We have a 2000 watt Honda inverter/generator- very quiet (57 dB, IIRC). Runs the air conditioner in the pickup camper, but not much capacity for anything else. I was thinking of getting another- you can hook them together and they synchronize, so you get 4000 watts. Mrs. (WA) said "But then it would be twice as loud, and that wouldn't work in a camp." I don't know anything about the mechanics of sound, so am wondering- if I have 2 items generating 57 dB each, will the result be twice as loud? Or the same? Or something in between?
- Thread starter Mike (WA)
- Start date
buickanddeere
Well-known Member
With enough time and money the generators could be set up to cancel each other's sound and operate soundlessly.
b.t.w. sound is measured on the log scale. 60db would be twice as loud as 57db.
TomH in PA
Well-known Member
Mrs. (WA) is a smart woman. Look at the link below for "How are noise levels added?". And think about what happens when a crowd if people applaud - the combined noise is far louder than one person clapping. When I was in college you could hear the roar a mile away from the stadium when the football team made a big play.
Noise stuff
Noise stuff
Mike,
If have both generators running right next to each other (single point source) you should be in the 60 dB range.
You set one on each side of your camper, then you wouldn't annoy the same neighbor with 60dB, you can annoy each one with 57 dB.
As B&D points out each 3 dB is about where the human ear perceives the sound as twice as loud as the previous sound.
I have found that traveling with a blender to make mixed drinks with your generator gets you all sorts of friends at the campground and they soon forget about the noise. My 3500 Honda is WAY louder than my dads Honda 2000.
If have both generators running right next to each other (single point source) you should be in the 60 dB range.
You set one on each side of your camper, then you wouldn't annoy the same neighbor with 60dB, you can annoy each one with 57 dB.
As B&D points out each 3 dB is about where the human ear perceives the sound as twice as loud as the previous sound.
I have found that traveling with a blender to make mixed drinks with your generator gets you all sorts of friends at the campground and they soon forget about the noise. My 3500 Honda is WAY louder than my dads Honda 2000.
Badger bob
Member
all I know is that I work for the local county running a road grader . when I first started it was very loud. but now after 10 yr,s its not nearly as loud. LOL Bob
no it will not be twice as loud.
The sound will be more complex and more full, but not twice as "loud".
Think of it this way. If you had 10 stereo systems in a room, and they were all set to the same volume - and you turned one on... then another, it wouldn't be twice as loud. If you turned all 10 on, it wouldn't be 10 times as loud.
The sound will be more complex and more full, but not twice as "loud".
Think of it this way. If you had 10 stereo systems in a room, and they were all set to the same volume - and you turned one on... then another, it wouldn't be twice as loud. If you turned all 10 on, it wouldn't be 10 times as loud.
MarkB_MI
Well-known Member
- Location
- Motown USA
Any hi-fi buff (do they still exist?) will tell you that doubling the power output of a sound system won't double its volume.
Doubling the power into a sound source raises the sound level by 3 decibels. Which is perceptible, but barely so. Also, just because you have a 4000 watt capacity doesn't mean you're generating 4000 watts all the time. For the most part, the two generators will be loafing along, each putting out a thousand watts.
Doubling the power into a sound source raises the sound level by 3 decibels. Which is perceptible, but barely so. Also, just because you have a 4000 watt capacity doesn't mean you're generating 4000 watts all the time. For the most part, the two generators will be loafing along, each putting out a thousand watts.
Geo-TH,In
Well-known Member
Mike, why do you need twice the power? Why do you need to tie two together? Use one for A/C and the other for whatever.
Last year I made an energy management system, using old electronic components I had on the shelf from furnaces and A/c's, to control where I send the power from my 3500 w RV genny. My well has priority over everything else. When pump comes on, everything else is turned off. When pump shuts off, power is returned appliances first, lamp, toaster, electric grill, then depending on where I have the delay timer set, around 5 minutes, the refrig gets power. I like delaying the refrig's power so I don't short cycle it.
So, why not manage the power from your genny? A/c has priority. When A/c shuts off send power to charge camper battery or run the other things.
You are camping right, not staying at the Holiday Inn? So why not manage your power?
George
Last year I made an energy management system, using old electronic components I had on the shelf from furnaces and A/c's, to control where I send the power from my 3500 w RV genny. My well has priority over everything else. When pump comes on, everything else is turned off. When pump shuts off, power is returned appliances first, lamp, toaster, electric grill, then depending on where I have the delay timer set, around 5 minutes, the refrig gets power. I like delaying the refrig's power so I don't short cycle it.
