questions I asked if it steers more folks his way.

hmf-abs-coef.png

Edited by Slurpee
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Strapped on the 2401 today. No data points but will say I'm around 4-6 mph faster at equal rpm depending on speed. No ballast and 3 souls on board - 25 mph cruise at 3300 rpm. Sound noticeably better. Less resonance at that 3500 rpm mark. Just overall smoother. Not as aggressive hole shot but plenty for me.  

Agree on getting the nose down for surfing and efficiency of this prop. I stuck a 260 lb buddy up there with the factory and PNP hard tanks and sacks all full. I think the perfect remedy is if I can sneak 250-300 lbs of lead up there. Wave was big and crazy long.

Happy and impressed. 

 

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Cool. I swung by the prop shop today but couldn't get a 2401 loaner. I'm getting really annoyed at how hard it is to demo an acme prop after how easy it is to demo an OJ prop. Any tips folks?

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@Slurpee:  Thanks for the feedback, much appreciated.  To answer the questions you posed:  It strikes me as purely mechanical engine noise, the engine box is very stiff and happens to have quite a bit of damping as the bottom or resting surface is carpet on carpet so a nice damper there and when you put your hand on it while running there does not seem to be any vibration.  Engine speed for my use is 3500 RPM +/- 300 or 4100 RPM for ski speed and barefoot speed so the frequency is probably above your comment.  2-3k RPM is simply a pass through on the way to ski / footing speeds.

It is interesting you comment on making the engines themselves quieter, the options we (might) have are exhaust systems and mounting.  These boats solid mount the engine to the chassis (hull) so there is a lot of noise transmission to the boom box (engine cover or compartment) whereas your typical automobile has engine mounts that went through a very comprehensive and thorough development process to reduce transmitted noise using isolation mounting components.  I got the chance to ride in the electric Nautique a few years back, a very interesting experience as the power unit made little to no noise, you heard the prop noise, gearbox noise and water against the hull noise.  An amazing difference to the typical ski boat noise level.

Again, thanks for your thoughts and expertise on the subject. 

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@Woodski, that would be cool to experience.  I'm envious.  I'm also terrified of Li+ vehicle batteries (wait till one of them big boys vents and goes exothermic/ignites in your faces before you argue with me).  That aside it's just engineering and it's the future.  No argument.  Major vehicle manufacturers spend a lot of time on the sound of their vehicles.  Squashing what's annoying for what they can budget on that model versus the sound they want.  It's as important to them as their name and logo and stock price.  What's fascinating to me is the electric vehicle market is intentionally adding sound to their vehicles.  Very specific market researched sounds.  Resonators on the cabin walls.  Speakers external to the cabin.  To some extent they need to do that for pedestrians to hear the sneaky things rolling up on them.  But inside the cabin they do it to appeal to our built in sense of "wow" based on sound.  Interestingly it's old tech they are borrowing from budget sport sedans that do it to make the passengers hear a better exhaust and engine note than is really being produced by whatever is really in the drive-train (uber-sneaky).  Heh, it's like aural beer goggles while sober.  Once I had this fascinating conversation with a very high-end RC truck manufacturer about how their "toys" needed to sound like the real thing to keep their credibility once they went electric.  The E-Drive motors were kind of demasculting they learned!  When they took that toy petroleum engine sound (which was definitely loud) and transformed it into a realistic reflection of an all-terrain truck there were cries of joy.  Go figure, but it's not surprising if you reflect on it.  We live in a world defined by sight and sound.

You make a great point though.  What could be done with isolated engine mounts?  Stiffening structures to boost the hull resonant frequency beyond what the propeller or exhaust is causing?  A little extra dampening materials in the engine boxes? Tuned exhaust.... Constrained dampeners integrated into fiberglass layup? Aerodynamic deflection from the hull and glass?

These boats seem to have a sufficient enough market to keep raising prices.  That is a bit of a bummer, but it's the facts.  That means that there is going to be a race on multiple fronts to justify cost increases.  In the electronics arena they're borrowing 5-7 year old now-off-the-shelf (and obsolete) technology and productising it for lower than automotive sales volumes.  Engines are a world I just don't know much about.  I'm an EE.  However, history has set up it's own law of increases that have shown a trend to LOUDER, BIGGER, more CLEVER ballasts/engines and hulls.  It's amazing and welcomed!  Crazy welcomed!  The marine specific stuff is really booming it seems with crossover hulls, surf enhancements, and an adoption of computer modeling on a very competent level.

However, a convergence is coming eventually where there isn't much more to be gained from standing on the shoulders of others.  To continue to drive profits the biggest marine manufacturers are going to crave cross-discipline engineering R&D results .  For instance, "here's a magnificent hydrodynamic hull.  Here's a perfect engine for the towboat world.  Here's where we found places to make them merge flawlessly (e.g. sound). Now we can make your MP3s be glorious."  It will help to further define a Tier 1, Tier 2, Tier 3 I'd think.  It's gotten a tiny it muddy lately where the lines are and why between brands.  I bet we see similar things for steering, maintenance, cloud accessibility (the internet kind, not meteorology), dynamic ballast management, and whatever else comes up.... (retracting wakesurf ping-pong tables anyone?).

Tomorrow is Monday and I have to put a 5 year old to bed.  Wish me luck.

End-of-line

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Just now, hethj7 said:

This I can relate to!

Amen.  Is it normal to be able to tell a 5 year old is going to be better than you in every way?  I'm 41 and he kicks my butt some days.

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would cabin sound be reduced by removing the silent rider muffler? Larry at FAE floated the theory that removing that muffler and going straight to FAE would reduce the cabin sound by eliminating the resonance created by the silent rider.

Would automobile type isolated engine mounts would actually work on a boat? Would engine vibration be carried to the prop?

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5 hours ago, Chia said:

would cabin sound be reduced by removing the silent rider muffler? Larry at FAE floated the theory that removing that muffler and going straight to FAE would reduce the cabin sound by eliminating the resonance created by the silent rider.

Would automobile type isolated engine mounts would actually work on a boat? Would engine vibration be carried to the prop?

I've been following that thread with interest about removing the mufflers. I won't be trying that till my boat is out of warranty though. 

I wouldn't care about engine vibration to the prop. It's engine vibration to the hull that is an interesting question. I have only speculation on how a fiberglass hull with air on one side and water on the other responds to vibration from engine mounts. I'm *guessing* it's not as big a contributing factor as water rushing against the hull though.

And I know how prop rotation creates pressure waves against the hull making it thrum. Nothing changes that but moving the prop further from the hull, or making the hull denser so it lowers the resonant frequency out of what the prop generates. Or stiffer so that it raises the resonant frequency above what the prop generates. I don't really think that particular noise is all that annoying though. 

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