This page discusses converting, although I've never done it, just used a dBA test unit. There is one chart in the middle of the page that shows some frequency conversions.
Decibel A, B and C
How noisy is your boat?
- Thread starter Hawgwash
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
This page discusses converting, although I've never done it, just used a dBA test unit. There is one chart in the middle of the page that shows some frequency conversions.
Decibel A, B and C
Keysdisease
Guru
What you want is a "an insulation that incorporates a mass loaded vinyl noise barrier" as in a vinyl/foam composite insulation, see picture.
In many insulation installations on boats you see a silver or white mylar face with foam behind it. Foam is a noise absorber, but does little to stop the transmission of noise. Real noise insulation incorporates a mass layer between an absorption layer and a decoupler layer. 20 years ago the mass layer was lead, today it's mass loaded vinyl which works just as well.
Technically mass loaded vinyl alone would be effective incorporated into a cover on the outside because it was not directly exposed to the noise. On the inside a 1/2" overall thick vinyl / foam composite would be best.
In many insulation installations on boats you see a silver or white mylar face with foam behind it. Foam is a noise absorber, but does little to stop the transmission of noise. Real noise insulation incorporates a mass layer between an absorption layer and a decoupler layer. 20 years ago the mass layer was lead, today it's mass loaded vinyl which works just as well.
Technically mass loaded vinyl alone would be effective incorporated into a cover on the outside because it was not directly exposed to the noise. On the inside a 1/2" overall thick vinyl / foam composite would be best.
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dhays
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FWIW, today running at 1500 rpm we recorded about 70db in the Pilothouse, 75db in the saloon, and about 80db down in the companionway between the cabins and head.
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That's a very comfortable level, Dave! I'm not as lucky but I'm planning to improve the situation soon with Soundown carpet underlayment. My wallet just needs to recover after back-to-back battery and refrigerator replacements.
I downloaded the Sound Meter android app and measure the sound levels in the salon and at the lower helm today. They measured a consistent 78-79 dB at my cruise 1800 RPM. I didn't measure the FB or forward cabins.
I downloaded the Sound Meter android app and measure the sound levels in the salon and at the lower helm today. They measured a consistent 78-79 dB at my cruise 1800 RPM. I didn't measure the FB or forward cabins.
I just finished a 15 hour transatlantic flight on a new Boeing 777 and was wondering why it was so noisy. Then I remembered the handy little app on my phone so I took sound readings, which were very surprising:
* Noise level at front of plane (economy seating) 90 dbA
* Noise level towards rear of plane 95 dbA
* Peak levels about 100 dbA
The foam ear plugs quickly went back into my ears! I wonder how many pilots and cabin crew suffer from permanent hearing loss?
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Wow, I would not have thought it was that loud in a 777. I've been to the UK and back, (20 hours each way accumulatively), and I thought they were quite quiet. I have the same app, and in my car at 100kph, (your 60mph approx), it is 55dB in the driver's seat. I have yet to test the boat. Haven't been out in it since I dowloaded the app.
Edelweiss
Guru
20 hours Peter, that is just insane!
Was that nonstop to Heathrow?
Beats my 9 hour flight to London all to HECK, I can barely get off the 777, go through Passport control, screening and walk to the other end of the terminal for my connecting flight to Madrid. They must take you off on a gurney.
Thank God for Bose Noise Canceling headphones. A must have for long flights and screaming babies.
Was that nonstop to Heathrow? Beats my 9 hour flight to London all to HECK, I can barely get off the 777, go through Passport control, screening and walk to the other end of the terminal for my connecting flight to Madrid. They must take you off on a gurney.
Thank God for Bose Noise Canceling headphones. A must have for long flights and screaming babies.
BruceK
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Another vote for noise cancelling earphones on our recent long haul 777 and 787 flights. They work, but so do earplugs.
There are no nonstop commercial Sydney-UK(or Europe) flights. Qantas once flew London to Sydney with a lightly loaded specially fueled 747-400 as a stunt, but commercially it`s not on.