So, why not manage the power from your genny? A/c has priority. When A/c shuts off send power to charge camper battery or run the other things.
You are camping right, not staying at the Holiday Inn? So why not manage your power?
George
I've been in campgrounds where there were a dozen of those inane things running. As much as I hate them -having 12 running all at once certainly did not make the noise 12 times as bad. Just a constant low hum, coming from almost all directions instead of one. As far a using dB ratings? Never fully understood using those numbers so they make practical sense. dB is one-tenth of a "Bell" unit named after Adam Graham Bell and devised by Ma Bell labs. Generator dB ratings often get fudged and don't mean much unless distances are given. I've had generators rated at 59 dB that sounded quieter then those rated at 57 dB.
The neighbors at a campground will hate you for 2 just the same as they will hate you for 1 generator, pairing them up will be about the same.
Lots of discussions on the internet about this, many people have done it. Here is one with links to more. http://www.airforums.com/forums/f44...0i-vs-two-paralleled-honda-eu2000i-44129.html
But why trust people on the internet? It shouldnt be too hard to find somebody local with another generator that you can pair up with yours. I would recommend a dealer but then you may feel obligated to buy from him after a test listen, if you find another camper to pair your generator with you can feel free to order online.
Lots of discussions on the internet about this, many people have done it. Here is one with links to more. http://www.airforums.com/forums/f44...0i-vs-two-paralleled-honda-eu2000i-44129.html
But why trust people on the internet? It shouldnt be too hard to find somebody local with another generator that you can pair up with yours. I would recommend a dealer but then you may feel obligated to buy from him after a test listen, if you find another camper to pair your generator with you can feel free to order online.
If you're going to join two generators on the same grid you need to know what you're doing and it's a little more involved than just hooking the wires together.
Best Read This First...
Best Read This First...
buickanddeere
Well-known Member
The Honda and Champion inverter generator have built in jacks to parallel the output power and signal cables to sync the machines together.
hoof print
Member
generally, it would take 10 times as many generators to be twice as loud as one.
Sounds like a lot of work, George, unless you're an electronics buff and enjoy doing that sort of thing. I want to just plug the camper cord into them and then go roast some marshmallows or something.
Everybody's point about noisy generators in campgrounds is well taken. I'd never use one in a public campground, but Mrs. (WA) goes up in the mountains, or to horse events, and the quiet Hondas are pretty much accepted as a necessary evil, at least where there are no hookups. The $299 Auto Zone specials will get shut down in a hurry by the angry neighbors, but the Hondas just keep humming along.
Everybody's point about noisy generators in campgrounds is well taken. I'd never use one in a public campground, but Mrs. (WA) goes up in the mountains, or to horse events, and the quiet Hondas are pretty much accepted as a necessary evil, at least where there are no hookups. The $299 Auto Zone specials will get shut down in a hurry by the angry neighbors, but the Hondas just keep humming along.
Sound decibels are measured on a logarithmic scale, it's not linear. Other common logarithmic scales are: the pH scale for measuring acidity and alkalinity, and the Richter scale for measuring earthquakes.
Doubling the noise (sound energy) increases the number of decibels by three. If one generator makes 57 decibels, then two generators will make 60 decibels. Doubling that 2 x 2 = 4 generators would make 63 decibels. Doubling that 2 x 4 = 8 generators would make 66 decibels. Doubling that
2 x 8 = 16 generators would make 69 decibels, etc.
Doubling the noise (sound energy) increases the number of decibels by three. If one generator makes 57 decibels, then two generators will make 60 decibels. Doubling that 2 x 2 = 4 generators would make 63 decibels. Doubling that 2 x 4 = 8 generators would make 66 decibels. Doubling that
2 x 8 = 16 generators would make 69 decibels, etc.
Geo-TH,In
Well-known Member
You aren't the first person with loud gennies. Have a friend with a briggs genny and his neighbors 2 blocks away know when his is running.
Perhaps one could make money retro fitting mufflers to the loud ones.
My first energy management systems was made from scrap parts. I bought some parts for my second one, under $100. It gave me something to do last winter.
Perhaps one could make money retro fitting mufflers to the loud ones.
My first energy management systems was made from scrap parts. I bought some parts for my second one, under $100. It gave me something to do last winter.
I bet your single Honda 2000 is running pretty hard when the AC is on. Two 2000's in parallel won't be running nearly as hard so the overall noise will be reduced.
Speaking from experience here. Had two in parallel running the A/C, which is tolerable to sleep with. When one ran out of gas, the other one had to ramp up to full throttle to keep up with the load. Woke me right out of a sound sleep.
Speaking from experience here. Had two in parallel running the A/C, which is tolerable to sleep with. When one ran out of gas, the other one had to ramp up to full throttle to keep up with the load. Woke me right out of a sound sleep.
Bob, My Dad ran grader for around 20 yrs for NYSDOT, a 64 Galion(sp), it was same grader all those years. He said same thing about it not being as loud in the end.
Boy that thing would bark when worked hard and the muffler had fallen off.
Some how he ended up with 3 hearing aids. As a kid I used to ride with him sometimes and guess what, I now NEED hearing aids too. Hopefully I can get away with only 2 LOL
Boy that thing would bark when worked hard and the muffler had fallen off.
Some how he ended up with 3 hearing aids. As a kid I used to ride with him sometimes and guess what, I now NEED hearing aids too. Hopefully I can get away with only 2 LOL
NO, tell the little woman Ol John T said its NOT twice as loud and YES the two can easily be connected in parallel (if so equipped to allow such) no problem.
That being said and as one who has dry camped countless times in countless locations and heard all types and brands and sizes of them gennys runnin all night, heres something to think about if your existing unit isn't big enough.
If you look at the cost of two units and the hassle of carrying them and connecting them and keeping both gassed up WHY NOT SELL THE ONE (NOT have to buy a second unit) AND BUY A 3000 WATT HONDA OR YAMAHA OR OTHER QUALITY GENSET??? I say that because those units seem sooooooooooooo quiet and of course have the power to run the AC plus Microwave etc etc and its so much easier then packing two gensets and gassing both etc.
What I hated most or maybe even moved if it happened was a dude coming in with one of those cheap loud screaming gensets form Big Box Store running loud n wide open and LOUD all night grrrrrrrrrr
A while back on You Tube I saw some demonstrations of some Hyundai (I cant spell it) gensets that made them look very good and quiet and ability to run AC/s etc yet much cheaper then the Honda or Yamaha CHECK IT OUT
Im currently running an Onan 4KW so called "Microquiet" YEAH RIGHT genset which works fine. HOWEVER its a single cylinder 3600 RPM louder (still MUCH quieter then big box store screaming loud cheap genset) then the older Onans which were two cylinder and only ran at 1800 RPM. If mine ever crapped out Id replace it with an older quieter 1800 RPM two cylinder In a heartbeat. However having Solar Panels and 460 Amp Hrs (4 golf cart batteries) of battery storage means and since my fridge can run on LP Gas (or 120 VAC when available, I have two choices) when I'm dry camping, I don't need to run my genny much at all.
Think it over Mike. On my next trip to Crater Lake lets camp together????
PS that was July 5, the road all the way around the lake was still snow closed July 4 lol
John T
That being said and as one who has dry camped countless times in countless locations and heard all types and brands and sizes of them gennys runnin all night, heres something to think about if your existing unit isn't big enough.
If you look at the cost of two units and the hassle of carrying them and connecting them and keeping both gassed up WHY NOT SELL THE ONE (NOT have to buy a second unit) AND BUY A 3000 WATT HONDA OR YAMAHA OR OTHER QUALITY GENSET??? I say that because those units seem sooooooooooooo quiet and of course have the power to run the AC plus Microwave etc etc and its so much easier then packing two gensets and gassing both etc.
What I hated most or maybe even moved if it happened was a dude coming in with one of those cheap loud screaming gensets form Big Box Store running loud n wide open and LOUD all night grrrrrrrrrr
A while back on You Tube I saw some demonstrations of some Hyundai (I cant spell it) gensets that made them look very good and quiet and ability to run AC/s etc yet much cheaper then the Honda or Yamaha CHECK IT OUT
Im currently running an Onan 4KW so called "Microquiet" YEAH RIGHT genset which works fine. HOWEVER its a single cylinder 3600 RPM louder (still MUCH quieter then big box store screaming loud cheap genset) then the older Onans which were two cylinder and only ran at 1800 RPM. If mine ever crapped out Id replace it with an older quieter 1800 RPM two cylinder In a heartbeat. However having Solar Panels and 460 Amp Hrs (4 golf cart batteries) of battery storage means and since my fridge can run on LP Gas (or 120 VAC when available, I have two choices) when I'm dry camping, I don't need to run my genny much at all.
Think it over Mike. On my next trip to Crater Lake lets camp together????
PS that was July 5, the road all the way around the lake was still snow closed July 4 lol
John T
Nancy Howell
Well-known Member
I have a Champion 4000 watt, RV ready genny. Paid $300 at TSC, then an additional $50 for the wheel kit.