Aussies are used to long flights, with stopover, to Europe. West coast Canada and USA at 13-15 hours are easy.
There are no nonstop commercial Sydney-UK(or Europe) flights. Qantas once flew London to Sydney with a lightly loaded specially fueled 747-400 as a stunt, but commercially it`s not on.
Aussies are used to long flights, with stopover, to Europe. West coast Canada and USA at 13-15 hours are easy.
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20 hours Peter, that is just insane!
Beats my 9 hour flight to London all to HECK, I can barely get off the 777, go through Passport control, screening and walk to the other end of the terminal for my connecting flight to Madrid. They must take you off on a gurney.
Thank God for Bose Noise Canceling headphones. A must have for long flights and screaming babies.
That was 14 hrs Brisbane to Dubai, then 6 hours Dubai to Heathrow. 2 day stopover in Dubai on the way, to visit Ferrari world, and sus out the Yas Marina F1 circuit. Only a short 3 hr stopover on way back in reverse direction. I won't do it again unless I go at least premium economy.
Edelweiss
Guru
Many years ago there was a 20+ hour non stop flight from Chicago, Ill to Perth, Aus. At the time, it was billed as the longest regularly scheduled non stop passenger flight in the world. Don't remember the airline, might have been Qantas, but had two flight crews on a long haul 747.
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Even with the layover that would still be a killer for me Peter. My regular trip is 9 hours to Heathrow, 2 or 3 hr layover, 2 hours to Madrid. Overnight there, then next morning 2 hr high speed train to Valencia and I'm dead for the next 2 days.
I usually fly British Airways.
Yes premium economy gives you a better seat, fewer passengers and if available a bulk head facing seat gives you much more leg room. Down side they won't let you use the head on the other side of the bulkhead which is Business Class. Have to walk through Premium and Economy to the tail of the plane and compete for the two heads there.
Ooops!!
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Even with the layover that would still be a killer for me Peter. My regular trip is 9 hours to Heathrow, 2 or 3 hr layover, 2 hours to Madrid. Overnight there, then next morning 2 hr high speed train to Valencia and I'm dead for the next 2 days.
I usually fly British Airways.
Yes premium economy gives you a better seat, fewer passengers and if available a bulk head facing seat gives you much more leg room. Down side they won't let you use the head on the other side of the bulkhead which is Business Class. Have to walk through Premium and Economy to the tail of the plane and compete for the two heads there.
Ooops!!
Fortunately, our corporate policy was any flight over 6 hours was first class.
I once missed Thanksgiving on a trip to Australia. On Wednesday morning, I flew out of NC to Chicago and connected to LA. From LA we had a stop in Hawaii. Then on to Sydney. We crossed the international time line almost precisely at midnight and arrived in Australia on Friday morning around 9 AM. I had 6 meals in the combination of flights but no Thanksgiving type meal, no turkey, no dressing. That year, the day just didn't exist. Now coming back was nice, arriving in Honolulu before I left Sydney. I don't think the direct flights still exist today. In elapsed time I spent about 32 hours on that trip from the time I left NC until I landed in Sydney. Wasn't originally supposed to go to Chicago but something about the flight to LA was a turnaround and was going to be three hours late so would miss my flight to Honolulu.
I once missed Thanksgiving on a trip to Australia. On Wednesday morning, I flew out of NC to Chicago and connected to LA. From LA we had a stop in Hawaii. Then on to Sydney. We crossed the international time line almost precisely at midnight and arrived in Australia on Friday morning around 9 AM. I had 6 meals in the combination of flights but no Thanksgiving type meal, no turkey, no dressing. That year, the day just didn't exist. Now coming back was nice, arriving in Honolulu before I left Sydney. I don't think the direct flights still exist today. In elapsed time I spent about 32 hours on that trip from the time I left NC until I landed in Sydney. Wasn't originally supposed to go to Chicago but something about the flight to LA was a turnaround and was going to be three hours late so would miss my flight to Honolulu.