Decibels are 68, a bit more than what you currently have, but not bad, and all the power you will ever need for your camper.
Easily powers the living quarters on my horse trailer.
Decibels are 68, a bit more than what you currently have, but not bad, and all the power you will ever need for your camper.
Easily powers the living quarters on my horse trailer.
Main reason for 2 is that a single 3000 Watt is quite a bit heavier, and the 2000 is about all she can handle. Has to transport it in the tack room of the horse trailer, so has to be liftable for her. Would also be handy to have more capacity at home when the power goes out- have to alternate the fridge and 2 freezers on the one.
Good answer just below from a guy who has btdt. One makes more noise at combat speed than 2 just loafing along.
Good answer just below from a guy who has btdt. One makes more noise at combat speed than 2 just loafing along.
Geo-TH,In
Well-known Member
I have two champion 3500-4000 max. My first was only $300 new at TSC. Second one I got from Home Depot. It came with wheels, hour meter, frequency meter, volt meter, 12v battery, remote electric start for another $160. I think it's money well spent.
Now to answer the question, will two gennerators sound louder, my answer is Yes.
Wave theory states when you have two waves, you will get the algebraic sum and difference between the waves. So 2 crests will add, 2 troughs will add, a crest and a trough the same size will cancel out.
Without a db meter, I will guess 2 gennies together will have a 3 db gain, twice the sound power.
Now to answer the question, will two gennerators sound louder, my answer is Yes.
Wave theory states when you have two waves, you will get the algebraic sum and difference between the waves. So 2 crests will add, 2 troughs will add, a crest and a trough the same size will cancel out.
Without a db meter, I will guess 2 gennies together will have a 3 db gain, twice the sound power.
Geo-TH,In
Well-known Member
hoof print
Member
(quoted from post at 00:06:50 11/13/14)our words don't match the chart. Chart is correct. Two, twice as loud.(quoted from post at 00:36:47 11/12/14) generally, it would take 10 times as many generators to be twice as loud as one.
Read ss55's post above. He explained it very well.
SO FAR... No one has noticed that they are inverter type generators. and as such they vary the gas and rpms to the load as they recreated the power through an inverter system that corrects the frequency... SO... generator rpms, and noise is according to power draw. The hondas will share the load and each generator will drop to half of the old load plus any add ons.. So its possible two generators at half load could be less noisy than one generator at near full load. Or Not...
SO.. now we really throw a wrench into the calculations. And will the share perfectly equal, or somewhat equal...
the eu series of hondas are very quiet generators...
MarkB_MI
Well-known Member
- Location
- Motown USA
The vertical axis is in decibels, which is a logarithmic scale. Two generators means an increase of 3 db, which is barely perceptible.
Geo-TH,In
Well-known Member
Jessie,
Look what happens when 20 Harleys are on a rally.
Very loud!
I looked at the dbs on honda's. They give a range
of db, probably determined by load.
So, what is the db rating of a equal size 4000
honda vs the next quieter genny?
Mufflers work on wave theory, destructive
interference. Read once that someone is working
on an electronic muffler. Like the sound
canceling headset I use when target practicing.
I'm thinking there is money to be made is someone
makes a better after market muffler for
generators,
George
Look what happens when 20 Harleys are on a rally.
Very loud!
I looked at the dbs on honda's. They give a range
of db, probably determined by load.
So, what is the db rating of a equal size 4000
honda vs the next quieter genny?
Mufflers work on wave theory, destructive
interference. Read once that someone is working
on an electronic muffler. Like the sound
canceling headset I use when target practicing.
I'm thinking there is money to be made is someone
makes a better after market muffler for
generators,
George
have read about electronic mufflers in the experimental stage at least, but know of no production. Even with a perfect muffler, the single cylinder engines still would not be real quiet, as the fins around the cylinders & all attached parts are vibrating like a speaker cone & sending out a lot of sound pressure waves. I remember the big change from air cooled to water jacketed engines in Porsche, Harley & others & the fin/other vibrations were found to be the source of much of the noise. My Miller 2E was/is stupid noisy, so I added a Corolla muffler ahead of the Miller/Tecumseh muffler & yes the exhaust noise went down, but all that 'other' noise is still terrible. A lot of shaking going on.
On the main topic here, concerning adding sources........it is far more complex that adding the dB ratings. Phase, reflections, distance between machines vs frequency (complex of frequencies), distance from each to observer, and on & on. Interesting discussion , but not many absolutes other than maybe decibel = 10log2 = 3dB. Then complicate that with the complex human who does not perceive that doubling of power as twice as loud. What is the meaning of life. :roll:
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